66 research outputs found

    Block Polyelectrolyte Additives That Modulate the Viscoelasticity and Enhance the Printability of Gelatin Inks at Physiological Temperatures

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    We demonstrate the utility of block polyelectrolyte (bPE) additives to enhance viscosity and resolve challenges with the three-dimensional (3D) printability of extrusion-based biopolymer inks. The addition of oppositely charged bPEs to solutions of photocurable gelatin methacryloyl (GelMA) results in complexation-driven self-assembly of the bPEs, leading to GelMA/bPE inks that are printable at physiological temperatures, representing stark improvements over GelMA inks that suffer from low viscosity at 37 °C, leading to low printability and poor structural stability. The hierarchical microstructure of the self-assemblies (either jammed micelles or 3D networks) formed by the oppositely charged bPEs, confirmed by small-angle X-ray scattering, is attributed to the enhancements in the shear strength and printability of the GelMA/ bPE inks. Varying bPE concentration in the inks is shown to enable tunability of the rheological properties to meet the criteria of pre- and postextrusion flow characteristics for 3D printing, including prominent yielding behavior, strong shear thinning, and rapid recovery upon flow cessation. Moreover, the bPE self-assemblies also contribute to the robustness of the photo-cross- linked hydrogels; photo-cross-linked GelMA/bPE hydrogels are shown to exhibit higher shear strength than photo-cross-linked GelMA hydrogels. Last, the assessment of the printability of GelMA/bPE inks indicates excellent printing performance, including minimal swelling postextrusion, satisfactory retention of the filament shape upon deposition, and satisfactory shape fidelity of the various printed constructs. We envision this study to serve as a practical guide for the printing of bespoke extrusion inks where bPEs are used as scaffolds and viscosity enhancers that can be emulated in a range of photocurable precursors

    A CTMC-based characterisation of the propagation of errors in GMPLS Optical Rings

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    Abstract: This article presents a Continuous-Time Markov Chain model to characterise the propagation of failures in optical GMPLS rings. In order to characterize the behaviour of failure propagation epidemic-based models are commonly used. However, the existing epidemic models do not take into account the specific features of a multilayer network environment. A node failure in GMPLS-based networks can affect: Control Plane and Data plane reporting different failures scenarios. Consequently, an extended generic epidemic model called SID is proposed, in order to cover multiple failures and recovered states in a GMPLS Multilayer scenario. The CTMC model takes into account the SID model and provides a set of design rules to specify the values of repair rates required to achieve a given service availability, assuming a certain infection and disable rate.The work described in this paper was carried out with the support of the BONE project (''Building the Future Optical Network in Europe''), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Programme. Additionally, the authors would like to thank the support of the T2C2 Spanish project (under code TIN2008-06739-C04-01) and the Madrid Community through the MEDIANET project (S-2009/TIC-1468) to the development of this work. This work is partially supported by Spanish Ministry of Science and Innovation project TEC 2009-10724 and by Generalitat de Catalunya research support program (SGR-1202).Publicad

    In vitro activity of essential oils against microbial isolates from otitis externa cases in dogs

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    [EN] Despite the number of studies focused on the potential use of essential oils (EOs) as an alternative to conventional treatments of canine external otitis, there is controversy about their antimicrobial activity which could be explained by differences in technical or biological aspects. This study focuses on the antimicrobial activity of three single EO compounds (thymol, cinnamaldehyde and carvacrol) and two EOs (clove and oregano) against clinical isolates recovered from canine otitis externa cases (14 bacterial isolates belonging to five different genera and six Malassezia pachydermatis isolates). All compounds showed activity and cinnamaldehyde exhibited the highest bactericidal and fungicidal activity. The susceptibility was lower among bacterial isolates than fungal isolates, being this difference more evident for Gram-positive bacteria. No relationship between antibiotic multi-resistant profile and susceptibility to compounds was observed. To sum up, our results provide appropriate information about appropriate concentrations of promising candidates for the topic treatment of canine otitis.SIManuel Gómez-García was supported by grant from Junta de Castilla y León co-financed by the European Social Fund (LE131-18). Héctor Puente (FPU17/00466) and Óscar Mencía-Ares (FPU16/03485) were supported by the Spanish Ministry of Education. Héctor Argüello was supported by the Spanish Ministry of Education under the programme Beatriz Galindo (BEAGAL-18-106)

    Molecular-scale substrate anisotropy and crowding drive long-range nematic order of cell monolayers

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    The ability of cells to reorganize in response to external stimuli is important in areas ranging from morphogenesis to tissue engineering. Elongated cells can co-align due to steric effects, forming states with local order. We show that molecular-scale substrate anisotropy can direct cell organization, resulting in the emergence of nematic order on tissue scales. To quantitatively examine the disorder-order transition, we developed a high-throughput imaging platform to analyze velocity and orientational correlations for several thousand cells over days. The establishment of global, seemingly long-ranged order is facilitated by enhanced cell division along the substrate's nematic axis, and associated extensile stresses that restructure the cells' actomyosin networks. Our work, which connects to a class of systems known as active dry nematics, provides a new understanding of the dynamics of cellular remodeling and organization in weakly interacting cell collectives. This enables data-driven discovery of cell-cell interactions and points to strategies for tissue engineering.Comment: 29 pages, 7 figure

    Herramientas de software con licencia pública general para el modelado por elementos finitos

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    En el presente artículo se presentan los resultados de una revisión realizada a varios programas con licencias GPL para el modelamiento de problemas con elementos finitos. Este estudio permitió realizar la caracterización de estos programas teniendo en cuenta criterios como el tipo de análisis permitido, la compatibilidad con programas CAD, el tipo de soporte ofrecido, la actualización de las versiones, el tipo de interfaz de usuario implementado y la curva de aprendizaje para nuevos usuarios, entre otros. Posteriormente se estudiaron tres casos diferentes, los cuales fueron modelados con elementos finitos empleando distintos programas GPL. En la parte final del documento se comparan los resultados obtenidos con software libre, los arrojados por un programa comercial (Ansys), y los modelos analíticos derivados de la solución de la ecuación diferencial que rige el fenómeno particular, obteniendo una convergencia aceptable entre todos los resultado

    Determinants of long-term survival in late HIV presenters : The prospective PISCIS cohort study

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    Late HIV diagnosis (i.e CD4≤350 cells/µL) is associated with poorer outcomes. However, determinants of long-term mortality and factors influencing immune recovery within the first years after antiretroviral treatment (ART) initiation are poorly defined. From PISCIS cohort, we included all HIV-positive adults, two-year survivors after initiating ART between 2005-2019. The primary outcome was all-cause mortality according to the two-year CD4 count. We used Poisson regression. The secondary outcome was incomplete immune recovery (i.e., two-year CD4500 cells/µL, reference population). Overall, 113 patients (4·2%) died. Mortality was higher among LP with two-year CD4 count 200-500 cells/µL (aMRR 1·95[95%CI:1·06-3·61]) or 500 cells/µL, regardless of being initially LP or non-LP (aMRR 1·05[0·50-2·21]). Mortality rates within each two-year CD4 strata were not affected by the initial CD4 count at ART initiation (test-interaction, p = 0·48). The stronger factor influencing immune recovery was the CD4 count at ART initiation. First-line integrase-inhibitor-(INSTI)-based regimens were associated with reduced mortality compared to other regimens (aMRR 0·54[0·31-0·93]) and reduced risk of incomplete immune recovery in LP (aOR 0·70[0·52-0·95]). Two-year immune recovery is a good early predictor of long-term mortality in LP after surviving the first high-risk 2 years. Nearly half experienced a favorable immune recovery with a life expectancy similar to non-LP. INSTI-based regimens were associated with higher rates of successful immune recovery and better survival compared to non-INSTI regimens. Southern-Denmark University, Danish AIDS-foundation, and Region of Southern Denmark

    Ciberseguridad : el reto del siglo XXI

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    El siglo XXI es el siglo del dato, su análisis y de la conectividad; en definitiva, el siglo de la información en tiempo real y disponible para cualquiera en cualquier lugar del mundo. Dichos datos están impactando en todos los ámbitos de la sociedad y de la economía de tal forma que no se entiende ningún sector productivo ni ninguna relación social sin dato; todos tenemos algún lugar en las redes sociales desde donde intercambiamos experiencias personales o profesionales. Si a este hecho se le suma el auge de la Inteligencia Artificial, se tiene un siglo en el que los avances tecnológicos van a ser totalmente disruptivos para todos nosotros

    Prevalencia de síntomas de asma en los niños y adolescentes de la Comunidad Autónoma de Galicia (España) y sus variaciones geográficas

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    OBJECTIVES: To determine the prevalence and geographic variations of the symptoms associated with asthma in Galician children and adolescents. POPULATION AND METHODS: A cross-sectional epidemiological study following ISAAC (International Study of Asthma and Allergies in Childhood) methodology, and using a written questionnaire distributed in schools. The study sample included 10,371 6-7 year-old children and 10,372 13-14 year-old adolescents, all of them from Galician Health Areas. A logistic regression model was used to analyse geographic variations. RESULTS: In the 6-7 year-old group, wheezing in the last 12 months varied from 11.4% (Santiago) to 15.7% (Vigo) and in the adolescents varied from 8.8% (Ourense) to 18.8% (Vigo). The distribution by gender showed a predominant significance in 6-7 year-old males (P<.001), and near to be statistically significant in 13-14 year-old females (P=.08). The risk (odds ratio [OR]) of wheezing in the last 12 months in the area with highest prevalence in comparison with the area of lowest prevalence was 1.45 (95% Confidence Interval [CI], 1.12-1.88) for children and 2.39 (95% CI, 1.82-3.13) for adolescents. The estimated prevalence of asthma in the Autonomous Community of Galicia was 13.6% in younger children and 12.2% in adolescents. CONCLUSIONS: The prevalence of wheezing in the last 12 months in the different areas of Galicia is considerably higher than the rest of Spanish ISAAC cities in the 6-7 years group and very similar in the 13-14 years group, except in Vigo where it is considerably higher. We found a clearly defined geographic pattern in the adolescent group, with higher prevalences in coastal areas than in the interior

    Strategies to reengage patients lost to follow up in HIV care in high income countries, a scoping review

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    Background: Despite remarkable achievements in antiretroviral therapy (ART), losses to follow-up (LTFU) might prevent the long-term success of HIV treatment and might delay the achievement of the 90-90-90 objectives. This scoping review is aimed at the description and analysis of the strategies used in high-income countries to reengage LTFU in HIV care, their implementation and impact. Methods: A scoping review was done following Arksey & O'Malley's methodological framework and recommendations from Joanna Briggs Institute. Peer reviewed articles were searched for in Pubmed, Scopus and Web of Science; and grey literature was searched for in Google and other sources of information. Documents were charted according to the information presented on LTFU, the reengagement procedures used in HIV units in high-income countries, published during the last 15 years. In addition, bibliographies of chosen articles were reviewed for additional articles. Results: Twenty-eight documents were finally included, over 80% of them published in the United States later than 2015. Database searches, phone calls and/or mail contacts were the most common strategies used to locate and track LTFU, while motivational interviews and strengths-based techniques were used most often during reengagement visits. Outcomes like tracing activities efficacy, rates of reengagement and viral load reduction were reported as outcome measures. Conclusions: This review shows a recent and growing trend in developing and implementing patient reengagement strategies in HIV care. However, most of these strategies have been implemented in the United States and little information is available for other high-income countries. The procedures used to trace and contact LTFU are similar across reviewed studies, but their impact and sustainability are widely different depending on the country studied

    Spread of a SARS-CoV-2 variant through Europe in the summer of 2020

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    [EN] Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3,4,5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes.S
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