31 research outputs found

    D and D-S decay constants from QCD duality at three loops

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    We compute the decay constants of the pseudoscalar mesons D and D_{s} using a linear combination of finite energy sum rules which minimize the contribution of the unknown continuum spectral function. We employ the recent three loop calculation of the pseudoscalar two-point function expanded in powers of the running charm quark mass. The theoretical uncertainties arising from the QCD asymptotic expansion are quite relevant in this case due to the relative small scale of the charm mass. We obtain the following results: f_{D}=177 \pm 21 MeV and f_{D_{s}}=205 \pm 22 MeV. These results, within the error bars, are in good agreement with estimates obtained using Borel transform QCD sum rules, but somewhat smaller than results of recent lattice computations

    Use of electrospinning to develop antimicrobial biodegradable multilayer systems: encapsulation of cinnamaldehyde and their physicochemical characterization

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    In this work, three active bio-based multilayer structures, using a polyhydroxybutyrate-co-valerate film with a valerate content of 8 % (PHBV8) as support, were developed. To this end, a zein interlayer with or without cinnamaldehyde (CNMA) was directly electrospun onto one side of the PHBV8 film and the following systems were developed: (1) without an outer layer; (2) using a PHBV8 film as outer layer; and (3) using an alginate-based film as outer layer. These multilayer structures were characterized in terms of water vapour and oxygen permeabilities, transparency, intermolecular arrangement and thermal properties. The antimicrobial activity of the active bio-based multilayer systems and the release of CNMA in a food simulant were also evaluated. Results showed that the presence of different outer layers reduced the transport properties and transparency of the multilayer films. The active bio-based multilayer systems showed antibacterial activity against Listeria monocytogenes being the multilayer structure prepared with CNMA and PHBV outer layers (PHBV + zein/CNMA + PHBV) the one that showed the greater antibacterial activity. The release of CNMA depended on the multilayer structures, where both Fick's and Case II transport-polymer relaxation explained the release of CNMA from the multilayer systems.Acknowledgments: Miguel A. Cerqueira (SFRH/BPD/72753/2010) andAnaI.Bourbon(SFRH/BD/73178/2010)arerecipientofafellowship from the Fundação para a Ciência e Tecnologia (FCT, POPH-QREN and FSE Portugal). J.L. Castro-Mayorga is supported by the Administrative Department of Science, Technology and Innovation (Colciencias) of Colombian Government. M. J. Fabra is a recipient of a Ramon y Cajal contract (RyC-2014-158) from the Spanish Ministry of Economy and Competitiveness. This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and of the Project RECI/BBB-EBI/ 0179/2012 (FCOMP-01-0124-FEDER-027462). The support of EU Cost Action MP1206 is gratefully acknowledged

    Genomics of perivascular space burden unravels early mechanisms of cerebral small vessel disease

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    Perivascular space (PVS) burden is an emerging, poorly understood, magnetic resonance imaging marker of cerebral small vessel disease, a leading cause of stroke and dementia. Genome-wide association studies in up to 40,095 participants (18 population-based cohorts, 66.3 ± 8.6 yr, 96.9% European ancestry) revealed 24 genome-wide significant PVS risk loci, mainly in the white matter. These were associated with white matter PVS already in young adults (N = 1,748; 22.1 ± 2.3 yr) and were enriched in early-onset leukodystrophy genes and genes expressed in fetal brain endothelial cells, suggesting early-life mechanisms. In total, 53% of white matter PVS risk loci showed nominally significant associations (27% after multiple-testing correction) in a Japanese population-based cohort (N = 2,862; 68.3 ± 5.3 yr). Mendelian randomization supported causal associations of high blood pressure with basal ganglia and hippocampal PVS, and of basal ganglia PVS and hippocampal PVS with stroke, accounting for blood pressure. Our findings provide insight into the biology of PVS and cerebral small vessel disease, pointing to pathways involving extracellular matrix, membrane transport and developmental processes, and the potential for genetically informed prioritization of drug targets.Etude de cohorte sur la santé des étudiantsStopping cognitive decline and dementia by fighting covert cerebral small vessel diseaseStudy on Environmental and GenomeWide predictors of early structural brain Alterations in Young student

    Clinical guide of the Spanish Society of Nephrology on the prevention and treatment of peritoneal infection in peritoneal dialysis

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    [Resumen] Las infecciones peritoneales siguen constituyendo una complicación muy relevante de la diálisis peritoneal, por su incidencia todavía elevada y por sus importantes consecuencias clínicas, en términos de mortalidad, fracaso de la técnica y costes para el sistema sanitario. Las prácticas de prevención y tratamiento de esta complicación muestran una notable heterogeneidad derivada, entre otros factores, de la complejidad del problema y de la escasez de evidencia clínica que permitan responder de manera clara a muchas de las dudas planteadas. El propósito de este documento es proporcionar una revisión completa y actualizada de los métodos de diagnóstico, prevención y tratamiento de estas infecciones. El documento se ha elaborado tomando como referencia de partida la guía más reciente de la Sociedad Internacional de Diálisis Peritoneal (2016). Mientras que para el capítulo diagnóstico se ha adoptado una estructura más narrativa, el análisis de las medidas de prevención y tratamiento ha seguido una metodología sistemática (Grading of Recommendations, Assessment, Development and Evaluation [GRADE]), que especifica el nivel de evidencia y la fuerza de las sugerencias y recomendaciones propuestas, y facilita actualizaciones futuras de la guía. La gran extensión y numerosas recomendaciones o sugerencias emanadas de la revisión ponen de manifiesto la complejidad y gran número de facetas a tener en cuenta para un adecuado abordaje de esta importante complicación de la diálisis peritoneal.[Abstract] Peritoneal infections still represent a most feared complication of chronic peritoneal dialysis, due to their high incidence and relevant clinical consequences, including direct mortality, technique failure and a significant burden for the health system. The practices for prevention and treatment of this complication show a remarkable heterogeneity emerging, among other factors, from the complexity of the problem and from a paucity of quality evidence which could permit to respond clearly to many of the raised questions. The purpose of this document is to provide a complete and updated review of the main methods of diagnosis, prevention and treatment of these infections. The document has been elaborated taking as a reference the most recent guidelines of the International Society of Peritoneal Dialysis (2016). The diagnostic considerations are presented in a narrative style while, for prevention and therapy, we have used a systematic methodology (Grading of Recommendations, Assessment, Development and Evaluation [GRADE]), which specifies the level of evidence and the strength of the proposed suggestions and recommendations and facilitates future updates of the document. The length of the document and the many suggestions and recommendations coming out of the review underline the large number and the complexity of the factors to be taken into consideration for an adequate approach to this complication of peritoneal dialysis

    Stroke genetics informs drug discovery and risk prediction across ancestries

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    Previous genome-wide association studies (GWASs) of stroke — the second leading cause of death worldwide — were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries

    THE SPACE OF STRING CONFIGURATIONS IN STRING FIELD THEORY

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    In this paper we consider the set of maps from the interval [0, π] which constitute the argument of the functionals of a String Field Theory. We show that in order to correctly reproduce results of the dual model one has to include all square integrable functions in the functional integral, or Ω0 in terms of Sobolev spaces
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