Biomolecular imaging and electronic damage using X-ray free-electron lasers

Proposals to determine biomolecular structures from diffraction experiments using femtosecond X-ray free-electron laser (XFEL) pulses involve a conflict between the incident brightness required to achieve diffraction-limited atomic resolution and the electronic and structural damage induced by the illumination. Here we show that previous estimates of the conditions under which biomolecular structures may be obtained in this manner are unduly restrictive, because they are based on a coherent diffraction model that is not appropriate to the proposed interaction conditions. A more detailed imaging model derived from optical coherence theory and quantum electrodynamics is shown to be far more tolerant of electronic damage. The nuclear density is employed as the principal descriptor of molecular structure. The foundations of the approach may also be used to characterize electrodynamical processes by performing scattering experiments on complex molecules of known structure.Comment: 16 pages, 2 figure

PERSPECTIVAS DEL PROCESO DE GLOBALIZACIÓN Y SU INFLUENCIA SOBRE LOS DERECHOS HUMANOS ECONÓMICOS, SOCIALES Y CULTURALES

El escenario internacional se encuentra en constante transformación debido a lo que se ha denominado el proceso de “globalización”. Este afecta las relaciones internaciones interestatales e influye en la vida cotidiana de los individuos. El Derecho Internacional y más específicamente el Derecho Internacional de los Derechos Humanos no es ajeno a este proceso. La investigación afirma que nos encontramos frente a una etapa de transnacionalización de los Derechos Humanos, que permite que los individuos cuenten con mayor protección en ámbitos supranacionales. También hace especial mención a los derechos Económicos Sociales y Culturales, analiza el debate sobre el pluralismo jurídico y la eficacia diferencial. En la metodología empleada se revisan fuentes documentales y se realiza un análisis de algunos derechos particulares previstos en el Pacto de Derechos Económicos, Sociales y Culturales. Los planteamientos permiten afirmar que el proceso de globalización ha determinado la transnacionalización de los Derechos Humanos, surgiendo de dicho fenómeno consecuencias positivas y negativas en cuanto a su cumplimiento

Mesenchymal transformation of the epicardium contributes to the accumulation of epicardial adipose tissue in the atria

Congress of the European-Society-of-Cardiology (ESC), Rome, ITALY, AUG 27-31, 2016International audienceno abstrac

Atrial epicardial adipose tissue derives from epicardial progenitors

Frontiers in CardioVascular Biology Meeting (FCVB), Florence, ITALY, JUL 08-10, 2016International audienceno abstrac

Atrial epicardial adipose tissue derives from epicardial progenitors

Frontiers in CardioVascular Biology Meeting (FCVB), Florence, ITALY, JUL 08-10, 2016International audienceno abstrac

Circ Res

Rationale: Fibro-fatty infiltration of subepicardial layers of the atrial wall has been shown to contribute to the substrate of atrial fibrillation. Objective: Here, we examined if the epicardium that contains multipotent cells is involved in this remodeling process. Methods and Results: One hundred nine human surgical right atrial specimens were evaluated. There was a relatively greater extent of epicardial thickening and dense fibro-fatty infiltrates in atrial tissue sections from patients aged over 70 years who had mitral valve disease or atrial fibrillation when compared with patients aged less than 70 years with ischemic cardiomyopathy as indicated using logistic regression adjusted for age and gender. Cells coexpressing markers of epicardial progenitors and fibroblasts were detected in fibro-fatty infiltrates. Such epicardial remodeling was reproduced in an experimental model of atrial cardiomyopathy in rat and in Wilms tumor 1 (WT1)CreERT2/+;ROSA-tdT+/− mice. In the latter, genetic lineage tracing demonstrated the epicardial origin of fibroblasts within fibro-fatty infiltrates. A subpopulation of human adult epicardial-derived cells expressing PDGFR (platelet-derived growth factor receptor)-α were isolated and differentiated into myofibroblasts in the presence of Ang II (angiotensin II). Furthermore, single-cell RNA-sequencing analysis identified several clusters of adult epicardial-derived cells and revealed their specification from adipogenic to fibrogenic cells in the rat model of atrial cardiomyopathy. Conclusions: Epicardium is reactivated during the formation of the atrial cardiomyopathy. Subsets of adult epicardial-derived cells, preprogrammed towards a specific cell fate, contribute to fibro-fatty infiltration of subepicardium of diseased atria. Our study reveals the biological basis for chronic atrial myocardial remodeling that paves the way of atrial fibrillation