Direct visualization of the native structure of viroid RNAs at single-molecule resolution by atomic force microscopy

[EN] Viroids are small infectious, non-protein-coding circular RNAs that replicate independently and, in some cases, incite diseases in plants. They are classified into two families: Pospiviroidae, composed of species that have a central conserved region (CCR) and replicate in the cell nucleus, and Avsunviroidae, containing species that lack a CCR and whose multimeric replicative intermediates of either polarity generated in plastids self-cleave through hammerhead ribozymes. The compact, rod-like or branched, secondary structures of viroid RNAs have been predicted by RNA folding algorithms and further examined using different in vitro and in vivo experimental techniques. However, direct data about their native tertiary structure remain scarce. Here we have applied atomic force microscopy (AFM) to image at single-molecule resolution different variant RNAs of three representative viroids: potato spindle tuber viroid (PSTVd, family Pospiviroidae), peach latent mosaic viroid and eggplant latent viroid (PLMVd and ELVd, family Avsunviroidae). Our results provide a direct visualization of their native, three-dimensional conformations at 0 and 4 mM Mg2+ and highlight the role that some elements of tertiary structure play in their stabilization. The AFM images show that addition of 4 mM Mg2+ to the folding buffer results in a size contraction in PSTVd and ELVd, as well as in PLMVd when the kissing-loop interaction that stabilizes its 3D structure is preserved.This work was supported by the Spanish Ministerio de Economia y Competitividad (MINECO) grants BIO2016-79618-R (funded by EU under the FEDER programme) to C.B. and BFU2104-56812-P to R.F., as well as by the Comunidad de Madrid grant S2018/NMT-4349 to L.V. 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Versatile Graphene-Based Platform for Robust Nanobiohybrid Interfaces

Technologically useful and robust graphene-based interfaces for devices require the introduction of highly selective, stable, and covalently bonded functionalities on the graphene surface, whilst essentially retaining the electronic properties of the pristine layer. This work demonstrates that highly controlled, ultrahigh vacuum covalent chemical functionalization of graphene sheets with a thiol-terminated molecule provides a robust and tunable platform for the development of hybrid nanostructures in different environments. We employ this facile strategy to covalently couple two representative systems of broad interest: metal nanoparticles, via S-metal bonds, and thiol-modified DNA aptamers, via disulfide bridges. Both systems, which have been characterized by a multi-technique approach, remain firmly anchored to the graphene surface even after several washing cycles. Atomic force microscopy images demonstrate that the conjugated aptamer retains the functionality required to recognize a target protein. This methodology opens a new route to the integration of high-quality graphene layers into diverse technological platforms, including plasmonics, optoelectronics, or biosensing. With respect to the latter, the viability of a thiol-functionalized chemical vapor deposition graphene-based solution-gated field-effect transistor array was assessed

Evaluación de la enseñanza a través de la guía docente en la UPCT

[SPA]Este trabajo presenta una propuesta de metodología para la evaluación de guías docentes basada en un conjunto de tres criterios principales (utilidad, coherencia e idoneidad), once subcriterios y una serie de indicadores cuyos valores se obtienen a través de cuestionarios dirigidos a centros, departamentos, estudiantes y profesorado. Los cuestionarios parten del modelo de Guía Docente adoptado por la UPCT y contemplan todos los apartados de la misma. El método propuesto puede aplicarse también para mejorar los programas de evaluación del profesorado, pues aporta las evidencias que se necesitan para valorar la labor de planificación desarrollada por el mismo, la cual se plasma en la guía docente. [ENG]This paper presents a methodological proposal for the evaluation of teaching guides based on three main criteria, i.e. usefulness, consistency, and suitability, and eleven subcriteria. It is also based on different indicators obtained through questionnaires aimed at Educational Centres, Departments, Students and Professors. These questionnnaires have been prepared from the teaching guide model adopted by the Technical University of Cartagena (UPCT), and considering all the sections included in that guide. The proposed methodology can be also used to improve the teaching staff evaluation program, because of the inclusion of planning task carried out by the professor, an aspect considered in the teaching guide.Campus Mare Nostrum, Universidad Politécnica de Cartagena, Universidad de Murcia, Región de Murcia

International lower limb collaborative (INTELLECT) study: a multicentre, international retrospective audit of lower extremity open fractures

Trauma remains a major cause of mortality and disability across the world1, with a higher burden in developing nations2. Open lower extremity injuries are devastating events from a physical3, mental health4, and socioeconomic5 standpoint. The potential sequelae, including risk of chronic infection and amputation, can lead to delayed recovery and major disability6. This international study aimed to describe global disparities, timely intervention, guideline-directed care, and economic aspects of open lower limb injuries

Salmonella Strains Isolated from Galápagos Iguanas Show Spatial Structuring of Serovar and Genomic Diversity

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