Los complejos triptasa-heparina de los mastocitos humanos y de ratón impiden la generación de fibrina y la coagulación del plasma inducida por la trombina mediante la destrucción proteolítica del fibrinógeno

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicina. Fecha de lectura: 27 de Mayo de 201

Evidence of the presence of nucleic acids and β-glucan in the matrix of non-typeable Haemophilus influenzae in vitro biofilms

13 p.-9 fig.Non-typeable Haemophilus influenzae (NTHi) is a Gram-negative bacterium that frequently colonizes the human nasopharynx; it is a common cause of chronic and recurrent otitis media in children and of exacerbations of chronic obstructive pulmonary disease. To date, no exopolysaccharide clearly contributing to NTHi biofilms has been identified. Consequently, there is some debate as to whether NTHi forms biofilms during colonization and infection. The present work shows that NTHi can form biofilms in vitro, producing an extracellular matrix composed of proteins, nucleic acids, and a β-glucan. Extracellular DNA, visualized by immunostaining and using fluorochromes, is an important component of this matrix and appears to be essential in biofilm maintenance. Extracellular RNA appears to be required only in the first steps of biofilm formation. Evidence of a matrix polysaccharide was obtained by staining with Calcofluor white M2R and by disaggregating biofilms with cellulase. Using strain 54997, residues of Glcp(1→4) in the NTHi biofilm were confirmed by gas-liquid chromatography-mass spectrometry. Evidence that N-acetyl-L-cysteine shows notable killing activity towards in vitro NTHi biofilm-forming bacteria is also provided.This work was supported by a grant from the Ministerio de Economía y Competitividad (SAF2012-39444-C02-01). The CIBER de Enfermedades Respiratorias (CIBERES) is an initiative of the Instituto de Salud Carlos III.Peer reviewe

Planificación, comunicación y metodologías activas: Evaluación online de la asignatura ingeniería de software durante la crisis del COVID-19

The coronavirus pandemic has had a high impact worldwide. The health crisis has not only had an impact on people's own health and on health systems, but has also affected other areas. In the educational context, the lockdown measures implemented by different governments have challenged the learning ecosystem. In the case of higher education in Spain, with a strong attendance factor in most public universities, face-to-face classes were interrupted after a month in the second term, ending the academic year in the online mode. This change has meant a great effort on the teachers’ side to transform the face-to-face teaching into the online approach, which in many cases has meant quite a comprehensive new design of the subject, changing the evaluation process and the methodologies used. This work presents a success case of online assessment developed in the Software Engineering I subject of the Degree in Computer Engineering at the University of Salamanca. The objective is to show how the previous use of active methodologies and the integration of educational technologies in classroom-based teaching facilitates the transformation of assessment to an online or blended approach while maintaining a high degree of student involvement and satisfaction. After presenting a comparison between the face-to-face approach and the adaptation to the online approach, an analysis is made of the learning results and student satisfaction concerning previous academic years. The results show that the change of approach has not reduced the satisfaction results obtained in previous courses. In terms of learning outcomes, there is an overall increase in the grades obtained by students in all assessment items.La pandemia de coronavirus ha tenido un alto impacto a nivel mundial. La crisis sanitaria no solo ha tenido un impacto en la propia salud de las personas y en los sistemas de salud, sino que ha afectado a otros ámbitos. En el contexto educativo, las medidas de confinamiento implementadas por los diferentes gobiernos han supuesto un reto para el ecosistema de aprendizaje. En el caso de la educación superior en España, con un fuerte componente presencial en la mayoría de las universidades públicas, se interrumpieron las clases presenciales un mes después del inicio del segundo cuatrimestre, finalizando el curso académico en modalidad online. Este cambio ha supuesto un gran esfuerzo por parte de los docentes para transformar la enseñanza presencial al enfoque online, lo que en muchos casos ha supuesto un rediseño casi integral de la asignatura, cambiando el proceso de evaluación y las metodologías utilizadas. El presente trabajo presenta un caso de éxito de evaluación online desarrollado en la asignatura Ingeniería de Software I del Grado en Ingeniería Informática de la Universidad de Salamanca. El objetivo es sustentar cómo el uso previo de metodologías activas y la integración de tecnologías educativas en la docencia presencial facilita la transformación de la evaluación a un enfoque online o mixto, a la par que mantiene un alto grado de implicación y satisfacción por parte de los estudiantes. Para ello, tras presentar una comparativa entre el enfoque presencial y la adaptación al enfoque online, se realiza un análisis de los resultados de aprendizaje y la satisfacción de los estudiantes respecto a los cursos académicos previos. Los resultados muestran que el cambio de enfoque no ha mermado los resultados de satisfacción obtenidos en los cursos anteriores. En cuanto a los resultados de aprendizaje, hay un aumento general de las calificaciones obtenidas por los estudiantes en todos los ítems de evaluación

Magnetosomes could be protective shields against metal stress in magnetotactic bacteria

Magnetotactic bacteria are aquatic microorganisms with the ability to biomineralise membrane-enclosed magnetic nanoparticles, called magnetosomes. These magnetosomes are arranged into a chain that behaves as a magnetic compass, allowing the bacteria to align in and navigate along the Earth's magnetic field lines. According to the magneto-aerotactic hypothesis, the purpose of producing magnetosomes is to provide the bacteria with a more efficient movement within the stratified water column, in search of the optimal positions that satisfy their nutritional requirements. However, magnetosomes could have other physiological roles, as proposed in this work. Here we analyse the role of magnetosomes in the tolerance of Magnetospirillum gryphiswaldense MSR-1 to transition metals (Co, Mn, Ni, Zn, Cu). By exposing bacterial populations with and without magnetosomes to increasing concentrations of metals in the growth medium, we observe that the tolerance is significantly higher when bacteria have magnetosomes. The resistance mechanisms triggered in magnetosome-bearing bacteria under metal stress have been investigated by means of x-ray absorption near edge spectroscopy (XANES). XANES experiments were performed both on magnetosomes isolated from the bacteria and on the whole bacteria, aimed to assess whether bacteria use magnetosomes as metal storages, or whether they incorporate the excess metal in other cell compartments. Our findings reveal that the tolerance mechanisms are metal-specific: Mn, Zn and Cu are incorporated in both the magnetosomes and other cell compartments; Co is only incorporated in the magnetosomes, and Ni is incorporated in other cell compartments. In the case of Co, Zn and Mn, the metal is integrated in the magnetosome magnetite mineral core.Te Spanish and Basque Governments are acknowledged for funding under projects number MAT2017- 83631-C3-R and IT-1245-19, respectively. Dr. L. Marcano acknowledges the fnancial support provided through a postdoctoral fellowship from the Basque Government

Modifying the magnetic response of magnetotactic bacteria: incorporation of Gd and Tb ions into the magnetosome structure

Magnetotactic bacteria Magnetospirillum gryphiswaldense MSR-1 biosynthesise chains of cube-octahedral magnetosomes, which are 40 nm magnetite high quality (Fe3O4) nanoparticles. The magnetic properties of these crystalline magnetite nanoparticles, which can be modified by the addition of other elements into the magnetosome structure (doping), are of prime interest in a plethora of applications, those related to cancer therapy being some of the most promising ones. Although previous studies have focused on transition metal elements, rare earth (RE) elements are very interesting as doping agents, both from a fundamental point of view (e.g. significant differences in ionic sizes) and for the potential applications, especially in biomedicine (e.g. magnetic resonance imaging and luminescence). In this work, we have investigated the impact of Gd and Tb on the magnetic properties of magnetosomes by using different complementary techniques. X-ray diffraction, transmission electron microscopy, and X-ray absorption near edge spectroscopy analyses have revealed that a small amount of RE ions, similar to 3-4%, incorporate into the Fe3O4 structure as Gd3+ and Tb3+ ions. The experimental magnetic characterisation has shown a clear Verwey transition for the RE-doped bacteria, located at T similar to 100 K, which is slightly below the one corresponding to the undoped ones (106 K). However, we report a decrease in the coercivity and remanence of the RE-doped bacteria. Simulations based on the Stoner-Wohlfarth model have allowed us to associate these changes in the magnetic response with a reduction of the magnetocrystalline (K-C) and, especially, the uniaxial (K-uni) anisotropies below the Verwey transition. In this way, K-uni reaches a value of 23 and 26 kJ m(-3) for the Gd- and Tb-doped bacteria, respectively, whilst a value of 37 kJ m(-3) is obtained for the undoped bacteria.This work was supported in part by the Spanish MCIN/AEI under Projects MAT2017-83631-C3-R and PID2020-115704RB-C33. The work of Elizabeth M. Jefremovas was supported by the "Concepci ' on Arenal Grant" awarded by Gobierno de Cantabria and Universidad de Cantabria. The work of Lourdes Marcano was supported by the Postdoctoral Fellowship from the Basque Government under Grant POS-2019-2-0017. The authors would like to thank "Nanotechnology in translational hyperthermia" (HIPERNANO)-RED2018-102626-T. We thank the ALBA (CLAESS beamline) synchrotron radiation facilities and staff for the allocation of beamtime and assistance during the experiments

Patrimonio académico como herramienta para el desarrollo de futuras carreras científicas

Desde hace tiempo la Unión Europea busca y fomenta la cooperación entre la Universidad y los Institutos de Educación Secundaria para el desarrollo de futuras carreras científicas. Después de varios proyectos de investigación competitivos desarrollados por separado, hemos encontrado importantes confluencias entre el patrimonio custodiado por la Universidad Complutense y el IES San Isidro; ambas instituciones cuentan con una larga historia y atesoran un patrimonio científico, artístico y educativo de gran interés que es necesario conectar y poner en valor. La universidad ha desarrollado varios programas de cooperación en varios niveles y muchas de ellos planteaban mostrar y experimentar con el fin de descubrir, propuesta en la que queremos ahondar y avanzar a través del patrimonio educativo

Differential proteomic analysis of the secretome of Irpex lacteus and other white-rot fungi during wheat straw pretreatment

BACKGROUND: Identifying new high-performance enzymes or enzyme complexes to enhance biomass degradation is the key for the development of cost-effective processes for ethanol production. Irpex lacteus is an efficient microorganism for wheat straw pretreatment, yielding easily hydrolysable products with high sugar content. Thus, this fungus was selected to investigate the enzymatic system involved in lignocellulose decay, and its secretome was compared to those from Phanerochaete chrysosporium and Pleurotus ostreatus which produced different degradation patterns when growing on wheat straw. Extracellular enzymes were analyzed through 2D-PAGE, nanoLC/MS-MS, and homology searches against public databases. RESULTS: In wheat straw, I. lacteus secreted proteases, dye-decolorizing and manganese-oxidizing peroxidases, and H(2)O(2) producing-enzymes but also a battery of cellulases and xylanases, excluding those implicated in cellulose and hemicellulose degradation to their monosaccharides, making these sugars poorly available for fungal consumption. In contrast, a significant increase of β-glucosidase production was observed when I. lacteus grew in liquid cultures. P. chrysosporium secreted more enzymes implicated in the total hydrolysis of the polysaccharides and P. ostreatus produced, in proportion, more oxidoreductases. CONCLUSION: The protein pattern secreted during I. lacteus growth in wheat straw plus the differences observed among the different secretomes, justify the fitness of I. lacteus for biopretreatment processes in 2G-ethanol production. Furthermore, all these data give insight into the biological degradation of lignocellulose and suggest new enzyme mixtures interesting for its efficient hydrolysis

Cardiorespiratory fitness cut-points are related to body adiposity parameters in Latin American adolescents

Background and Objectives: A deficiency exists in the criterion-referenced cut-points for field-based cardiorespiratory fitness (CRF) in Latin American youths. The aims of the present study were two-fold: (1) To identify the ability of CRF estimated by the 20-m shuttle-run test (20mSRT) to differentiate between 'healthy' and 'unhealthy' phenotypes (by adiposity) in adolescents; (2) to assess the association between obesity and relative peak oxygen uptake (VO2peak) in a large and diverse sample of Latin American youths. In total, 72,505 adolescents aged between 13 and 15 years were recruited from Chile and Colombia (47.5% girls). Materials and Methods: The waist circumference (WC) and waist-to-height ratio (WHtR) were used to identify body adiposity markers. CRF was measured using the 20mSRT (VO2peak). Receiver operating characteristic curves and logistic regression were used to determine the discriminatory ability of CRF to predict body adiposity parameters. Results: For boys and girls, VO2peak showed a significant predictive capacity to detect body fat (area under the curve [AUC] > 0.62). The sensitivity of VO2peak was medium (>63%) for all age- and sex-specific cut-points, with optimal cut-points in 13- to 15-year olds for obesity identified as 43.77 mL·kg-1·min-1 and 38.53 mL·kg-1·min-1 in boys and girls, respectively. Conclusions: According to these cut-points, adolescents with low CRF were more likely to be obese either by WC or WHtR. The CRF cut-points can be used as quantitative markers for a healthier body in Latin American adolescents.This study (Colombia sample) is supported by Secretaria de Educación Distrital-SED (ID Convenio N◦ CDP 3381, Project N◦ 893 'Pensar en Educación' date 02-Oct-2014). Mikel Izquierdo is funded in part by a research grant PI17/01814 of the Ministerio de Economía, Industria y Competitividad de España (ISCIII, FEDER)

2014 Ranking of journalistic innovation in Spain. Analysis and classification of 25 initiatives

The 201

Magnetic study of co-doped magnetosome chains

Magnetotactic bacteria synthesize a chain of magnetic nanoparticles, called magnetosome chain, used to align and swim along the geomagnetic field lines. In particular, Magnetospirillum gryphiswaldense biomineralize magnetite, Fe3O4. Growing this species in a Co-supplemented medium, Co-doped magnetite is obtained, tailoring in this way the magnetic properties of the magnetosome chain. Combining structural and magnetic techniques such as transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray absorption near edge structure, and X-ray magnetic circular dichroism, we determine that 1% of Co2+ substitutes Fe2+ located in octahedral places in the magnetite, thus increasing the coercive field. In the framework of the Stoner-Wohlfarth model, we have analyzed the evolution of the hysteresis loops as a function of temperature determining the different magnetic anisotropy contributions and their evolution with temperature. In contrast with the control magnetosome chains, whose effective anisotropy is uniaxial in the whole temperature range from 300 to 5 K, the effective anisotropy of Codoped magnetosome chains changes appreciably with temperature, from uniaxial down to 150 K, through biaxial down to 100 K, to triaxial below 100 K.L.M. acknowledges the Basque Government for her fellowship (PRE_2015_1_0130). We acknowledge the technical and human support provided by SGIker (UPV/EHU). Funding from the Spanish Government (project nos. MAT2014-55049-C2-R and MAT2017-83631-C3-R) and Basque Government (project n. IT711-13) is acknowledged. We thank the ESRF (CRG BM25 beamline-SpLine) and HZB for the allocation of synchrotron radiation beamtime and funding under the project CALIPSOplus (Grant Agreement 730872) from the EU Framework Programme for Research and Innovation HORIZON 2020. We thank R. Fernández-Pacheco for his assistance in the EDS measurements