267 research outputs found

    Emerging Biofabrication Techniques: A Review on Natural Polymers for Biomedical Applications

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    Natural polymers have been widely used for biomedical applications in recent decades. They offer the advantages of resembling the extracellular matrix of native tissues and retaining biochemical cues and properties necessary to enhance their biocompatibility, so they usually improve the cellular attachment and behavior and avoid immunological reactions. Moreover, they offer a rapid degradability through natural enzymatic or chemical processes. However, natural polymers present poor mechanical strength, which frequently makes the manipulation processes difficult. Recent advances in biofabrication, 3D printing, microfluidics, and cell-electrospinning allow the manufacturing of complex natural polymer matrixes with biophysical and structural properties similar to those of the extracellular matrix. In addition, these techniques offer the possibility of incorporating different cell lines into the fabrication process, a revolutionary strategy broadly explored in recent years to produce cell-laden scaffolds that can better mimic the properties of functional tissues. In this review, the use of 3D printing, microfluidics, and electrospinning approaches has been extensively investigated for the biofabrication of naturally derived polymer scaffolds with encapsulated cells intended for biomedical applications (e.g., cell therapies, bone and dental grafts, cardiovascular or musculoskeletal tissue regeneration, and wound healing)

    Alkaline cement mortars. Chemical resistance to sulfate and seawater attack

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    The durability and chemical resistance of alkali activated slag and fly ash/slag mortars in contact with sulfates and seawater media have been studied. Two methods were used in the evaluation of such durability: Kock-Steinegger and ASTM CI012. A mineralogical and a microstructural characterization of mortars were done at different ages of their conservation in aggressive media through XRD, SEM/EDX and mercury porosimetry. Results showed a high durability of activated cement mortars in sulfates and seawater media. NaOH activated mortars are the most sensitive to environment attack with formation of expansive products as gypsum and ettringite, although in very low proportion.Se ha estudiado la estabilidad química en medios sulfáticos y de agua de mar de morteros de escorias activadas alcalinamente y morteros de mezclas de escoria y cenizas volantes activadas alcalinamente. Se han empleado dos métodos para evaluar dicha estabilidad: Kock-Steinegger y la norma ASTM CIO 12. Se ha realizado una caracterización mineralógica y micro estructural de los morteros (a diferentes edades de permanencia en los medios agresivos) a través de DRX, SEM/EDXy porosimetría de mercurio. Los resultados obtenidos han demostrado la elevada durabilidad de todos los morteros de cementos activados estudiados frente a la agresividad de los sulfatos y del agua de mar Los morteros de escoria activada con NaOH son los más susceptibles al ataque por esos medios, conformación de productos expansivos como el yeso y la etringita, aunque en proporciones muy bajas.Consejo Superior de investigaciones Cientificas (CSIC)Peer reviewe

    The mediation police in family and couple conflict: analysis of the agreements

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    La mediación es una alternativa, cada vez más implantada, para la resolución de conflictos fuera del ámbito judicial y una de sus aplicaciones en los conflictos denunciados ante la policía. El presente trabajo parte de una experiencia de la mediación policial que se ha llevado un cabo durante los años 2012-2014. Dos técnicas de obtención de datos han sido aplicadas: por un lado en el análisis de los expedientes, con todo el conjunto de variables que pueden ser aplicables; y por otro realizando cuestionarios a las partes implicadas. Las dos condiciones adoptadas como criterio en la selección de casos: que se refieren a conflictos familiares de pareja y que se registraron en un acuerdo de resolución. Con estos datos, el análisis incide, más allá de las características, en la satisfacción del proceso y la permanencia del conflicto. Entre las conclusiones destaca la incidencia de las variables sociodemográficas, especialmente el nivel de estudios y ocupacional y el grado alto de satisfacción y recomendación del servicio. No obstante, existe un elevado porcentaje de repetición de conflictos, especialmente en los casos de conflictos familiar.Mediation is an alternative, increasingly implemented, for the resolution of conflicts outside the judicial sphere and one of its applications in conflicts reported to the police. The present work is part of an experience of police mediation that has been carried out during the years 2012-2014. Two data collection techniques have been applied: on the one hand, in the analysis of the files, with the whole set of variables that may be applicable; And by performing questionnaires to the parties involved. The two conditions adopted as a criterion in the selection of cases that refer to family conflicts of partners and which were registered in a resolution agreement. With these data, the analysis affects, beyond the characteristics, in the satisfaction of the process and the permanence of the conflict. As conclusions, the incidence of sociodemographic variables, especially the level of studies and occupational and the high degree of satisfaction and recommendation of the service, stands out. However, there is a high rate of repetition of conflicts, especially in cases of family conflicts

    Supramolecular Structure and Renaturation of a (1→3)-β-D-Glucan Compared with Curdlan and Scleroglucan

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    A (1→3)-β-D-Glucan produced by Lactobacillus suebicus CUPV221 strain was investigated by tapping mode atomic force microscopy (TM-AFM), to compare its supramolecular structure and conformation with two commercial polysaccharides: curdlan and scleroglucan. It was found that the β-D-Glucan was a (1→3)(1→2)-β-D-Glucan and at room temperature formed three-dimensional networks by entanglements between strands, as does scleroglucan. However, (1→3)(1→2)-β-D-Glucan strands seemed to be more stiff than those of scleroglucan. It was also observed that curdlan samples deposited from 5 mM NaOH aqueous solution showed supermolecular assemblies, recognized in the literature as micelles, which are controlled by hydrophobic hydration. The (1→3)(1→2)-β-D-Glucan in alkaline aqueous solutions produced different supramolecular structures depending on pH, and at 0.4 M NaOH (pH 13.16), denaturation took place. After neutralizing the alkaline solution with HCl, the formation of short linear, circular, and hairpin structures was observed.This study was supported by grants AGL2009-12998-C03 and AGL2012-40084 from the Spanish Ministry of Science and Innovation, and IT335-10 from the Basque Government. Ana Isabel Puertas acknowledges the “Gobierno Vasco, Dpto. Agricultura, Pesca y Alimentación” for the fellowship

    Identification of miRNAs involved in foetal growth restriction due to maternal smoking during pregnancy

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    Introduction: Smoking during pregnancy is associated with reduced foetal growth, amongst other effects. Epigenetic modification in the foetus and placenta during embryonic development as a result of changes in the function of miRNAs is one of the pathophysiological mechanisms responsible for this. This dysregulation may be due to environmental changes or toxins such as tobacco. Objective: To study the impact of smoking during pregnancy and its role in intrauterine growth restriction via hypermethylated miRNAs. Materials and methods: The differences in methylation patterns for miRNAs in umbilical cord blood from low-birth-weight newborns of smoking mothers were compared with those from normal-weight newborns using MedIP-seq (StarArray). Results: Seven hypermethylated miRNAs were identified in the epigenetic study of cord blood from low-birth-weight newborns of smoking mothers in our sample. The miRNAs found to be hypermethylated were: MIR7-1, MIR3918, MIR1244-1, MIR4721, MIR25, MIR93, MIR3656. Conclusion: Intrauterine exposure to tobacco induces hypermethylation-mediated miRNA silencing in low-birth-weight newborns by modifying the expression of factors involved in vascular development, growth, and adaptation to hypoxia

    Pool-Type Fishway Design for a Potamodromous Cyprinid in the Iberian Peninsula: The Iberian Barbel—Synthesis and Future Directions

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    M.B., J.R.R., and J.P. would like to acknowledge support from the Spanish Ministry of Economy and Competitiveness (Ministerio de Economía y Competitividad) (Ref. CGL2012-34688) and thank the CITEEC (Centro de Innovación Tecnolóxica en Edificación e Enxeñería Civil) of the University of A Coruña and the Center for Hydrographic Studies of CEDEX for their ongoing collaboration in this research field. Finally, the authors want to thank the three anonymous reviewers for their comments and suggestions that improved this manuscript.The Iberian barbel (Luciobarbus bocagei) is one of the most common cyprinids in the Iberian Peninsula, whose migratory routes are often hampered by anthropogenic barriers. Fishways might be an effective mitigation measure if they integrate designed operational characteristics that account for the biomechanical requirements of this species. Understanding the flow conditions inside the fishway, and how barbel responds to the hydrodynamics of the flow is imperative to improve free migratory routes with minimum energetic cost associated. Herein, we analyze and synthesize the main findings of research on pool-type fishways for upstream passage of the Iberian barbel and derive recommendations of design criteria for pool-type fishways for this species and others of similar biomechanics capacities. Ultimately, we identify research needs to improve upstream passage of this species.A.T.S. was supported by the Norwegian Research Centre for Hydropower Technology—HydroCen (Project No. 257588); M.B. was funded from EU’s Horizon 2020 Programme under Marie Sklodowska-Curie Grant Agreement 754446 and UGR Research and Knowledge Transfer Fund—Athenea3i; and J.M.S. was supported by national funds via FCT under the CEEC Institucional 2018 (Ref. 2/ISA/FCT/2018). Forest Research Centre (CEF) is a research unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal (UIDB/00239/2020)

    Editorial: Women in plant science:redox biology of plant abiotic stress 2022

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    MR-P thanks Spanish Ministry of Science and Innovation for Financial support (PID2021-122280NB-I00). CF thanks BBSRC/GCRF (UK) for Financial support (BB/T008865/1). LG thanks Agritech National Research Center (European Union Next-Generation, EU), Piano Nazionale di Ripresa e Resilienza (PNRR) —Missione 4 Componente 2, Investimento 1.4—D.D. 1032 17/06/ 2022, CN00000022)

    The cell division protein FtsZ from Streptococcus pneumoniae exhibits a GTPase activity delay

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    © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.. The cell division protein FtsZ assembles in vitro by a mechanism of cooperative association dependent on GTP, monovalent cations, and Mg2+. We have analyzed the GTPase activity and assembly dynamics of Streptococcus pneumoniae FtsZ (Spn-FtsZ). SpnFtsZ assembled in an apparently cooperative process, with a higher critical concentration than values reported for other FtsZ proteins. It sedimented in the presence of GTP as a high molecular mass polymer with a well defined size and tended to form double-stranded filaments in electron microscope preparations. GTPase activity depended on K+ and Mg2+ and was inhibited by Na+. GTP hydrolysis exhibited a delay that included a lag phase followed by a GTP hydrolysis activation step, until reaction reached the GTPase rate. The lag phase was not found in polymer assembly, suggesting a transition from an initial non-GTP-hydrolyzing polymer that switches to a GTP-hydrolyzing polymer, supporting models that explain FtsZ polymer cooperativity.Spanish Government GrantsBIO2011-28941-C03 (to G. R. and C. A.) and BIO2011-28941-C01; Torres Quevedo Program Grant PTQ-11-05049 to Biomol Informatics S.L.Peer Reviewe

    Química de los cementos

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    En la presente comunicación se describen los resultados mas relevantes obtenidos a lo largo del tiempo en torno a algunas de las líneas de trabajo mas importantes que se desarrollan en el seno del grupo de investigación “Química del Cemento” del Instituto de Ciencias de la Construcción Eduardo Torroja (IETcc-CSIC).Edición financiada por el Ministerio de Educación y Ciencia con cargo al "Plan Nacional de I+D+I 2004-2007".Peer reviewe
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