Self-assembly of supramolecular chemoenzymatic poly-l-phenylalanine

The self-assembly behavior of chemoenzymatic high molecular weight (ca. 30 000 Da) poly-L-phenylalanine (ePLP) and the nano-morphologies thereof are investigated. Interestingly, this supramolecular ePLP changes from a non-ordered secondary structure when solubilized in water to an a-helix with the addition of only 1 vol% HFIP co-solvent, and at a relatively low concentration (0.5 mg mL-1). The results also indicate a temperature-dependent structural stabilization, wherein the self-assembly process is mainly governed by hydrogen bonding. The analyses evidence self-assembly under controlled conditions to obtain nanotubes with an average diameter of 0.21 ± 0.04 µm, and above 100 µm length. Microbeam synchrotron radiation infrared (SRIR) spectroscopy demonstrates parallel orientations of the amide moieties in the a-helical structure, which is extraordinary for this long chain ePLP. The achievement of these highly homogeneous nanotubes is relevant since previous reports only demonstrated this arrangement for end-capped F-moc-containing short oligophenylalanines. In the same way, the conductivity behaviors of the nanotubular structure remained unchanged in the range of 273–313 K demonstrating its stability from hydrogen bonds, and also, direct dielectric measurements reveal a high orientation and stabilization by intra- and intermolecular hydrogen bonds in the nanotubes. These characteristics allow drug delivery assays with tetracycline-loaded nanotubes and further applications are envisaged.Peer ReviewedPostprint (author's final draft

Territorios y experiencias literarias: el proyecto de extensión “Literatura en los Márgenes” del IFDC Bariloche

Este artículo da cuenta de la experiencia que desde 2012 viene llevando a cabo el Proyecto de Extensión a la Comunidad “Literatura en los Márgenes” del Instituto de Formación Docente Continua de Bariloche. Conformado por estudiantes (de los profesorados de Educación Primaria y Especial de este Instituto y de otras instituciones) y docentes (del propio IFDC y de escuelas primarias), el proyecto se ha constituido en un ámbito privilegiado de formación inicial, extensión y capacitación, además de un lugar de experimentación y  construcción de un saber específico sobre los modos de participación en torno a la palabra literaria en espacios diversos. Se recuperan, además, el rico historial de intervenciones en ámbitos diversos  (sobre todo a través del Grupo de Susurradoras y de una diversidad de talleres) y los viajes de estudio realizados

Mitochondrial Na+ controls oxidative phosphorylation and hypoxic redox signalling

All metazoans depend on O2 delivery and consumption by the mitochondrial oxidative phosphorylation (OXPHOS) system to produce energy. A decrease in O2 availability (hypoxia) leads to profound metabolic rewiring. In addition, OXPHOS uses O2 to produce reactive oxygen species (ROS) that can drive cell adaptations through redox signalling, but also trigger cell damage1–4, and both phenomena occur in hypoxia4–8. However, the precise mechanism by which acute hypoxia triggers mitochondrial ROS production is still unknown. Ca2+ is one of the best known examples of an ion acting as a second messenger9, yet the role ascribed to Na+ is to serve as a mere mediator of membrane potential and collaborating in ion transport10. Here we show that Na+ acts as a second messenger regulating OXPHOS function and ROS production by modulating fluidity of the inner mitochondrial membrane (IMM). We found that a conformational shift in mitochondrial complex I during acute hypoxia11 drives the acidification of the matrix and solubilization of calcium phosphate precipitates. The concomitant increase in matrix free-Ca2+ activates the mitochondrial Na+/Ca2+ exchanger (NCLX), which imports Na+ into the matrix. Na+ interacts with phospholipids reducing IMM fluidity and mobility of free ubiquinone between complex II and complex III, but not inside supercomplexes. As a consequence, superoxide is produced at complex III, generating a redox signal. Inhibition of mitochondrial Na+ import through NCLX is sufficient to block this pathway, preventing adaptation to hypoxia. These results reveal that Na+ import into the mitochondrial matrix controls OXPHOS function and redox signalling through an unexpected interaction with phospholipids, with profound consequences in cellular metabolism

Comportamientos, problemas y avances

Libro electrónicoNo obstante los empeños emprendidos por muchos de los estudiosos del turismo en Latinoamérica, se destaca que una de las limitaciones más enfáticamente reiteradas sobre el quehacer científico es la escasa conjunción de esfuerzos para potencializar y difundir sus investigaciones sobre las problemáticas sociales, culturales, ambientales, económicas y políticas que presenta el turismo en la región (Osorio, 2016; Pearce, 2013). Esta exigua coordinación y trabajo en red de los académicos latinoamericanos ha inhibido la construcción de una sinergia colaborativa que visibilice y comparta los conocimientos entorno a una región geográfica con retos comunes. Justo con la intención de contribuir a superar esta limitante, se integra la presente obra, cuyo propósito radica en conjuntar distintos casos de estudio sobre la planificación y gestión del turismo en México, Chile, Argentina y Brasil, como una muestra indicativa de los objetos de estudio, los marcos teórico-metodológicos y las aportaciones de conocimiento que se están desarrollando en la región, para con ello desvelar su contribución al estado del arte de los estudios espaciales del turismo.Colección PASOS Edita Academia Mexicana de Investigación Turística Universidad del Carib

Guía Mexicana para el Diagnóstico y el Tratamiento de la Urticaria

La urticaria es una enfermedad que padece una quinta parte de la población en algún momento de su vida. Las guías inter- nacionales recientes han propuesto unos cambios de fondo en su diagnóstico y tratamiento, por lo que había la necesidad de crear una guía nacional y multidisciplinaria, con base amplia en los gremios de especialistas y médicos de primer contacto en México. ABSTRACT Urticaria is a disease that a fifth of the population shall suffer once in a lifetime. Recent clinical guidelines have proposed some fundamental changes in the diagnosis and treatment of urticaria, making the development of a national, multidisciplinary guideline, with wide acceptability among different professional groups –both specialists and primary health care workers–, necessary in Mexico

Resultados Semilleros de Investigación 2009-2010

La publicación recoge los doce informes finales de investigación presentados por los estudiantes de ocho Semilleros 1 y cuatro Semilleros 2, correspondientes a la convocatoria 2009–2010 y se constituye en el Número 25 de la Serie de Investigaciones en Construcción, si bien este es el primer Número publicado en formato digital que UNIJUS se permite poner a disposición no sólo de la comunidad universitaria, sino también de la sociedad colombiana e internacional, interesada en los temas estudiados por los jóvenes investigadores de la Facultad de Derecho, Ciencias Políticas y Sociales de la Universidad Nacional de Colombia

Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 11

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 11, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR), Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTAG), Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kleber Ramírez (UPTM), Mérida – Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (C.A.B.B.O.P.P), Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE), Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia - Venezuela, Centro de Investigaciones Internacionales SAS (CIN), Antioquia - Colombia.y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Biopolymeric Fibrous Aerogels: The Sustainable Alternative for Water Remediation

The increment in water pollution due to the massive development in the industrial sector is a worldwide concern due to its impact on the environment and human health. Therefore, the development of new and sustainable alternatives for water remediation is needed. In this context, aerogels present high porosity, low density, and a remarkable adsorption capacity, making them candidates for remediation applications demonstrating high efficiency in removing pollutants from the air, soil, and water. Specifically, polymer-based aerogels could be modified in their high surface area to integrate functional groups, decrease their hydrophilicity, or increase their lipophilicity, among other variations, expanding and enhancing their efficiency as adsorbents for the removal of various pollutants in water. The aerogels based on natural polymers such as cellulose, chitosan, or alginate processed by different techniques presented high adsorption capacities, efficacy in oil/water separation and dye removal, and excellent recyclability after several cycles. Although there are different reviews based on aerogels, this work gives an overview of just the natural biopolymers employed to elaborate aerogels as an eco-friendly and renewable alternative. In addition, here we show the synthesis methods and applications in water cleaning from pollutants such as dyes, oil, and pharmaceuticals, providing novel information for the future development of biopolymeric-based aerogel