1,775 research outputs found

    Stem Cells Derived from Neonatal Mouse Kidney Generate Functional Proximal Tubule-Like Cells and Integrate into Developing Nephrons In Vitro

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    We have recently shown that kidney-derived stem cells (KSCs) isolated from the mouse newborn kidney differentiate into a range of kidney-specific cell types. However, the functionality and integration capacity of these mouse KSCs remain unknown. Therefore, the main objectives of this study were (1) to determine if proximal tubule-like cells, generated in vitro from KSCs, displayed absorptive function typical of proximal tubule cells in vivo, and (2) to establish whether the ability of KSCs to integrate into developing nephrons was comparable with that of metanephric mesenchyme (MM), a transient population of progenitor cells that gives rise to the nephrons during kidney organogenesis. We found that proximal tubule-like cells generated in vitro from mouse KSCs displayed megalin-dependent absorptive function. Subsequently, we used a chimeric kidney rudiment culture system to show that the KSCs could generate proximal tubule cells and podocytes that were appropriately located within the developing nephrons. Finally, we compared the ability of KSCs to integrate into developing kidneys ex vivo with that of metanephric mesenchyme cells. We found that KSCs integrated into nascent nephrons to a similar extent as metanephric mesenchyme cells while both were excluded from ureteric bud branches. Our analysis of the behavior of the two cell types shows that some, but not all KSC characteristics are similar to those of the MM

    Análisis mediante elementos finitos de cargas de impacto sobre el irradiador de Cobalto 60 de la Escuela Politécnica Nacional del Ecuador.

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    En el presente trabajo se determinó el posible agrietamiento en los muros estructurales y efectos en el funcionamiento del Irradiador Gamma Panorámico Categoría IV con Fuente de Cobalto 60 que se encuentra en el interior del Edificio n.º 7 de la Escuela Politécnica Nacional (EPN), en Quito. El estudio consistió en analizar el impacto de una parte del techo que está sobre el irradiador de la instalación denominada “CASAMATA”, puesto que gracias a un estudio previo de esta estructura se demostró que es vulnerable debido a sus características, construcción y deterioro a lo largo del tiempo. El estudio se realizó en función de requisitos de normas de análisis y evaluación de estructuras existentes, mediante la utilización del software denominado “SAP2000” para la modelación del irradiador. Se realizaron seis modelaciones con diferentes características en cuanto a hormigón y acero de refuerzo para determinar el comportamiento de la estructura bajo los casos asumidos. De los resultados obtenidos mediante SAP2000 se observó que en algunos lugares del irradiador se tienen valores mayores a los máximos permitidos en el American Concrete Institute 349 (ACI 349), correspondientes a la deformación unitaria del hormigón el cual es de 0.003 m/m. Además, los requisitos de resistencia señalados en la misma norma, no cumplieron con los parámetros establecidos, lo cual provoca que exista un peligro radiológico debido a que la cámara de radiación no cumpliría con el blindaje para la cual fue diseñada y liberaría una tasa de dosis mínima de 1.13x106 [mSv/año]The present work determines the possible cracking in the structural walls and effects on the operation of the Category IV Panoramic Gamma Irradiator with Cobalt 60 Source, which is located inside Building No. 7 of the National Polytechnic School (EPN) in Quito. The analysis consisted of an alleged (supposed) impact of a roof section that is on the irradiator in the facility called “CASAMATA”, since a previous study of this structure showed that it is vulnerable due to its characteristics, construction, and deterioration throughout the time. The study was carried out based on the requirements of analysis and evaluation standards of existing structures by using the software called SAP2000 for modeling the irradiator. Six models with different characteristics in terms of concrete and reinforcing steel were made to determine the behavior of the structure under the assumed cases. From the results obtained through SAP2000, it was observed that in some places of the irradiator there are values greater than the maximum allowed in the American Concrete Institute 349 (ACI 349) corresponding to the unitary deformation of the concrete, which is 0.003 m/m. In addition, the resistance requirements indicated in the same standard did not meet the established parameters, which causes a radiological hazard because the radiation chamber would not comply with the shielding for which it was designed and would release a minimum dose rate of 1.13x106 [mSv/year]

    Reef fishes at all trophic levels respond positively to effective marine protected areas

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    Marine Protected Areas (MPAs) offer a unique opportunity to test the assumption that fishing pressure affects some trophic groups more than others. Removal of larger predators through fishing is often suggested to have positive flow-on effects for some lower trophic groups, in which case protection from fishing should result in suppression of lower trophic groups as predator populations recover. We tested this by assessing differences in the trophic structure of reef fish communities associated with 79 MPAs and open-access sites worldwide, using a standardised quantitative dataset on reef fish community structure. The biomass of all major trophic groups (higher carnivores, benthic carnivores, planktivores and herbivores) was significantly greater (by 40% - 200%) in effective no-take MPAs relative to fished open-access areas. This effect was most pronounced for individuals in large size classes, but with no size class of any trophic group showing signs of depressed biomass in MPAs, as predicted from higher predator abundance. Thus, greater biomass in effective MPAs implies that exploitation on shallow rocky and coral reefs negatively affects biomass of all fish trophic groups and size classes. These direct effects of fishing on trophic structure appear stronger than any top down effects on lower trophic levels that would be imposed by intact predator populations. We propose that exploitation affects fish assemblages at all trophic levels, and that local ecosystem function is generally modified by fishing

    Quantum Dots Do Not Affect the Behaviour of Mouse Embryonic Stem Cells and Kidney Stem Cells and Are Suitable for Short-Term Tracking

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    Quantum dots (QDs) are small nanocrystals widely used for labelling cells in order to enable cell tracking in complex environments in vitro, ex vivo and in vivo. They present many advantages over traditional fluorescent markers as they are resistant to photobleaching and have narrow emission spectra. Although QDs have been used effectively in cell tracking applications, their suitability has been questioned by reports showing they can affect stem cell behaviour and can be transferred to neighbouring cells. Using a variety of cellular and molecular biology techniques, we have investigated the effect of QDs on the proliferation and differentiation potential of two stem cell types: mouse embryonic stem cells and tissue-specific stem cells derived from mouse kidney. We have also tested if QDs released from living or dead cells can be taken up by neighbouring cells, and we have determined if QDs affect the degree of cell-cell fusion; this information is critical in order to assess the suitability of QDs for stem cell tracking. We show here that QDs have no effect on the viability, proliferation or differentiation potential of the two stem cell types. Furthermore, we show that the extent of transfer of QDs to neighbouring cells is <4%, and that QDs do not increase the degree of cell-cell fusion. However, although the QDs have a high labelling efficiency (>85%), they are rapidly depleted from both stem cell populations. Taken together, our results suggest that QDs are effective cell labelling probes that are suitable for short-term stem cell tracking

    Technological Development of CNC Machine Tool for Machining Soft Materials

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    In recent years, the process carried out in the GACIPE research group is related to the development of the base technology of the manufacturing and metalworking industry. The machine tools that are vital for the consolidation and competitiveness of the industry in any country has been approached through two approaches: The design and construction of the new machine. In this aspect, the modeling of the structure and the displacements’ parameterization allows defining the precision of the movements and the rational use of energy. The adaptation and repowering of a used machine. In this approach, the recovery and technological updating proposed to recover its performance, becoming an excellent alternative to improving and perfecting the production of a company. In both cases, the CNC milling machine tools are controlled by free software. The application proposed is mechanized in soft materials

    La Cátedra de Rolando García de humanismo, interdisciplina y complejidad del CEG-UNA

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    Se presenta el proyecto de la Cátedra Rolando García de Humanismo, Interdisciplina y Complejidad (CRG) del Centro de Estudios Generales (CEG) de la Universidad Nacional (UNA), para el período 2015-2020. El objetivo de esta publicación es avanzar en la elaboración de un marco conceptual y metodológico para la implementación práctica del trabajo interdisciplinario en el CEG. Se presentan los antecedentes (marco conceptual preliminar) en los que se fundamenta el objetivo, los alcances y el plan de trabajo de la cátedra, así como las etapas y la metodología de trabajo en equipo conducente a la materialización de una serie de productos que servirán de plataforma de lanzamiento del trabajo interdisciplinario en el CEG. La Cátedra Rolando García de humanismo, interdisciplina y complejidad busca gestar un espacio de investigación, reflexión, debate, producción y extensión, que durante tres años desarrolle las bases conceptuales y metodológicas y una hoja de ruta, para la profundización del Nuevo Humanismo en tanto paradigma transdisciplinario, así como del desarrollo práctico de la interdisciplina en las cuatro áreas de la acción sustantiva principales del quehacer académico de la UNA: docencia, investigación, extensión y producción. Para ello la Cátedra está concebida como un foro abierto, plural y participativo

    Global human footprint on the linkage between biodiversity and ecosystem functioning in reef fishes

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    Copyright: © 2011 Mora et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Difficulties in scaling up theoretical and experimental results have raised controversy over the consequences of biodiversity loss for the functioning of natural ecosystems. Using a global survey of reef fish assemblages, we show that in contrast to previous theoretical and experimental studies, ecosystem functioning (as measured by standing biomass) scales in a non-saturating manner with biodiversity (as measured by species and functional richness) in this ecosystem. Our field study also shows a significant and negative interaction between human population density and biodiversity on ecosystem functioning (i.e., for the same human density there were larger reductions in standing biomass at more diverse reefs). Human effects were found to be related to fishing, coastal development, and land use stressors, and currently affect over 75% of the world's coral reefs. Our results indicate that the consequences of biodiversity loss in coral reefs have been considerably underestimated based on existing knowledge and that reef fish assemblages, particularly the most diverse, are greatly vulnerable to the expansion and intensity of anthropogenic stressors in coastal areas

    Long-acting injectable Cabotegravir + Rilpivirine for HIV maintenance therapy: Week 48 pooled analysis of phase 3 ATLAS and FLAIR trials

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    BACKGROUND: Long-acting (LA) injectable regimens are a potential therapeutic option in people living with HIV-1. SETTING: ATLAS (NCT02951052) and FLAIR (NCT02938520) were 2 randomized, open-label, multicenter, multinational phase 3 studies. METHODS: Adult participants with virologic suppression (plasma HIV-1 RNA &lt;50 copies/mL) were randomized (1:1) to continue with their current antiretroviral regimen (CAR) or switch to the long-acting (LA) regimen of cabotegravir (CAB) and rilpivirine (RPV). In the LA arm, participants initially received oral CAB + RPV once-daily for 4 weeks to assess individual safety and tolerability, before starting monthly injectable therapy. The primary endpoint of this combined analysis was antiviral efficacy at week 48 (FDA Snapshot algorithm: noninferiority margin of 4% for HIV-1 RNA ≥50 copies/mL). Safety, tolerability, and confirmed virologic failure (2 consecutive plasma HIV-1 RNA ≥200 copies/mL) were secondary endpoints. RESULTS: The pooled intention-to-treat exposed population included 591 participants in each arm [28% women (sex at birth), 19% aged ≥50 years]. Noninferiority criteria at week 48 were met for the primary (HIV-1 RNA ≥50 copies/mL) and key secondary (HIV-1 RNA &lt;50 copies/mL) efficacy endpoints. Seven individuals in each arm (1.2%) developed confirmed virologic failure; 6/7 (LA) and 3/7 (CAR) had resistance-associated mutations. Most LA recipients (83%) experienced injection site reactions, which decreased in incidence over time. Injection site reactions led to the withdrawal of 6 (1%) participants. The serious adverse event rate was 4% in each arm. CONCLUSION: This combined analysis demonstrates monthly injections of CAB + RPV LA were noninferior to daily oral CAR for maintaining HIV-1 suppression

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Clinical practice guideline for surgical antimicrobial prophylaxis

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    La infección del sitio quirúrgico (ISQ) es una de las principales causas de infecciones asociadas a la atención en salud (IAAS), con un impacto significativo en la mortalidad y morbilidad del paciente quirúrgico, así como en los costos asociados a la atención en salud. El adecuado uso de la profilaxis quirúrgica antimicrobiana es un aspecto fundamental en la reducción del riesgo de ISQ, dado que su utilización inapropiada o indiscriminada puede representar un riesgo para los pacientes y contribuir al desarrollo de resistencia a los antimicrobianos, por lo que resulta de importancia generar directrices que permitan orientar el uso adecuado de antimicrobianos en la profilaxis del paciente quirúrgico, con el objetivo de obtener mejores desenlaces clínicos y propender por un uso racional de antibióticos. La presente guía contiene recomendaciones para profilaxis antibiótica de pacientes sometidos a procedimiento quirúrgico, basadas en la evidencia, realizadas mediante el proceso de adaptación de guías de práctica clínica para el contexto colombiano.Q4Pacientes sometidos a Profilaxis quirúrgica antimicrobianaSurgical site infection (SSI) is one of the main causes of healthcare associated infections (HAI), with a significant impact on the mortality and morbidity of the surgi-cal patient, as well as on the costs associated with health care. The adequate use of surgical antimicrobial prophylaxis being a fundamental aspect in reducing the risk of SSI, taking into account that the inappropriate or indiscriminate use of antibiotics in surgical prophylaxis may represent a risk for patients and contribute to the development of antimicrobial resistance, so it is important to generate guidelines that guide the appropriate antimicrobial prophylaxis in the surgical patient, with the aim of obtaining better clinical outcomes and promoting a rational use of antibiotics. This guide contains recommendations for antibiotic prophylaxis in patients undergoing a surgical procedure, based on evidence, carried out through the process of adapting clinical practice guidelines for the Colombian context.https://orcid.org/0000-0002-5392-7083https://orcid.org/0000-0003-2568-4667Revista Nacional - IndexadaCN
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