Análisis comparativo del uso de nanosílice y ceniza volante en el concreto hidráulico

Context: Nowadays, nanomaterials constitute an innovative alternative for the construction sector. This study evaluates the benefits of adding nanosilica and fly ash to Portland cement concrete in terms of its mechanical strength properties. Methodology: 45 specimens were used to compare the compressive strength and durability of concrete mixtures with nanosilica and fly ash. The specimens were studied after 7, 14, and 21 days to determine their maximum resistance. Results: The addition of small amounts of nanosilica (up to 1%) significantly improved the compressive strength of the concrete. In contrast, a large amount of fly ash (up to 8%) was required for a noticeable effect. Conclusions: Concrete with nanosilica yielded the best results in terms of mechanical strength. The key to improving concrete through nanosilica and fly ash is to reduce the water-to-cement ratio using chemical agents that reduce porosity and increase resistance.Contexto: Hoy en día, los nanomateriales representan una alternativa innovadora para el sector de la construcción. Este estudio evalúa los beneficios de añadir nanosílice y ceniza volante al concreto de cemento Portland en función de sus propiedades de su resistencia mecánica. Método: Se utilizaron 45 especímenes para comparar la resistencia a la compresión y la durabilidad de mezclas de concreto con nanosílice y ceniza volante. Los especímenes fueron estudiados a los 7, 14 y 21 días para determinar su máxima resistencia. Resultados: La adición de cantidades pequeñas de nanosílice (hasta 1 %) mejoraron significativamente la resistencia a la compresión del concreto. En contrate, se necesitó una gran cantidad de ceniza volante (hasta 8 %) para lograr un efecto notable. Conclusiones: El concreto con nanosílice dio los mejores resultados en cuanto a resistencia mecánica. La clave para mejorar el concreto con nanosílice y ceniza volante es reducir la relación cemento-agua utilizando agentes químicos que reduzcan la porosidad y aumenten la resistencia

Hacia una formación docente en la práctica del diseño concientizado y su metodología

El pensamiento concientizado encuentra significación en la ardua tarea del diseñador industrial y ¿Por qué no? de todo tipo de diseñadores encargados de transformar al mundo con conceptos y formas que ayudan a comunicarse entre sí, tarea que cada vez exige un pensamiento renovado y ético sobre los usos de recursos naturales y sus procesos muy cercanos a la sustentabilidad, recursos que de alguna manera están desapareciendo, por lo menos como se conocen en el planeta y que lleva a una extinción fulminante y anunciada

Risk Factors and Predictive Score for Bacteremic Biliary Tract Infections Due to Enterococcus faecalis and Enterococcus faecium: a Multicenter Cohort Study from the PROBAC Project

Biliary-tract bloodstream infections (BT-BSI) caused by Enterococcus faecalis and E. faecium are associated with inappropriate empirical treatment and worse outcomes compared to other etiologies. The objective of this study was to investigate the risk factors for enterococcal BT-BSI. Patients with BT-BSI from the PROBAC cohort, including consecutive patients with BSI in 26 Spanish hospitals between October 2016 and March 2017, were selected; episodes caused by E. faecalis or E. faecium and other causes were compared. Independent predictors for enterococci were identified by logistic regression, and a predictive score was developed. Eight hundred fifty episodes of BT-BSI were included; 73 (8.5%) were due to target Enterococcus spp. (48 [66%] were E. faecium and 25 [34%] E. faecalis). By multivariate analysis, the variables independently associated with Enterococcus spp. were (OR; 95% confidence interval): cholangiocarcinoma (4.48;1.32 to 15.25), hospital acquisition (3.58;2.11 to 6.07), use of carbapenems in the previous month (3.35;1.45 to 7.78), biliary prosthesis (2.19;1.24 to 3.90), and moderate or severe chronic kidney disease (1.55;1.07 to 2.26). The AUC of the model was 0.74 [95% CI0.67 to 0.80]. A score was developed, with 7, 6, 5, 4, and 2 points for these variables, respectively, with a negative predictive value of 95% for a score # 6. A model, including cholangiocarcinoma, biliary prosthesis, hospital acquisition, previous carbapenems, and chronic kidney disease showed moderate prediction ability for enterococcal BT-BSI. Although the score will need to be validated, this information may be useful for deciding empirical therapy in biliary tract infections when bacteremia is suspected. IMPORTANCE Biliary tract infections are frequent, and a significant cause of morbidity and mortality. Bacteremia is common in these infections, particularly in the elderly and patients with cancer. Inappropriate empirical treatment has been associated with increased risk of mortality in bacteremic cholangitis, and the probability of receiving inactive empirical treatment is higher in episodes caused by enterococci. This is because many of the antimicrobial agents recommended in guidelines for biliary tract infections lack activity against these organisms. To the best of our knowledge, this is the first study analyzing the predictive factors for enterococcal BT-BSI and deriving a predictive score.8 página

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Caminando en la ruta sentipensante: configuración de experiencias pedagógicas nivel inicial

494 páginasEste texto es realizado en el contexto del Plan de Desarrollo 2016 – 2020, “Bogotá mejor para todos”, en el que se señala: Bogotá es entendida como una ciudad educadora, en la que todos los ciudadanos son agentes educadores y todos los espacios pueden ser escenarios pedagógicos para el aprendizaje. Una ciudad educadora tiene como centro el conocimiento e inspira aprendizaje, formas y lenguajes para reconocernos, para reencontrarnos; los espacios para el aprendizaje son entendidos como espacios para la vida, en los que se posibilita la investigación y la innovación para vivir mejor, para reinventarnos como ciudad, una ciudad mejor para todos. Los dieciocho textos aquí presentados, fruto del acompañamiento pedagógico realizado por el IDEP en 2019, son base y referente para seguir aportando en la configuración y consolidación de comunidades de saber y práctica pedagógica de la ciudad, así como en la conformación de colectivos y redes de maestros. Son la evidencia de un potente trabajo de acompañamiento a experiencias de nivel inicial, caracterizadas por contar con ideas o avances para problematizar, estructurar, fundamentar, elaborar estrategias y un plan de acción

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p &lt; 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics

Prácticas de gestión tecnológica en la industria de la construcción: el caso de una empresa pública de ingeniería civil

In order to grow, today’s companies have to develop new and better products or services. One way to accomplish this task is through technology management. In Mexico, there is a National Award given to those organizations that have become more competitive by means of an efficient management system.Private businesses operating in the telecommunication, electrodomestic and pharmaceutical sectors have won such a prize. However, public institutions and more particularly those in the construction industry have not received it. In an effort to determine the current level of use and importance of the perception of “best practices” for technology management in a governmental organization involved in civil engineering activities, research was carried out.The results revealed that there is still room for improvement in this sector.En la actualidad, las empresas que quieren crecer tienen que desarrollar nuevos y mejores productos o servicios. Una forma de lograrlo es a través de la gestión tecnológica. En México existe un premio nacional que se otorga a las compañías que cuentan con sistemas eficientes de gestión que las hacen ser más competitivas. Dicho galardón lo han ganado organizaciones privadas en diversos sectores como los de telecomunicaciones, electrodomésticos y farmacéuticos. Sin embargo, las instituciones públicas y en particular las de la industria de la construcción no han recibido esa distinción. En un esfuerzo por determinar los niveles de uso y de importancia percibida de las “mejores prácticas” de gestión tecnológica en una empresa del gobierno dedicada a la ingeniería civil, se llevó a cabo una investigación. Los resultados revelan que aún existen oportunidades de mejora en el sector

Prácticas de gestión tecnológica en la industria de la construcción: el caso de una empresa pública de ingeniería civil

En la actualidad, las empresas que quieren crecer tienen que desarrollar nuevos y mejores productos o servicios. Una forma de lograrlo es a través de la gestión tecnológica. En México existe un premio nacional que se otorga a las compañías que cuentan con sistemas eficientes de gestión que las hacen ser más competitivas. Dicho galardón lo han ganado organizaciones privadas en diversos sectores como los de telecomunicaciones, electrodomésticos y farmacéuticos. Sin embargo, las instituciones públicas y en particular las de la industria de la construcción no han recibido esa distinción. En un esfuerzo por determinar los niveles de uso y de importancia percibida de las mejores prácticas de gestión tecnológica en una empresa del gobierno dedicada a la ingeniería civil, se llevó a cabo una investigación. Los resultados revelan que aún existen oportunidades de mejora en el secto