Search

Desde el momento mismo en que se fue construyendo la función magisterial, esta ha sufrido trasformaciones, que han implicado un cambio en la forma como la ciudadanía la reconoce, haciendo que esta se disperse en multiplicidad de discursos, que a la vez que resignifican el oficio como profesional de la educación, hace que esta tenga otras variables que no lo que se las que corresponden propiamente a su ser formador, como lo se ha entendido tradicionalmente y se le ha identificado en ese “deber ser” que nos plantea la sociedad. Si toda sociedad define el sujeto que desea tener, determinando los elementos y las normas que lo ordenan como un conjunto pleno de significados, aquí buscamos centrar nuestra mirada en las maneras de ser maestro, a través de las prácticas escolares y de las formas como ha sido concebido en algunos documentos oficiales, que son una respuesta que incide en la transformación de las políticas educativas colombianas. Es así que la decisión de “mirar de otro modo” la realidad educativa anima a analizar los dispositivos de formación docente, para buscar en ellos o sus bordes e intersticios aquello que podría estar favoreciendo u obstaculizando la autoformación y la construcción de un ethos (carácter manera de ser) profesional del docente.

ABSTRACT BACKGROUND: Colon cancer is the third most common malignancy in Colombia, only exceeded by prostate and breast cancers. It is the second most common cancer among females and the third most common among males. The epidemiology of this disease has changed in Colombia, and its peak incidence has now surpassed that of gastric cancer. AIMS: We aimed to determine the association between hospital surgical volume and mortality in patients with colon cancer undergoing surgical resection in Colombia. METHODS: This was a national retrospective cohort study based on administrative data and included adult patients undergoing surgical resection for colon cancer who were enrolled in Colombia’s contributory health system between 2012 and 2017. We defined exposure as the hospital’s surgical volume where the colon cancer surgery was performed. We classified the patients as exposed to a high surgical volume (above the 90th percentile of the provider distribution) and a low surgical volume (under the 90th percentile). The main outcomes were 30-day and 1-year mortality. Multivariate Poisson regressions were used to identify the association between exposure and mortality rates. RESULTS: The study included 4,647 patients, of which 4,188 underwent surgery at hospitals with a colectomy volume lower than 33 per year and 459 underwent surgery at institutions with volumes equal to or higher than 33 per year. In the multivariate analysis, after adjusting for observable variables, a lower risk of 30-day mortality was found in patients who underwent surgery at high surgical volume institutions (relative risk - RR 0.57, 95% confidence interval - 95%CI 0.033-0.97). No differences were found in the one-year mortality. CONCLUSION: The high surgical volume of a hospital is associated with a 30-day mortality in colon cancer, as described in other studies, but the 1-year mortality did not show this association. Prospective studies are required to establish a causal relationship.

Characterization of the temperature effects on the abundance and richness of the microbiota of Lutzomyia longipalpis, insect vector of Leishmania infantum in America, is an aspect of pivotal importance to understand the interactions between temperature, bacteria, and Leishmania infection. We developed and used a customized device with a temperature gradient (21–34 °C) to assess the temperature preferences of wild females of Lu. longipalpis collected in a rural area (Ricaurte, Cundinamarca, Colombia). Each replicate consisted of 50 females exposed to the gradient for an hour. At the end of the exposure time, insects were collected and separated by the temperature ranges selected varying from 21 °C to 34 °C. They were organized in 17 pools from which total DNA extracts were obtained, and samples were subjected to 16S rRNA amplicon sequencing analyzes. The most abundant phyla across the different temperature ranges were Proteobacteria (17.22–90.73 %), Firmicutes (5.99–77.21 %) and Actinobacteria (1.56–59.85 %). Results also showed an abundance (30 % to 57.36 %) of Pseudomonas (mainly at temperatures of 21–29 °C and 34 °C) that decreased to 6.55 %-13.20 % at temperatures of 31–33 °C, while Bacillus increase its abundance to 67.24 % at 29–33 °C. Serratia also had a greater representation (49.79 %), specifically in sand flies recovered at 25–27 °C. No significant differences were found at α-diversity level when comparing richness using the Shannon-Wiener, Simpson, and Chao1 indices, while β-diversity differences were found using the Bray-Curtis index (F-value of 3.5073, p-value < 0.013, R-squared of 0,4889), especially in the groups of Lu. longipalpis associated at higher temperatures (29–33 °C). It was also possible to detect the presence of endosymbionts such as Spiroplasma and Arsenophonus in the range of 29–33 °C. Rickettsia was only detected in Lu. longipalpis sand flies recovered between 25–27 °C. It was possible to characterize Lu. longipalpis microbiota in response to intraspecific temperature preferences and observe changes in bacterial communities and endosymbionts at different ranges of said environmental variable, which may be important in its vector competence and environmental plasticity to adapt to new climate change scenarios.

5-axis 3D printing presents a promising approach to overcome the limitations of traditional 3-axis methods, particularly in the domain of printed electronics where conformal conductive connections are printed onto the surface of freeform objects. However, this additional freedom comes with a demand for high positioning accuracy, as the rotary movements amplify small axis deviations through the lever effect. This paper presents an approach for an automatically self-calibrating low-cost 5-axis printing system using a built-in 3D touch probe. The calibration data is used to generate a precise kinematic printer model in the Unified Robot Description Format (URDF). Our inverse kinematic solver uses this model in our pathplanning software to generate fully compensated G-code trajectories, maintaining the correct position without needing an expensive high-precision motion system. First results are presented as evaluation which were printed on our low-cost 5-axis system with 3D-printed rotary axes, demonstrating the capability to reliably print circuits on imprecise hardware. The calibration process can be executed quickly and automatically every time the printer is restarted. This approach makes multi-axis 3D printing more accessible and increases potential uses, leading to more precise and cost-effective manufacturing solutions.

Introducción. La ingestión por cáusticos es un problema de salud pública a nivel mundial debido a la alta carga de morbilidad, mortalidad y costos. Por eso, es indispensable tener conocimientos claros sobre la situación en la población adulta, sin extrapolar datos de manejo de población pediátrica. Métodos. Se realizó una revisión crítica de la información disponible con el fin de establecer los datos importantes en el manejo de la esofagitis por cáusticos en población adulta, incluyendo un análisis del tipo de ingesta, volumen, intencionalidad y edad, para ayudar a identificar de manera temprana las complicaciones susceptibles de manejo quirúrgico. Resultados. La endoscopia tiene un rol importante en las primeras 24- 48 horas para establecer la severidad del daño según la clasificación de Zargar, que combinada con la clasificación imagenológica permite alcanzar un mejor pronóstico. No hay un beneficio demostrado con el uso de inhibidores de bombas de protones, mitomicina C, sonda nasogástrica o prótesis esofágica para prevenir las estenosis. Los esteroides tienen beneficio en Zargar ≥ 2B (pero con compromiso de vía aérea) y hay datos prometedores con el uso de sucralfato a altas dosis. En complicaciones derivadas de estenosis se prefiere la dilatación con Savary-Guillard de manera temprana. Luego de 10 años de la ingesta se debe hacer seguimiento endoscópico cada 2 -3 años para tamización de cáncer escamocelular de esófago. Conclusión. La esofagitis por cáusticos es una condición con alta carga de morbilidad, cuyo pronóstico depende de las intervenciones tempranas y un manejo y seguimiento multidisciplinario.

Introducción. Posterior a una esofagectomía parcial o total, el reemplazo del esófago representa un reto para los cirujanos. La selección del sustituto dependerá de diferentes factores, tanto del paciente como del cirujano. Las alternativas disponibles son el estómago, segmentos del colon, el yeyuno supercargado o colgajos libres miocutáneos. Métodos. Se realizó una búsqueda de la literatura en las bases de datos de Medline, Embase y Lilacs, utilizando las palabras claves descritas y aplicando una técnica en bola de nieve, y se seleccionaron los artículos más relevantes. Resultados. El órgano seleccionado debe asegurar una adecuada red vascular, mantener la función deglutoria y tener los menores riesgos posibles. Cada sustituto tiene ventajas particulares, pero todos generan complicaciones a corto y largo plazo. El estómago es el más frecuentemente usado, sin embargo, el reflujo gastroesofágico y la gastroparesia pueden presentarse en un número importante de pacientes. El colon requiere diversos estudios preoperatorios y cada segmento tiene sus características particulares para el ascenso; a largo plazo puede alargarse, tornarse dilatado y tortuoso, afectando la calidad de vida. El yeyuno supercargado permite un adecuado ascenso sin tensión, pero implica una técnica quirúrgica más compleja. Conclusiones. El tubo gástrico es la primera opción, por su menor complejidad técnica y buenos desenlaces. De no estar disponible, se cuenta como alternativas con los diferentes segmentos del colon, el yeyuno supercargado o los colgajos musculocutáneos. Las complicaciones asociadas a estos procedimientos no son despreciables, por lo que se debe tener muy en cuenta la experiencia del grupo quirúrgico.

Abstract New materials and technologies used in construction constantly need improvements, whereby the leveraging of new raw materials for the manufacture of products already in use, such as paving, is required. Thus, this study aimed to determine the mechanical and thermal behavior of pavers containing waste glass and São Tomé stone waste to verify their potential application as cold diffraction. Thereafter, they were comminuted and added to the mixtures for making the pavers having glass waste and São Tomé stone in the range of 0-30% by weight. Mechanical compressive strength and thermal heat absorption tests were performed. Results showed that the replacement of fine aggregates with waste glass and São Tomé stone waste in pavers reached a mechanical resistance of approximately 85% and 73% of that of the reference paver, respectively. The results show that reducing the waste content of pavers can increase the mechanical strength to reach the NBR 9781/87 values. However, pavers with lower mechanical strength can be used in paving pedestrian sidewalks, where the loads are low. Pavers with 30% glass waste achieved a 5.5% reduction in the maximum temperature, which could contribute to the reduction of urban heat islands.

Water hyacinth is classified as a high-risk invasive species but is a source of biomass to obtain bio-oil and biochar by pyrolysis reaction. The Kissinger- Akahira-Sunose model (KAS), Ozawa-Flynn Wall (OFW), and Friedman model, determined the pyrolysis activation energy to be 213.19 kJ mol−1, 222.55 kJ mol−1, and 248.09 kJ mol−1, respectively. Bio-oil was obtained with a 2.2% yield, and a maximum calorific value of 21,641 kJ kg−1. The composition was 44% hydrocarbons, 27% aromatic hydrocarbons, 6% alcohols and phenols, 4% acids, and 19% aldehydes, ketones, ethers, nitriles, and others. A 48.84 wt% biochar was also obtained, gaining energy and active carbon. Bio-oil could be a candidate for the production of refined chemical products.