A Review of EPDM (Ethylene Propylene Diene Monomer) Rubber-Based Nanocomposites: Properties and Progress.

Ethylene propylene diene monomer (EPDM) is a synthetic rubber widely used in industry and commerce due to its high thermal and chemical resistance. Nanotechnology has enabled the incorporation of nanomaterials into polymeric matrixes that maintain their flexibility and conformation, allowing them to achieve properties previously unattainable, such as improved tensile and chemical resistance. In this work, we summarize the influence of different nanostructures on the mechanical, thermal, and electrical properties of EPDM-based materials to keep up with current research and support future research into synthetic rubber nanocomposites.

Trabajo Emocional en grupos ocupacionales de Latinoamérica: Una revisión de alcance / Emotional work in occupational groups of Latin America: A scoping review

Introducción: El Trabajo Emocional deteriora la salud mental de los colaboradores, quienes, en interacción con usuarios, regulan sus emociones para expresar las prescritas en la organización. Objetivo: Mapear sistemáticamente los hallazgos principales sobre el Trabajo Emocional en grupos ocupacionales de Latinoamérica a partir de la revisión de artículos científicos publicados entre 2009 y 2020, mediante una revisión de alcance. Materiales y métodos: A partir de la metodología PRISMA-ScR, se realizó la búsqueda en las bases de datos LILACS, Redalyc, Dialnet, DOAJ, BVS, Gale One File: Psychology y EBSCOhost; con las palabras clave "trabajo emocional" (español), "emotional labor"/"emotional work" (inglés) y "trabalho emocional" (portugués); y una matriz de registro documental como formulario de gráfico de datos. Resultados: De 186 artículos, se seleccionó 17, con las siguientes características: la mayoría fueron de Brasil; grupos de trabajadores en salud y docentes; con definición de trabajo emocional en 6 categorías; y se utilizaron 11 instrumentos de medición. Conclusiones: Existe amplia concepción sobre el trabajo emocional, sin embargo, la evidencia en Latinoamérica aún es limitada, por ello es necesario continuar investigación de su incidencia en diferentes escenarios laborales, para obtener una comprensión global del constructo.

Introduction: Emotional work deteriorates the mental health of employees who interact with the public and therefore must regulate their emotions in order to express those established by the organization. Objective: To systematically map the main findings of Emotional Work in occupational groups of Latin America based on the revision of scientific articles published between 2009 and 2020 through a scoping review. Materials and methods: A PRISMA-ScR methodology with the keywords "trabajo emocional" (Spanish), "emotional labor"/"emotional work" (English) and "trabalho emocional" (Portuguese) was used to search the following databases: LILACS, Redalyc, Dialnet, DOAJ, BVS, Gale One File: Psychology and EBSCOhost. A document record matrix was used as format for data graphic. Results: From 186 articles, 17 were selected with the following characteristics: majority were from Brazil; included health employees and professors; defined emotional work using 6 categories; used 11 measurement instruments. Conclusions: There is a wide understanding of the topic of emotional work, however the evidence in Latin America is limited, which is why it is necessary to continue investigating its incidence in different work environments in order to obtain a global understanding of the construct.

Pleural involvement in differentiated thyroid cancer / Compromiso pleural en cáncer diferenciado de tiroides

Abstract Thyroid cancer is the most common endocrine cancer. It generally has a good prognosis, with a 10-year survival rate of over 90%. Pleural metastasis is uncommon. We present two cases of papillary thyroid cancer with pleural metastases. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2216).

Resumen El cáncer de tiroides es la neoplasia endocrinológica más común. Suele presentar un buen pro nóstico con una sobrevida a 10 años mayor al 90%. El compromiso metastásico pleural es poco frecuente. Presentamos dos casos de cáncer papilar de tiroides con compromiso pleural metastásico. (Acta Med Colomb 2022; 47. DOI:https://doi.org/10.36104/amc.2022.2216).

Managing colombian farmers price risk exposure with electrical derivatives market.

Food security is among the most pressing global concerns. It is principally threatened by the combination of rural migration and the pressure of climate change. In order to mitigate these effects, the need to promote stable conditions for small producers -who generate 80% of the world's food- has arose. In search to improve market conditions, this study aims to evaluate the feasibility of cross-hedging between electrical derivatives market and spot agricultural products in Colombia. This hypothesis is proposed, as Colombia depends upon hydro-electricity, an electricity source which is heavily influenced by climatic conditions, particularly the "El Niño" southern oscillation (ENSO). The prices of agricultural products are thus volatile, and subject to this phenomenon. ENSO is presumed to be an important link between these two markets. To contrast the hypothesis, the most commonly- methods in cross-hedging literature were employed to estimate hedge ratios: OLS, Error Correction Models, and GARCH estimations. This last estimation was found to be the one with the best performance for hedge ratio estimation. Despite this, of 93 products analyzed, statistically significant relationships were found for only nine. Besides, it was found that cross-hedging contributes to a risk reduction of not more than 32%.

Effect of inoculum on the anaerobic digestion of food waste accounting for the concentration of trace elements.

The production of renewable energy in the form of methane from the anaerobic digestion (AD) of food waste (FW) varies depending on factors such as the quantity and quality of the inoculum. This research evaluated the influence of trace elements (Ca, K, Fe, Zn, Al, Mg, Co, Ni, and Mo) present in inoculum from different sources (wastewater treatment plants (WWTPs): 2 agro-industrial WWTPs and 1 municipal WWTP) on the AD of FW. This study found that the source of the inoculum determines the content of macronutrients and trace elements, which can alter the requirements of the AD process and therefore affect methane production. The inoculum obtained from municipal WWTPs contain potentially inhibitory concentrations of Zn and Al that negatively affect methane production (<70 mL CH4·gVS-1), the hydrolysis constant (<0.19 d-1), and the lag-phase (>7 days). It was also found that high concentrations of trace elements such as Ni (35.2 mg kg-1) and Mo (15.4 mg kg-1) in the inoculum increase methane production (140.7 mL CH4·gVS-1) and hydrolysis constant (>0.18d-1) in addition to presenting short lag-phase (<1 day) in the AD of food waste.