Abstract In this work, a series of experimental activities that have been generated using Zinc and Zn-Al alloys, as a didactic resource for teaching in the field of Science, Engineering or Materials Technology; of the Manufacturing Processes and Surface Engineering areas. We also propose experiences that can be included in the future, and, finally, we present an analysis of the advantages and limitations of the use of zinc and Zn-Al alloys, which are abundant and underused resources in our countries, as an attractive alternative to improve the results of the teachinglearning process in these subjects. Among the advantages of these resources, it is important to point out that the processing occurs at temperatures much lower than those conventionally used with steels and that there is a range of additional options for teaching different processes.

Resumen En este trabajo se reúnen una serie de actividades experimentales que se han generado, usando al Zinc y a las aleaciones Zn-Al como recurso didáctico para la enseñanza de materias del campo de los Materiales, de la Manufactura y de la Ingeniería de Superficies. Se proponen, asimismo, experiencias que se pueden incluir en el futuro y se presenta un análisis de las ventajas y limitaciones de la utilización didáctica del zinc y las aleaciones Zn-Al, todo esto como una alternativa atractiva para mejorar los resultados del proceso enseñanzaaprendizaje de estas asignaturas. Entre las ventajas de estos recursos conviene señalar que el procesamiento ocurre a temperaturas mucho menores de las convencionalmente empleadas con aceros y que se puede tener una gama de opciones adicionales para la enseñanza de procesos novedosos.

Abstract BACKGROUND: Bipolar enucleation of the prostate can be an effective alternative to the technique of Holmium laser enucleation in patients with large adenomas. OBJECTIVE: To evaluate the efficacy and safety of bipolar enucleation of the prostate for the treatment of obstructive prostatic hyperplasia. MATERIALS AND METHODS: A retrospective, observational, analytic, and descriptive study was conducted on patients indicated for relative and absolute endourologic treatment of prostatic hyperplasia. The preoperative and postoperative (six months) parameters of IPSS, quality of life (QoL), prostate volume, prostate-specific antigen (PSA) levels, pre-micturition and post-micturition bladder volumes, and maximum urinary flow rate (Qmax) were analyzed. Perioperative characteristics: surgery duration, enucleated prostate tissue; enucleated tissue per time unit (g/min), hospital stay, and catheterization duration. The statistical analysis was carried out using the Excel program and the SPSS statistical package. RESULTS: Thirty patients were included in the study. Acute urinary retention was the most common indication for surgery (56%), followed by refractoriness to medical treatment (40%). In means, IPSS was 22.72 ± 7.65, prostate volume 92.97 ± 68.61, prostate-specific antigen 6.4 ± 4.38 ng/mL, surgery duration 113.97 ± 52.1 min, enucleated prostate tissue 65 ± 56.54 g, enucleation/resection efficacy 0.59 ± 0.35 g/min, hospital stay 4.31 days, and postoperative catheterization duration 3.4 days. At month six of follow-up, none of the patients presented with acute urinary retention, mean prostate-specific antigen was 1.61 ± 0.7, and mean IPSS was 4.8 ± 2.1. Only two patients presented with mild stress urinary incontinence. CONCLUSIONS: Bipolar enucleation of the prostate is a safe and effective alternative technique in patients with obstructive prostatic hyperplasia.

Resumen ANTECEDENTES: La enucleación prostática con energía bipolar puede ser una alternativa efectiva a la técnica de enucleación con láser de holmio en pacientes con adenomas de gran tamaño. OBJETIVO: Evaluar la eficacia y seguridad de la enucleación prostática con energía bipolar en pacientes con hiperplasia prostática obstructiva. MATERIALES Y MÉTODOS: Estudio retrospectivo, observacional, analítico y descriptivo, efectuado en pacientes con indicación relativa y absoluta de tratamiento endourológico de hiperplasia prostática. Se analizaron parámetros pre y posoperatorios (seis meses) como: IPSS, calidad de vida (QoL), volumen prostático, concentración de antígeno prostático específico (APE), volumen vesical pre y posmiccional, y flujo urinario máximo (Qmax). Características perioperatorias: tiempo quirúrgico, tejido prostático enucleado, tejido enucleado por unidad de tiempo (g/min), tiempo de hospitalización y de cateterización. Para el análisis estadístico se utilizó el programa Excel y SPSS. RESULTADOS: Se registraron 30 pacientes. La indicación más común de cirugía fue retención aguda de orina (56%) y resistencia al tratamiento farmacológico (40%). La media del IPSS 22.72 ± 7.65 y volumen prostático 92.97 ± 68.61; concentración de antígeno prostático específico 6.4 ± 4.38 ng/mL, tiempo quirúrgico 113.97 ± 52.1 min y tejido prostático enucleado 65 ± 56.5 g. La eficacia de enucleación-resección fue de 0.59 ± 0.35 g/min, tiempo promedio de hospitalización 4.3 días y de cateterización posoperatoria 3.4 días. A seis meses de seguimiento no se reportó retención aguda de orina; la media de antígeno prostático fue 1.6 ± 0.7 e IPSS 4.8 ± 2.1. Solo dos pacientes tuvieron incontinencia urinaria de esfuerzo leve. CONCLUSIÓN: La enucleación prostática con energía bipolar es una técnica alternativa efectiva y segura en pacientes con hiperplasia prostática obstructiva.

An entomological study of triatomine species was carried out to assess their prevalence in 10 localities of the state of Michoacán, Mexico. Entomological indices were calculated to estimate the risk for vector-borne transmission of Trypanosoma cruzi to the human population in this area. Four triatomine species (Triatoma barberi, Triatoma dimidiata, Meccus pallidipennis and Meccus longipennis) were collected from the study area. This is the first report of M. longipennis and T. dimidiata in Michoacán. M. pallidipennis was significantly (p < 0.05) more abundant than any of the other species collected in the study area. Infection indices were greater than 50% for each of the four collected triatomine species. Significantly more triatomines were collected from intradomiciliary areas than from peridomiciliary or sylvatic areas. Infestation, crowding and density indices were low, whereas colonisation indices were high in five localities. The current vectorial conditions in the study area require continuous entomological and serological surveillance to diminish the risk of T. cruzi transmission to human populations.