UAV-Based Smart Educational Mechatronics System Using a MoCap Laboratory and Hardware-in-the-Loop.

Within Industry 4.0, drones appear as intelligent devices that have brought a new range of innovative applications to the industrial sector. The required knowledge and skills to manage and appropriate these technological devices are not being developed in most universities. This paper presents an unmanned aerial vehicle (UAV)-based smart educational mechatronics system that makes use of a motion capture (MoCap) laboratory and hardware-in-the-loop (HIL) to teach UAV knowledge and skills, within the Educational Mechatronics Conceptual Framework (EMCF). The macro-process learning construction of the EMCF includes concrete, graphic, and abstract levels. The system comprises a DJI Phantom 4, a MoCap laboratory giving the drone location, a Simulink drone model, and an embedded system for performing the HIL simulation. The smart educational mechatronics system strengthens the assimilation of the UAV waypoint navigation concept and the capacity for drone flight since it permits the validation of the physical drone model and testing of the trajectory tracking control. Moreover, it opens up a new range of possibilities in terms of knowledge construction through best practices, activities, and tasks, enriching the university courses.

Relación entre el PH salival y la prevalencia de caries dental en escolares de 6 a 12 años de la Institución Educativa San Gabriel, Villa María del Triunfo, 2017 / Relationship between salivary PH and prevalence of dental caries in schoolchildren from 6 to 12 years of age at the San Gabriel Educational Institution, Villa Maria del Triunfo, 2017

Objetivo: Determinar la relación entre el pH salival y la prevalencia de caries dental en escolares de 6 a 12 años de la ciudad de Lima. Metodología: Estudio transversal desarrollado en 129 escolares de la institución educativa San Gabriel, del distrito de Villa María del Triunfo, en 2017. Se obtuvieron las mediciones del pH salival en los pacientes mediante el uso del pH-metro, asistido por tiras de papel y se evaluó la presencia de caries dental mediante el método CPO-D. También se evaluaron las características de sexo y edad de todos los pacientes. La estadística emplea las pruebas de Chi-cuadrado y se trabajó a un nivel de significancia de p < 0,05. Resultados: Se encontró una prevalencia de caries dental del 85,3% en escolares entre los 6 y 12 años. La prevalencia de caries según el género fue del 45,7% en niñas y el 39,5% en varones. No se encontró asociación estadísticamente significativa entre el género y la prevalencia de caries dental (p = 0,935). El 55% del grupo muestral presentó un pH ácido; el 41,1%, un pH neutro, y el 3,9%, un pH alcalino. Se determinó la existencia de una asociación estadísticamente significativa entre pH salival y caries dental (p < 0,001). Conclusiones: Existe una relación directa entre el pH salival y la prevalencia de caries dental. Se calculó que el 95,8% de los pacientes con un pH salival ácido presentaron caries dental. (AU)

Objective: To determine the relationship between the salivary pH and the prevalence of dental caries in school children between the ages of 6 and 12 in the city of Lima. Methods: Transversal study of prevalence carried out on 129 schoolchildren from the "San Gabriel" Educational Institution from the district of Villa Maria del Triunfo, in the year 2017. The salivary pH measurements were obtained using the pH-meter with the respective test-strips, and the presence of caries was evaluated in patients utilizing the CPO-D method. In addition, the sex and age characteristics were evaluated in all the patients. The statistics employed the Chi-squared test and we worked at a level of significance of p < 0.05. Results: The prevalence of dental caries found in schoolchildren between 6 and 12 years old is 85,3%. The prevalence of caries in accordance to gender was 45,7% amongst girls and 39,5% amongst boys. No statistically significant association was found between gender and the prevalence of dental caries (p = 0,935). 55% of the sample group exhibited an acidic pH, while 41,1% had a neutral pH, and 3, 9% an alkaline pH respectively. There is a statistically significant association between the salivary pH and dental caries. (p < 0,001). Conclusions: There's an existing association between salivary pH and the prevalence of dental caries. It was calculated that 95,8% of the patients with an acidic salivary pH presented dental caries. (AU)

Effect heating dwell time has on the retention of heavy metals in the structure of lightweight aggregates manufactured from wastes.

The main objective of this paper was to study how effective thermal treatment is in the retention of different heavy metals (HMs) within the structure of artificial lightweight aggregates (LWAs). These LWAs were manufactured by washing aggregate sludge and sewage sludge. The consequence of increasing the heating dwell time whilst manufacturing these LWAs was also determined. Partitioning of the HMs (Cr, Ni, Cu, Zn, Cd and Pb) was studied by means of the optimized BCR sequential extraction procedure. Then, the leaching ratio (LRx,y) was calculated. Thermal treatment was totally effective for immobilizing most of the elements studied except for a part of the non-residual Zn and Cd fraction which could volatilize, and the fractions of Pb which were water- and acid-soluble, weakly adsorbed, exchangeable, and oxidable. These were more highly concentrated in the LWAs than in the initial waste mixture. The effect of increasing heating dwell time on the retention of heavy metals in the LWAs depended on both the chemical element studied and the heating dwell time. This study is very important since certain rises in the heating dwell time caused a decrease in retention of some specific heavy metals in the LWAs. ABBREVIATIONS: BCR-SEP: optimized BCR sequential extraction procedure; b.d.l: below the detection limit; F1: weakly adsorbed, exchangeable and water- and acid- soluble fraction; F2: reducible fraction; F3: oxidable fraction; F4: residual fraction; HM: heavy metal; ICP-MS: inductively coupled plasma-mass spectroscopy; LOI: loss on ignition; LWA: lightweight aggregate; LWA-5: lightweight aggregate sintered for 5 min; LWA-10: lightweight aggregate sintered for 10 min; LWA-20: lightweight aggregate sintered for 20 min; LWA-30: lightweight aggregate sintered for 30 min; LRx,y: leaching ratio of the element x in the fraction y; n.e: not established; S: compressive strength; SS: sewage sludge; WA24h: water absorption after 24 hours; WAS: washing aggregate sludge; W75S25: mixture of 75% (wt) of the dried washing aggregate sludge and 25% (wt) of the dried sewage sludge; ρb: loose bulk density; ρd: dry particle density; ∑1 + 2 + 3: non-residual fraction; ∑1 + 2 + 3 + 4: total concentration; ∑2 + 3: reducible and oxidable fractions.

[Assessment of right ventricular function using contrast echocardiography in patients with myocardial infarction]. / Valoración de la función ventricular derecha mediante ecocardiografía de contraste en pacientes con infarto agudo de miocardio.

OBJECTIVE: To evaluate right ventricular size, motility, and ejection fraction (RVEF) by contrast echocardiography. METHODS: We studied consecutive patients admitted to the coronary intensive care unit with acute inferior myocardial infarction, without prior infarction and with or without right ventricle involvement, according to accepted electrocardiographic findings. Polygelin, 3.5% solution, was used for contrast echocardiography. The reference standard was equilibrium radionuclide angiography. RESULTS: We studied 44 patients using contrast echocardiography, average patient age 60.8 +/- 10.6 years, 38 men and 6 women. Abnormal right ventricular size (more than 25 mm) yielded a sensitivity of 79%, specificity of 87%, positive and negative predictive values of 92 and 68%, respectively, and a likelihood ratio of 6. Abnormal right ventricular motility had a sensitivity of 70%, specificity of 94%, positive and negative predictive values of 95 and 67%, respectively, and a likelihood ratio of 11.6. Right ventricular ejection fraction < 30% with contrast echocardiography had a sensitivity of 69%, specificity of 97%, positive and negative predictive values of 90 and 88% respectively, and a likelihood ratio of 6.9. CONCLUSION: In patients with acute inferior myocardial infarction, contrast echocardiography with the area-length method is a valid and reproducible technique for evaluating right ventricular ejection fraction, which is easy to perform and can be done at the patient's bedside.

Valoración de la función ventricular derecha mediante ecocardiografía de contraste en pacientes con infarto agudo de miocardio / Assessment of right ventricular function using contrast echocardiography in patients with myocardial infarction

Objetivo. Evaluar el valor diagnóstico del tamaño, la motilidad y la fracción de eyección del ventrículo derecho (FEVD) con ecocardiografía de contraste (EC).Métodos. Incluimos a pacientes consecutivos con el primer acontecimiento de infarto agudo de miocardio inferior con o sin extensión eléctrica al ventrículo derecho. Usamos solución de poligelina al 3,5 por ciento para la EC y se comparó con la angiografía de equilibrio con radionúclidos (AER).Resultados. Estudiamos con EC a 44 pacientes, 38 varones y 6 mujeres, con una edad promedio de 60,8 ñ 10,6 años. Para el tamaño anormal del ventrículo derecho (más de 25 mm) encontramos una sensibilidad del 79 ñ 4 por ciento y especificidad del 87 ñ 3 por ciento, los valores predictivos positivo y negativo fueron del 92 ñ 3 y el 68 ñ 4 por ciento, respectivamente, y el cociente de probabilidad fue de 6. Para la motilidad alterada del ventrículo derecho la sensibilidad fue del 70 ñ 5 por ciento y la especificidad del 94 ñ 2 por ciento, los valores predictivos positivo y negativo fueron del 95 ñ 2 y el 67 ñ 5 por ciento, respectivamente, y el cociente de probabilidad fue de 11,6. Para la fracción de eyección del ventrículo derecho (FEVD) menor del 30 por ciento con EC, la sensibilidad fue del 69 ñ 3 por ciento y la especificidad del 97 ñ 2 por ciento, mientras que los valores predictivos positivo y negativo fueron del 90 ñ 2 y el 88 ñ 4 por ciento, respectivamente, con un cociente de probabilidad de 6,9.Conclusión. En los pacientes con infarto agudo de miocardio inferior la EC con el método de área longitud es una técnica válida y reproducible para evaluar la función ventricular derecha, es simple de realizar, segura y se puede hacer en la cabecera del paciente. (AU)