Simulation of Bullet Fragmentation and Penetration in Granular Media.

The aim of this work is to simulate the fragmentation of bullets impacted through granular media, in this case, sand. In order to validate the simulation, a group of experiments were conducted with the sand contained in two different box prototypes. The walls of the first box were constructed with fiberglass and the second with plywood. The prototypes were subjected to the impact force of bullets fired 15 m away from the box. After the shots, X-ray photographs were taken to observe the penetration depth. Transient numerical analyses were conducted to simulate these physical phenomena by using the smooth particle hydrodynamics (SPH) module of ANSYS® 2019 AUTODYN software. Advantageously, this module considers the granular media as a group of uniform particles capable of transferring kinetic energy during the elastic collision component of an impact. The experimental results demonstrated a reduction in the maximum bullet kinetic energy of 2750 J to 100 J in 0.8 ms. The numerical results compared with the X-ray photographs showed similar results demonstrating the capability of sand to dissipate kinetic energy and the fragmentation of the bullet caused at the moment of impact.

Extubaciones no programadas en pacientes sometidos a fase de destete en cuidados intensivos: incidencia y factores de riesgo / Unplanned extubations in patients in the ventilator weaning phase in the intensive care unit: Incidence and risk factors

Objetivos. Cuantificar la incidencia de extubaciones no programadas (ENP) en una unidad de cuidados intensivos (UCI) polivalente y determinar los factores de riesgo. Método. Estudio observacional, prospectivo y analítico realizado en una UCI polivalente de 8 camas durante un período de 6 meses. Los 79 participantes se eligieron por orden consecutivo de ingreso. Los criterios de inclusión fueron que estuviesen sometidos a ventilación mecánica (VM) durante al menos durante 12h y que pasaran por la fase de destete de VM. Se valoró edad, días con tubo endotraqueal (TET), días de estancia en la UCI, fase de destete de VM y nivel de sedación y/o agitación mediante la escala sedación agitación de Riker y el índice pronóstico APACHE II. Se calculó la densidad de incidencia para ENP y se compararon las variables medidas en el grupo de pacientes extubados y no extubados mediante el test de comparación de la U de Mann-Whitney. Resultados. De los 79 casos que constituyeron la muestra, se constataron 15 casos (18,9%) de ENP, de los que el 76,9% ocurrió durante la fase de destete. Un 73,3% (11 casos) se debió a autoextubación, un 20% (3 casos) por causa accidental y un 6,6% (un caso) por obstrucción del TET. La edad menor o igual a 60 años fue un factor de riesgo, no objetivándose relación con otros factores a estudio: días de estancia, días con TET y APACHE. Conclusiones. Los pacientes en riesgo de ENP se caracterizan por una edad más joven y un estado de agitación según la escala Riker. Las ENP ocurren, generalmente, cuando el paciente se encuentra durante la fase de destete del ventilador(AU)

Objectives. To identify the incidence of unplanned extubations (UE) in a general intensive care unit (ICU) and associated risk factors. Methods. An analytical, observational and prospective study was performed in an eight-bed general ICU over a 6-month period. The participants consisted of 79 consecutive patients who underwent mechanical ventilation for 12h or more and who were under the ventilator weaning phase. The variables studied were age, days of endotracheal intubation, length of stay in the ICU, weaning phase and the APACHE II prognostic score; the degree of sedation and/or agitation was evaluated using Riker's Sedation-Agitation Scale. The incidence density of UEs was calculated and the variables measured in the extubated and non-extubated groups were compared using the Mann Whitney U-test. Results. Among the 79 patients studied, UE occurred in 15 (18.9%). Of these events, 76.9% occurred during the ventilator weaning phase. There were 11 cases (73.3%) of self-extubations, three cases (20%) of accidental removal and one case (6.6%) of endotracheal tube obstruction. Age equal to or less than 60 years was a risk factor. No relationship was found with the remaining factors studied: days of hospital stay, days of endotracheal intubation or APACHE score. Conclusions. Patients at risk for UE were younger and showed agitation on the Riker scale. UEs usually occurred during the ventilator weaning phase(AU)

[Unplanned extubations in patients in the ventilator weaning phase in the intensive care unit: Incidence and risk factors]. / Extubaciones no programadas en pacientes sometidos a fase de destete en cuidados intensivos: incidencia y factores de riesgo.

OBJECTIVES: To identify the incidence of unplanned extubations (UE) in a general intensive care unit (ICU) and associated risk factors. METHODS: An analytical, observational and prospective study was performed in an eight-bed general ICU over a 6-month period. The participants consisted of 79 consecutive patients who underwent mechanical ventilation for 12 h or more and who were under the ventilator weaning phase. The variables studied were age, days of endotracheal intubation, length of stay in the ICU, weaning phase and the APACHE II prognostic score; the degree of sedation and/or agitation was evaluated using Riker's Sedation-Agitation Scale. The incidence density of UEs was calculated and the variables measured in the extubated and non-extubated groups were compared using the Mann Whitney U-test. RESULTS: Among the 79 patients studied, UE occurred in 15 (18.9%). Of these events, 76.9% occurred during the ventilator weaning phase. There were 11 cases (73.3%) of self-extubations, three cases (20%) of accidental removal and one case (6.6%) of endotracheal tube obstruction. Age equal to or less than 60 years was a risk factor. No relationship was found with the remaining factors studied: days of hospital stay, days of endotracheal intubation or APACHE score. CONCLUSIONS: Patients at risk for UE were younger and showed agitation on the Riker scale. UEs usually occurred during the ventilator weaning phase.

Factores de riesgo cardiovascular en una muestra de mu- jeres jóvenes mexicanas / Cardiovascular risk factors in a sample of young Mexican women

The present work describes the prevalence of cardiovascular risk factors in young mexican women. 96 women from 18 to 40 years of age were included. All of them were measured (height, waist and hip) and weighed, blood pressure was registered, laboratory exams were taken and a questionnaire was answered. Cardiovascular risk factors prevalence was estimated and the average concentrations of lipids and glucose and systolic and diastolic blood pressure were compared by age, BMI and WHI group. Of the studied women, 51% were overweight or obese and 51% had visceral obesity with a high prevalence of lipids abnormalities (hypoalpha-lipoproteinemia and hypertrigliceridemia), which increases progressively with age. Only 5% and 4% had normal to high systolic and dyastolic blood pressures and 7% had blood glucose > 110 mg/dL. In this sample of women with similar social, demographic, economic, and cultural characteristics, a high proportion was identified with body weight problems and lipids abnormalities, a frequent finding in Latin populations with multiple etiologies and associated with different cardiovascular risk factors.

[Cardiovascular risk factors in a sample of young Mexican women]. / Factores de riesgo cardiovascular en una muestra de mu- jeres jóvenes mexicanas.

The present work describes the prevalence of cardiovascular risk factors in young mexican women. 96 women from 18 to 40 years of age were included. All of them were measured (height, waist and hip) and weighed, blood pressure was registered, laboratory exams were taken and a questionnaire was answered. Cardiovascular risk factors prevalence was estimated and the average concentrations of lipids and glucose and systolic and diastolic blood pressure were compared by age, BMI and WHI group. Of the studied women, 51% were overweight or obese and 51% had visceral obesity with a high prevalence of lipids abnormalities (hypoalpha-lipoproteinemia and hypertrigliceridemia), which increases progressively with age. Only 5% and 4% had normal to high systolic and dyastolic blood pressures and 7% had blood glucose > 110 mg/dL. In this sample of women with similar social, demographic, economic, and cultural characteristics, a high proportion was identified with body weight problems and lipids abnormalities, a frequent finding in Latin populations with multiple etiologies and associated with different cardiovascular risk factors.