Universidad La Salle México
  • Mexico City, DF, Mexico
Recent publications
The main objective of this work is supporting the use of sustainable solutions for the management and reuse of agricultural waste from the cereal harvest, such as oats, barley, and triticale, making sheets of artisan paper, innovating the process with the use of different proportions of cellulose obtained from straw residues. The physical and mechanical properties of the obtained sheets showed that basis weight (66-96 g/m 2), thickness (19-300 μm), burst strength (68.9-103.4 kPa), burst index (0.81-1.35 kPam 2 /g) and bulk (2.52-3.12 cm 3 /g), were adequate. Based on what can be observed in the SEM images, it is possible to infer that straw has the function of supporting the sheets using combinations of barley straw and recycled paper. The result of the IR analysis indicated that the sheet with an increase in hydroxyl groups was that obtained with barley straw. Therefore, the treatment was efficient. These results were corroborated by X-ray diffraction analysis, in which the percentage of crystallinity of the barley straw paper was 37.1%. Finally, the results obtained indicated that the crystallinity is better in the sheets containing large amounts of barley straw. The sheet with the highest percentage of crystallinity was that which was made using 100% of barley straw, showing a 37.1 percentage of crystallinity, followed by the sheet made of 100% recycled paper, having a value of 34.4%.
Objetivo: Analizar la asociación de la concentración de con-taminantes atmosféricos y los indicadores epidemiológicos de Covid-19 en la Zona Metropolitana del Valle de México (ZMVM). Material y métodos. Se diseñó un estudio epidemiológico ecológico. Se utilizaron modelos lineales tipo Poisson para variables de conteo y modelos lineales de efectos aleatorios en variables continuas para cuantificar la asociación entre los contaminantes atmosféricos y los indicadores de Covid-19. Los datos obtenidos fueron del 28 de febrero de 2020 al 30 de junio de 2021. La exposición a contaminantes se estratificó por estaciones climáticas. Resultados: Los contaminantes que tuvieron asociación significativa con indicadores de morbilidad y mortalidad fueron CO, NOX, O3 y PM10. En la estación seca fría el CO y el NOX tuvieron efecto sobre los casos diarios confirmados y las defunciones diarias. Las PM10 se asociaron con efecto en los indicadores de casos diarios confirmados, incidencia diaria, porcentaje de hospitalizados y la tasa de letalidad. Conclusiones: Los resultados sugieren una asociación entre el comportamiento epidemiológico de Covid-19 y la exposición a CO, NOX, O3 y PM10, en la que se encontró un mayor efecto en la estación seca-fría en la ZMVM.
In Mexico, indigenous peoples are the most disadvantaged social sectors, which has become more evident during the COVID-19 pandemic. Despite the government efforts to provide medical care, including vaccination, disinformation about the context, the problems, and the indigenous peoples' worldview prevails. In this paper, we present a qualitative analysis of ethnographic and bibliographic information based on fieldwork in 2021, which contrasts with the statistics from State agencies such as the Ministry of Health. We present the problems related to the scarce information and discernment of the indigenous worldview and Modus vivendi, as well as their perspective of the disease. We focus on Chiapas State, in the Mexican southeast, based on the examples of some Chuj, Q'anjob'al, and Tojolab'al communities. We point out proposals to face these changes, including the need to carry out an investigation and activity in situ to counteract the tendency to reinterpret, represent and generalize the indigenous cultural characteristics, which affect the design of health policies.
Temporary antibiotic-loaded cement spacers are widely used for treating chronic periprosthetic hip infections. The aim of this study is to evaluate the short-term tribological performance of ultra-high-molecular-weight polyethylene (UHMWPE) and (60Co) gamma-irradiated cross-linked UHMWPE (XLPE) self-mated systems as frictional pairs for temporary total hip spacers. A three-axial hip joint simulator, FIME II, was used to test the UHMWPE and XLPE self-mated systems under variable load profiles. A fetal bovine serum solution was used as a lubricant. After simulation tests, wear measurements of damaged coupled surfaces were made with a coordinate measuring machine. Finally, surfaces were characterized with scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and nanoindentation tests. The mass loss test results for UHMWPE were 11.91 ± 3.43 mg for the cups and 4.57 ± 0.92 mg for the heads. Whereas, the results for XLPE showed a significant reduction, with mean mass loss values of 6.59 ± 0.14 mg for the cups and 2.82 ± 0.59 mg for the heads, suggesting the viability of the self-mated XLPE contact pair for a temporary total hip spacer.
Background: Laparoscopic surgery is a surgical procedure by which access to the abdomino-pelvic cavity is obtained through small incisions. The incidence of bowel injury is estimated at 0.5% and of injury to major blood vessels (iliac, aorta, cava) at the time of access at 1%. Theoretical benets of optical trocar access include immediate and/or early recognition of injury, as well as failed entry, on the assumption that the layers of the abdominal wall are observed with the optical trocar until access has been achieved. To determine whether the optical trocar is a saferObjective: laparoscopic access method compared to the other techniques with direct trocar, Veress needle and Hasson open technique. Material and Methods: Observational, analytical, prospective cohort study with four arms. The study included women over 18 years of age who attended the gynaecology and laparoscopic surgery department of the Hospital Ángeles del Pedregal. The number of attempts and access time, as well as the presence of complications were quantied. Results and Conclusions: Trocar access had an advantage over the other techniques, both in access time and lower incidence of complications. The number of attempts to enter the cavity was similar to the open technique. We can conclude that the optical trocar technique is safer than the other techniques even over the open technique (Hasson).
Preeclampsia is characterized by arterial hypertension in the pregnant patient that can condition the affection to a target organ. It is considered one of the main causes of morbi maternal-fetal mortality, affecting approximately between 3 to 8% of pregnancies at the world. Due to its relevance, there are currently screening and risk assessment methods to know if a patient can present this pathology. (1) Currently aspirin is a drug used worldwide for its anti-inammatory and antiaggregant activity platelet, so since the 70's its consumption was proposed as a method of prevention for preeclampsia. (2).
Background: Postgraduate training in plastic surgery is heterogeneous between countries, with exposure to aesthetic surgery being a reflection of this. Fellowships in Mexico have usually consisted of tutorial teaching, providing graduates with experience but a lack of formal structure. The aim of his work is to present a University-backed program focused on aesthetic surgery and propose the expansion of this kind of program. Methods: A retrospective cross-sectional review of surgical cases was performed over a five-year period from 2015 to 2019. Data were obtained from the senior surgeon's practice charts. Information was recorded using a data sheet including patients' demographic characteristics, procedures performed and type of anesthesia applied. Descriptive analyses of patient demographic and clinical characteristics were performed. Continuous variables are expressed in central tendency measures, and categorical values are presented as percentages. Results: 1282 procedures were performed on 885 patients, 797 females (90%) and 88 males (10%). Mean age was 44.6 ± 13.8 years. Case load consisted in 545 breast procedures (42.5%), 372 body contour surgeries (29.0%), 305 facial aesthetic procedures (23.8%) and 60 miscellaneous procedures (4%). The most common surgeries were breast augmentation (249, 19.4%), alloplastic breast reconstruction (165, 12.8%), blepharoplasty (163, 12.7%), liposuction (151, 11.7%), and abdominoplasty (107, 8.3%). Conclusions: A University backed program focused on aesthetic surgery is feasible and desirable in multiple national and international institutions.
Introducción: El Apgar quirúrgico (AQ) es un sistema de 10 puntos que valora tres variables intraoperatorias: frecuencia cardíaca más baja, presión arterial media más baja y sangrado. El AQ es un indicador de la mortalidad y morbilidad en el postoperatorio inmediato. Objetivo: Describir la incidencia del puntaje AQ en pacientes postoperados y con activación del código 77 en el Hospital Ángeles Pedregal. Material y métodos: Estudio observacional, descriptivo, retrospectivo, de corte transversal que incluyó pacientes con indicación de activación del código 77 en su postoperatorio inmediato y traslado a Unidad de Cuidados Intensivos, durante el período de enero a diciembre de 2015 en el Hospital Ángeles Pedregal. Resultados: Se contó con 58 pacientes de los cuales 68% obtuvieron un Apgar quirúrgico ≥ 7 puntos (estables) y 32% un Apgar quirúrgico 6 (inestables). La incidencia del Apgar quirúrgico 6 para el período de estudio fue de 12 casos por cada 100 personas intervenidas con una sensibilidad del 68%. Conclusiones: El AQ puede considerarse un criterio confiable para la activación del código 77 en aquellos pacientes con puntaje AQ ≤ 6 durante el postoperatorio inmediato, permitiendo un manejo oportuno de las complicaciones postquirúrgicas y la disminución de riesgo de morbimortalidad.
We introduce the concept of codeterminantal graphs, which generalize the concepts of cospectral and coinvariant graphs. To do this, we investigate the relationship of the spectrum and the Smith normal form (SNF) with the determinantal ideals. We establish a necessary and sufficient condition for graphs to be codeterminantal on R[x], and we present some computational results on codeterminantal graphs up to 9 vertices. Finally, we show that complete graphs and star graphs are determined by the SNF of its distance Laplacian matrix.
Decision making in wages is generally a hard task. The aim of this work is to identify government conditions, personal conditions of the businessperson, and organizational circumstances that affect wage levels in the automotive industry in Mexico City using a linguistic fuzzy-set approach. We conducted a questionnaire, consisting of 23 observation variables with a five-point Likert scale. Independent variables were measured from 1 (“not important”) to 5 (“very important”). Based on the literature review and results of interviews, a total of 169 questionnaires were sent to participants using Google Forms. The results of the linguistic fuzzy-set approach identify three main conditions influencing the salary levels in the automotive industry in Mexico City, including unskilledmanpower, the neoliberal economic model, and political and trade reforms. On the other hand, organizational conditions are not considered relevant in determining wage levels. Based on the findings, some recommendations have been proposed to help government, firm leaders, and businesspeople design appropriate personnel policies to achieve better salary satisfaction for employees in the future. This work shows a model based on the fuzzy-set approach that is a potential tool to overcome the difficulties posed by a complex environment.
The development of high-precision tasks, such as machining, needs a positioning device for the cutting tool with the smallest possible error. Multiple design factors need to be considered to ensure a mechatronic device successfully performs such tasks. One of these factors may be attributed to the control scheme, which is responsible for controlling the position of the machine. In view of the importance of designing a good control scheme for a robotic system, in this paper, we propose a new extension of the robust integral sign of the error (RISE) for the positioning device a parallel kinematic machine (PKM). This extension consists in including a nominal feedforward term based on the inverse dynamic model of the robot and replacing the RISE fixed feedback gains with adaptive ones. The RISE part of the proposed controller ensures semi-global asymptotic stability. Moreover, it can accommodate sufficiently smooth bounded disturbances. The feedforward part cancels the nonlinearities of the system, improving the tracking performance of the controller. The adaptive feedback gains produce corrective actions when an increase in the tracking errors is due to the contact forces that occur during the machining process. A Lyapunov-based stability analysis is conducted to prove the semi-global asymptotic stability of the proposed control solution. To show its effectiveness realtime experiments are performed for two case studies; the first one is on a free motion trajectory, and the second on milling experiments under three different forward speeds on SPIDER4, a redundantly actuated PKM.
Antecedentes: La menopausia se relaciona con cambios en la composición corporal que el uso de terapia hormonal (TH) puede revertir. Objetivo: Determinar el efecto de la TH parenteral y oral sobre la composición corporal en la menopausia. Material y métodos: Se realizó un estudio retrolectivo que incluyó a 86 mujeres de 45 a 55 años, con FSH > 20 Ul/ml, antecedente de histerectomía y sintomatología vasomotora, a las cuales se les administró TH por vía oral (44 pacientes) o parenteral (42 pacientes) durante seis meses. Se les realizó impedancia bioeléctrica antes y después del tratamiento. Resultados: La TH por vía oral se asoció con una disminución de diferentes parámetros de la composición corporal entre los que destaca la disminución de la grasa visceral (p < 0.05). La TH parenteral no mostró modificación en la composición corporal. Conclusión: La TH por vía oral modifica de manera positiva la composición corporal, lo cual puede contribuir a regular el estado metabólico.
Metabolic syndrome (MS) is a cluster of metabolic signs that increases the risk of developing type 2 two diabetes mellitus and cardiovascular diseases. MS leads to pancreatic beta cell exhaustion and decreased insulin secretion through unknown mechanisms in a time-dependent manner. ATP-sensitive potassium channels (KATP channels), common targets of anti-diabetic drugs, participate in the glucose-stimulated insulin secretion, coupling the metabolic status and electrical activity of pancreatic beta cells. We investigated the early effects of MS on the conductance, ATP and glybenclamide sensitivity of the KATP channels. We used Wistar rats fed with a high-sucrose diet (HSD) for 8 weeks as a MS model. In excised membrane patches, control and HSD channels showed similar unitary conductance and ATP sensitivity pancreatic beta cells in their KATP channels. In contrast, MS produced variability in the sensitivity to glybenclamide of KATP channels. We observed two subpopulations of pancreatic beta cells, one with similar (Gly1) and one with increased (Gly2) glybenclamide sensitivity compared to the control group. This study shows that the early effects of MS produced by consuming high-sugar beverages can affect the pharmacological properties of KATP channels to one of the drugs used for diabetes treatment.
Más de un año después del primer confinamiento por la pandemia del COVID-19, el resurgimiento de los contagios no augura un pronto regreso a la normalidad. Las implicaciones son diversas, por ello el objetivo de este documento fue mostrar el impacto económico de los rebrotes, y sus implicaciones y perspectivas para la economía mexicana. Para el análisis de los datos se realizó un pronóstico basado en series de tiempo. Para finales de 2022, el PIB no presentará cambios drásticos. Se espera que las remesas disminuyan en los próximos meses, pero que después retomen su tendencia al alza. Para el índice de desempleo, se espera que disminuya en los próximos meses, para retomar el mismo nivel después y que disminuya nuevamente a finales del año 2022. Para el índice nacional de precios y cotizaciones, se espera que tenga un aumento para diciembre de 2022. También el Índice de Consumo Mensual seguirá creciendo. Finalmente, el índice de precios y cotizaciones muestra tendencia a mantenerse estable durante los próximos meses y para la serie del tipo de cambio, se espera que siga creciendo paulatinamente durante los próximos meses. Este panorama evidencia la importancia de los modelos matemáticos para comprender el panorama económico y son herramientas necesarias para la toma de decisiones.
Metabolic syndrome (MetS) contributes to the spread of cardiovascular diseases, diabetes mellitus type 2, and neurodegenerative diseases. Evaluation of sex- and hormone-dependent changes in body weight, blood pressure, blood lipids, oxidative stress markers, and alterations in different types of memory in Sprague–Dawley rats fed with a high fat and high fructose (HFHF) diet were evaluated. After 12 weeks of feeding the male and female rats with HFHF, body weight gain, increase in blood pressure, and generation of dyslipidemia compared to the animals fed with chow diet were observed. Regarding memory, it was noted that gonadectomy reverted the effects of HFHF in the 24 h novel object recognition task and in spatial learning/memory analyzed through Morris water maze, males being more affected than females. Nevertheless, gonadectomy did not revert long-term memory impairment in the passive avoidance task induced by HFHF nor in male or female rats. On the other hand, sex-hormone–diet interaction was observed in the plasma concentration of malondialdehyde and nitric oxide. These results suggest that the changes observed in the memory and learning of MetS animals are sex- and hormone-dependent and correlate to an increase in oxidative stress.
Las plantas medicinales son de interés farmacéutico, debido a que tienen diferentes propiedades biológicas, entre las que se destaca, la actividad antioxidante y, de la cual, se conoce que existe una relación con la concentración de los compuestos fenólicos, por su capacidad de reducir los radicales libres. Es así, que se propuso evaluar la actividad antioxidante y la cuantificación de fenoles y flavonoides totales, de 11 extractos etanólicos de plantas, empleadas en la medicina tradicional, para el tratamiento de infecciones urinarias (IU). Se evaluó la actividad antioxidante, por los métodos de DPPH y FRAP y se cuantificó el contenido fenólico y de flavonoides, por el método Folin-Ciocalteu y tricloruro de aluminio, respectivamente. Se encontró que, de los 11 extractos evaluados, los que presentaron el mayor contenido de estos metabolitos y de potencial antioxidante fueron: Uncaria tomentosa, Sedum praealtum y Kohleria hirsuta. Este trabajo permitió contribuir al conocimiento fitoquímico y antioxidante de plantas, usadas para tratar IU y se sugiere que U. tomentosa, S. praealtum y K. hirsuta sean objeto de futuros estudios biodirigidos, así como la evaluación de otras actividades biológicas.
Introducción: En diciembre 2019 se reportó el primer caso de neumonía atípica en China, causado por SARS-CoV-2, la cual afecta principalmente el tracto respiratorio. Nuevos estudios han reportado síntomas gastrointestinales como manifestación primaria del COVID-19, pero existen pocos reportes que hayan relacionado al SARS-CoV-2 con pancreatitis aguda. Objetivo: Describir la aparición de pancreatitis y su correlación con el resto de las manifestaciones clínicas, así como considerar al páncreas como órgano blanco del virus, que pudiera empeorar el pronóstico de estos pacientes. Material y métodos: Se trata de un estudio descriptivo, trasversal, retrospectivo, no experimental de tipo serie de casos, realizado del 15 de marzo al 25 de mayo del 2020. El área de estudio corresponde a todos los pacientes que ingresaron a terapia intensiva con diagnóstico por PCR de COVID-19. Las variables estudiadas se recopilaron del expediente clínico. Resultados: Se estudiaron 30 pacientes de terapia intensiva, de los cuales ocho presentaron datos bioquímicos y tomográficos compatibles con pancreatitis aguda, todos presentaron linfopenia, elevación de amilasa y lipasa, hiperbilirrubinemia a expensas de directa; sólo un caso demostró litiasis vesicular sin ser la causa de pancreatitis, se utilizaron SOFA y APACHE para estadificar la gravedad, fallecieron todos con un promedio de 9.8 días en terapia intensiva.
During pregnancy, there is a state of immune tolerance that predisposes them to viral infection, causing maternal-fetal vulnerability to the adverse effects of COVID-19. Bacterial coinfections significantly increase the mortality rate for COVID-19. However, it is known that all drugs, including antibiotics, will enter the fetal circulation in a variable degree despite the role of the placenta as a protective barrier and can cause teratogenesis or other malformations depending on the timing of exposure to the drug. Also, it is important to consider the impact of the indiscriminate use of antibiotics during pregnancy can alter both the maternal and fetal-neonatal microbiota, generating future repercussions in both. In the present study, the literature for treating bacterial coinfections in pregnant women with COVID-19 is reviewed. In turn, we present the findings in 50 pregnant women hospitalized diagnosed with SARS-CoV-2 without previous treatment with antibiotics; moreover, a bacteriological culture of sample types was performed. Seven pregnant women had coinfection with Staphylococcus haemolyticus, Staphylococcus epidermidis, Streptococcus agalactiae, Escherichia coli ESBL +, biotype 1 and 2, Acinetobacter jahnsonii, Enterococcus faecium, and Clostridium difficile. When performing the antibiogram, resistance to multiple drugs was found, such as macrolides, aminoglycosides, sulfa, dihydrofolate reductase inhibitors, beta-lactams, etc. The purpose of this study was to generate more scientific evidence on the better use of antibiotics in these patients. Because of this, it is important to perform an antibiogram to prevent abuse of empirical antibiotic treatment with antibiotics in pregnant women diagnosed with SARS-CoV-2.
Introduction The COVID-19 pandemic has been particularly difficult for populations at risk for mental health problems, such as healthcare professionals and medical students. In the present study, we evaluated the effect of the pandemic on mental health in a sample of Mexican medical students with and without a mental health diagnosis. Method Longitudinal and descriptive study based on scales of suicidal ideation, depressive symptoms and risk of alcohol consumption, conducted in April and December 2020. Results Sample includes 247 medical students, 64.4% are women. Prevalence of depression increased between April and December from 19.84% to 40.08%. In the case of women from 23.67% to 42.60% (χ2 = 0.000) and in men from 11.54% to 34.62% (χ2 = 0.001). In April 16.92% of healthy students presented some sign of depression and in December the percentage increased to 40.80% (χ2 = 0.000). Regarding medicated students, the prevalence in April was 32.61% and in December it was 36.96% (χ2 = 0.662). In April, the medicated students with risk of suicidal ideation were 17 out of 46 (36.96%), compared to the students without a diagnosis of psychiatric illness were 29 out of 201 (13.43%) (χ2 = 0.000). For December, the non-medicated students at risk of suicidal ideation were 34 out of 201 (16.91%), and the medicated students were 12 out of 46 (26.09%) (χ2 = 0.149). Conclusions The pandemic has increase the rate of depression in medical students, being more severe in women. Students under psychiatric treatment showed a higher prevalence of depression; however, the fact of being under treatment resulted in a protective factor for the increase in the prevalence of depression. It is important to deepen the understanding of the causes of depression and to disseminate among the university community the benefits of early detection and treatment of people with socio-emotional disorders.
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1,296 members
Roberto Antonio Vázquez
  • Faculty of Engineering
Juan Rodrigo Salazar
  • Facultad de Ciencias Químicas
Arely Vergara
  • Vicerrectoría de Investigación. Facultad de Ciencias Químicas
Bertha Fortoul
  • Facultad de Humanidades y Ciencias Sociales
Benjamin Franklin 47 Col. Condesa, 06140, Mexico City, DF, Mexico