Tenacidad a la fractura de compuestos cermets 3Al2O3*2SiO2/Ag manufacturados por molienda de alta energía

La fabricación de materiales compuestos de matriz cerámica reforzados con partículas metálicas han propiciado la formación de nuevos materiales conocidos como compuestos CERMETS, materiales que debido a sus elementos precursores poseen propiedades distintas a las de los materiales convencionales. En este trabajo se establece la ruta de fabricación de materiales compuestos cermets base 3Al2O3*2SiO2 reforzados con partículas metálicas de Ag a partir de la formación de la composición química en peso de polvos de 3Al2O3*2SiO2 / 1% Ag en busca de un aumento en la tenacidad a la fractura con respecto al cerámico base. La composición química de polvos es sometida a un proceso de mezcla molienda de alta energía en seco en un molino tipo planetario por 2 horas a 200 rpm. Los polvos posteriormente son conformados en muestras cilíndricas de 20 mm de diámetro y 3 mm de espesor mediante la aplicación de carga uniaxial en frío de 200 MPa. Las muestras son sinterizadas a 1500°C y 1600°C por una y dos horas en un horno de resistencia eléctrica en atmósfera controlada de gas nitrógeno. Los compuestos fabricados son analizados microestructuralmente por microscopia óptica y electrónica de barrido. Se determina la densidad y las propiedades mecánicas de dureza y tenacidad a la fractura, las dos últimas por el método de indentación. Los resultados muestran la viabilidad de fabricación de materiales compuestos cermets así como los cambios en la densidad, la dureza y la tenacidad a la fractura, con respecto al cerámico 3Al2O3*2SiO2 sin refuerzo metálico

Evidence of spatial clustering of childhood acute lymphoblastic leukemia cases in Greater Mexico City: report from the Mexican Inter-Institutional Group for the identification of the causes of childhood leukemia

BackgroundA heterogeneous geographic distribution of childhood acute lymphoblastic leukemia (ALL) cases has been described, possibly, related to the presence of different environmental factors. The aim of the present study was to explore the geographical distribution of childhood ALL cases in Greater Mexico City (GMC).MethodsA population-based case-control study was conducted. Children <18 years old, newly diagnosed with ALL and residents of GMC were included. Controls were patients without leukemia recruited from second-level public hospitals, frequency-matched by sex, age, and health institution with the cases. The residence address where the patients lived during the last year before diagnosis (cases) or the interview (controls) was used for geolocation. Kulldorff’s spatial scan statistic was used to detect spatial clusters (SCs). Relative risks (RR), associated p-value and number of cases included for each cluster were obtained.ResultsA total of 1054 cases with ALL were analyzed. Of these, 408 (38.7%) were distributed across eight SCs detected. A relative risk of 1.61 (p<0.0001) was observed for the main cluster. Similar results were noted for the remaining seven ones. Additionally, a proximity between SCs, electrical installations and petrochemical facilities was observed.ConclusionsThe identification of SCs in certain regions of GMC suggest the possible role of environmental factors in the etiology of childhood ALL

Electrónica y Telecomunicaciones

Desde hace algún tiempo, se vienen registrando en el mundo cambios tecnológicos importantes que repercuten en el aumento de la capacidad para manejar información fiable de manera segura, se desarrollan cada día dispositivos electrónicos nuevos que vienen a mejorar los sistemas ya existentes y se diseñan nuevas formas para utilizarlos

Caracterización y modelado de sensores y transductores electrónicos: teoría y experimentos

Desde hace algún tiempo, se vienen registrando en el mundo cambios tecnológicos importantes que repercuten en el aumento de la capacidad para manejar información fiable de manera segura, se desarrollan cada día dispositivos electrónicos nuevos que vienen a mejorar los sistemas ya existentes y se diseñan nuevas formas para utilizarlos

Congreso Internacional de Bioeconomía Circular - Fase III 1/3

Ponentes: Diana Arrioja, CANACINTRA Diego Montenegro Ernst, Representante del IICA México Luis Ángel Rodríguez del Bosque, Director General del INIFAP Martha Escalante Escoffíe, Secretaria Ejecutiva Salvador Landeros Ayala, Director General Esteban Chavoya Bravo, Presidente José Solís Ramírez, Rector de la Universidad Autónoma de Chapingo Carlos Ricardo Menéndez Gámiz, IICA-México Moderador: Dr. Alfredo Camhaji Samra (IRC) Mtra Imelda Torres Sandoval, UACH Carlos Ricardo Menéndez Gámiz, IICA Gerardo Gómez González, UACH Refugio Tobar Reyes, Delia Morenos Velázquez, Ana Liviere Varhas Vizuet, Carlos Alberto Lobato Tapia, BUA México Felipe de Jesús Becerra-Guzmán, U. de G.-CUCSur Roxana Yuliet Espinoza-Rubio, Agropecuaria Roxana SPR Citlalli Arlae RojasLópez, Víctor Rubén Padilla Salas, U. de G. México Dra. Graciela Carrillo González, UAM Xochimilco, México Moderadora: Ing. Paula Medina Morales. (Biofábricas S XXI / Red Innovagro) Dr. Edgar Iván Roldán Cruz, CONACYT Hugo Alexander Chavarría Miranda, IICA Ing. Rosemberg Pérez, Dr. Carlos Ricardo Menéndez Gámiz, IICA México Dr. José Joaquín Díaz Solano, AGRIcircle Tekmann Ing. Francisco Ramírez y Ramírez, DGSV/SENASICA/SADER Ing. Agr. Aranzazú Aguilar FríasA discutir: Promover los principales elementos conceptuales y de aplicación práctica en torno a la bioeconomía circular en América, Europa y México que sirva de marco para coadyuvar al diseño de una estrategia nacional que atienda los principales retos y oportunidades nacionales para la seguridad alimentaria, la reactivación socio económica y la adaptación al cambio climático

Gender differences and management of stroke risk of nonvalvular atrial fibrillation in an upper middle-income country: Insights from the CARMEN-AF registry

Background: Atrial Fibrillation (AF) is associated with an increased risk of stroke and systemic embolism. Several studies have suggested that female AF patients could have a greater risk for stroke. There is scarce information about clinical characteristics and use of antithrombotic therapies in Latin American patients with nonvalvular AF. Objective: To describe the gender differences in clinical characteristics, thromboembolic risk, and antithrombotic therapy of patients with nonvalvular AF recruited in Mexico, an upper middle-income country, into the prospective national CARMEN-AF Registry. Methods: A total of 1423 consecutive patients, with at least one thromboembolic risk factor were enrolled in CARMEN-AF Registry during a three-year period (2014–2017). They were categorized according to Gender. Results: Overall, 48.6% were women, mean age 70 ± 12 years. Diabetes, smoking, alcoholism, non-ischemic cardiomyopathy, coronary artery disease, and obstructive sleep apnea were higher in men. Most women were found with paroxysmal AF (40.6%), and most men with permanent AF (44.0%). No gender differences were found in the use of vitamin K antagonists (VKA) (30.5% in women vs. 28.0% in men). No gender differences were found in the use of direct oral anticoagulants (DOAC) (33.8% women vs 35.4% men). Conclusions: CARMEN-AF Registry demonstrates that in Mexico, regardless of gender, a large proportion of patients remain undertreated. No gender differences were found in the use of VKA or DOAC. Keywords: Atrial fibrillation, Gender, Thromboembolic risk, Antithrombotic therapy, Stroke, Mexic

Compilación de Proyectos de Investigacion de 1984-2002

Instituto Politecnico Nacional. UPIICS

Table_1_Evidence of spatial clustering of childhood acute lymphoblastic leukemia cases in Greater Mexico City: report from the Mexican Inter-Institutional Group for the identification of the causes of childhood leukemia.xlsx

BackgroundA heterogeneous geographic distribution of childhood acute lymphoblastic leukemia (ALL) cases has been described, possibly, related to the presence of different environmental factors. The aim of the present study was to explore the geographical distribution of childhood ALL cases in Greater Mexico City (GMC).MethodsA population-based case-control study was conducted. Children ResultsA total of 1054 cases with ALL were analyzed. Of these, 408 (38.7%) were distributed across eight SCs detected. A relative risk of 1.61 (pConclusionsThe identification of SCs in certain regions of GMC suggest the possible role of environmental factors in the etiology of childhood ALL.</p

DataSheet_2_NK cells with decreased expression of multiple activating receptors is a dominant phenotype in pediatric patients with acute lymphoblastic leukemia.docx

NK cells have unique attributes to react towards cells undergoing malignant transformation or viral infection. This reactivity is regulated by activating or inhibitory germline encoded receptors. An impaired NK cell function may result from an aberrant expression of such receptors, a condition often seen in patients with hematological cancers. Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer worldwide and NK cells have emerged as crucial targets for developing immunotherapies. However, there are important gaps concerning the phenotype and behavior of NK cells during emergence of ALL. In this study we analyze the phenotype and function of NK cells from peripheral blood in pediatric patients with ALL at diagnosis. Our results showed that NK cells exhibited an altered phenotype highlighted by a significant reduction in the overall expression and percent representation of activating receptors compared to age-matched controls. No significant differences were found for the expression of inhibitory receptors. Moreover, NK cells with a concurrent reduced expression in various activating receptors, was the dominant phenotype among patients. An alteration in the relative frequencies of NK cells expressing NKG2A and CD57 within the mature NK cell pool was also observed. In addition, NK cells from patients displayed a significant reduction in the ability to sustain antibody-dependent cellular cytotoxicity (ADCC). Finally, an aberrant expression of activating receptors is associated with the phenomenon of leukemia during childhood.</p