315 research outputs found
Fracture resistance and failure mode of posterior fixed dental prostheses fabricated with two zirconia CAD/CAM systems
Background: In recent years there has been an improvement of zirconia ceramic materials to replace posterior missing teeth. To date little in vitro studies has been carried out on the fracture resistance of zirconia veneered posterior
fixed dental prostheses. This study investigated the fracture resistance and the failure mode of 3-unit zirconia-based
posterior fixed dental prostheses fabricated with two CAD/CAM systems.
Material and Methods: Twenty posterior fixed dental prostheses were studied. Samples were randomly divided into
two groups (n=10 each) according to the zirconia ceramic analyzed: Lava and Procera. Specimens were loaded
until fracture under static load. Data were analyzed using Wilcoxon ́s rank sum test and Wilcoxon ́s signed-rank
test (
P
<0.05).
Results: Partial fracture of the veneering porcelain occurred in 100% of the samples. Within each group, significant
differences were shown between the veneering and the framework fracture resistance (
P
=0.002). The failure occurred in the connector cervical area in 80% of the cases.
Conclusions: All fracture load values of the zirconia frameworks could be considered clinically acceptable. The
connector area is the weak point of the restoration
Design of injection‐locked oscillator circuits using an HBT X‐parameters™‐based model
A load independent X-parameters-based heterojunction bipolar transistor (HBT) model has been used for the first time in the design and behaviour prediction of injection-locked oscillator circuits. This model has been extracted from load-pull measurements with a large-signal network analyser and, in order to obtain a high oscillator RF power, targeting a load impedance close to the optimum one for HBT maximum output power. A methodology is given to obtain robust injection-locked oscillator circuits with a high-synchronisation bandwidth. Several injection-locked oscillator prototypes have been designed and fabricated, and their measurements compared with the simulations obtained using the X-parameters model. Satisfactory results were obtained when the prototypes were operated as free-running and synchronised oscillators.Ministerio de Ciencia e Innovación | Ref. TEC2011-29264-C03-03Xunta de Galicia | Ref. 2012/26
Formulación de un plan de negocios para la creación de una empresa de alimentos orientados a satisfacer estilos de vida saludables
101 páginasThe proposed business plan was developed by the Lean Canvas methodology taking into account the aclual situation in the Externado University, due to, for the students and professors is difficult to fínd fast and healthy options for the lunch time. The model was propounded by the observation, market research, the implementation of a pilot test during 2017, the study of the healthy diet and thc strategices to reach the market positioning. The Canvas template was developed in order to recognize the characteristics and necessities of the market, attributes of the product, value proposal, distribution channels, financial analysis, among others.A partir de la carencia de restaurantes con opciones rápidas y saludables para los estudiantes y profesores de la Universidad Externado de Colombia, se propone el siguiente plan de negocios. Desarrollado con base en la metodología Lean Canvas y planteado a partir de la observación, investigación de mercados y puesta en marcha de una prueba piloto realizada durante el año 2017. Se identificó el contexto de la alimentación saludable y las estrategias que se deben aplicar para obtener el posicionamiento esperado en el mercado. Se desarrollaron cada uno de los componentes del Lean Canvas, obteniendo así: las necesidades y características del segmento de mercado, los atributos del producto que consolidan la propuesta de valor, los canales de distribución y el análisis financiero del proyecto, entre otros.Administrador(a) de Empresas Turísticas y HotelerasPregrad
Dependencia emocional y violencia en parejas: Revisión sistemática
La presente investigación sistemática analiza la Dependencia Emocional y
Violencia en Parejas, tuvo como objetivo general: analizar los factores asociados
a la dependencia emocional y violencia en parejas. Se realizó un tipo de
investigación teórico, con un diseño no experimental. La muestra estuvo
conformada por cincuenta y ocho artículos científicos, estos fueron de diferentes
orígenes, teniendo como resultado que predominan los factores psicológicos,
sociales y culturales. Los instrumentos más utilizados son el Cuestionario de
Dependencia Emocional (CDE) y El Conflict in Adolescent Dating Relationships
Inventory (CADRI)
Synthesis, anti-tuberculosis activity and QSAR study of 2,4-diarylquinolines and analogous polycyclic derivatives
The multicomponent syntheses of 2,4-di-aryl-quinolines and analogous polycyclic derivatives as anti-tuberculosis agents were described. They were prepared via Beyer and Friedländer methods under microwave irradiation in short reaction times and good yields. Several homogeneous and heterogeneous acid catalysts were compared for preparing 2,4-di-arylquinolines and among them trifluoroacetic acid (TFA) reached the higher yields. Two derivatives exhibited activity against Mycobacterium tuberculosis H37Rv (Mtb), underwent additional testing and were considered lead compounds. The synthesis of a series of polycyclic analogous led to six new active compounds and a Quantitative Structure Activity Relationship study (QSAR) study was established.Fil: Muscia, Gisela Celeste. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Carnevale, Juan Pablo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Luczywo, Ayelen. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Victoria Peláez, María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Rodríguez Ó Toole, Ailen. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Buldain, Graciela Yolanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Casal, Juan José. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Asís, Silvia Elizabeth. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentin
Alcohol use and family‑related factors among Spanish university students: the unHicos project
Background: During adolescence and youth there are relevant changes in the consolidation, gain or loss of consumption habits and lifestyles and the family factors has a fundamental role to development these habits. The study of the consumption of toxins, such as alcohol intake, is crucial at this stage due to the repercussions that said consumption presents in adulthood. Therefore, the objective of our study was to evaluate the associations between alcohol consumption patterns and related family factors (family functioning, family history of alcohol consumption) in Spanish university students. Methods: Observational, descriptive, cross-sectional, multicenter study, carried out in first-year university students from 11 Spanish universities. Through an online questionnaire, alcohol consumption (risky consumption and intensive consumption or binge drinking), family functioning and history of alcohol in the family were evaluated. Risky alcohol consumption and binge drinking were assessed using the AUDIT test, and family functioning was assessed using the family APGAR questionnaire. A descriptive analysis of the data was performed, as well as the Chi- Square test and Student’s T-Test, and non-conditional logistic regression models were carried out to examine this association. Results: The prevalence of risky alcohol consumption identified in the 10,167 respondents was 16.9% (95% CI = 16.2–17.6), and that of BD was 48.8% (95% CI = 47.9–48.8). There is a significant association between risky alcohol consumption and family functioning in students of both sexes, with greater consumption in the face of severe dysfunctional support (men OR = 1.72; p < 0.001 and women OR = 1.74; p < 0.001) and family history of consumption (p = 0.005). Regarding the binge drinking pattern, no statistically significant differences were observed. Conclusions: Risky alcohol consumption in university students is associated with dysfunctional family support, unlike the binge drinking pattern, where there is no such association. The findings of this study show the importance of creating prevention programs focused on the family approach in
university students, which include alcohol screening in the population with a family history of this substance, and
greater social support from health services.National Drug Plan, Ministry of Health, Social Services and Equality of Spain 2010|145
2013|034
PI16/0194
Enhancing safety in hyperbaric environments through analysis of autonomic nervous system responses: a comparison of dry and humid conditions
Diving can have significant cardiovascular effects on the human body and increase the risk of developing cardiac health issues. This study aimed to investigate the autonomic nervous system (ANS) responses of healthy individuals during simulated dives in hyperbaric chambers and explore the effects of the humid environment on these responses. Electrocardiographic- and heart-rate-variability (HRV)-derived indices were analyzed, and their statistical ranges were compared at different depths during simulated immersions under dry and humid conditions. The results showed that humidity significantly affected the ANS responses of the subjects, leading to reduced parasympathetic activity and increased sympathetic dominance. The power of the high-frequency band of the HRV after removing the influence of respiration, PHF⊥¯, and the number of pairs of successive normal-to-normal intervals that differ by more than 50 ms divided by the total number of normal-to-normal intervals, pNN50¯, indices were found to be the most informative in distinguishing the ANS responses of subjects between the two datasets. Additionally, the statistical ranges of the HRV indices were calculated, and the classification of subjects as “normal” or “abnormal” was determined based on these ranges. The results showed that the ranges were effective at identifying abnormal ANS responses, indicating the potential use of these ranges as a reference for monitoring the activity of divers and avoiding future immersions if many indices are out of the normal ranges. The bagging method was also used to include some variability in the datasets’ ranges, and the classification results showed that the ranges computed without proper bagging represent reality and its associated variability. Overall, this study provides valuable insights into the ANS responses of healthy individuals during simulated dives in hyperbaric chambers and the effects of humidity on these responses
¿Puede el ejercicio físico moderado durante el embarazo actuar como un factor de prevención de la Diabetes Gestacional? (Can moderate physical exercise during pregnancy act as a factor in preventing Gestational Diabetes?)
<p align="justify">The aim of the present study was to know the effectiveness of exercise of a moderate program developed during pregnancy in the excessive maternal weight gain and development of Gestational Diabetes (GD). We performed a clinical trial, randomized, unmatched, not masked by mean the collaboration between the Department of Gynecology and Obstetrics of Health Center of Torrelodones (Madrid) and the Polytechnic University of Madrid. 55 pregnant women without obstetric contraindications were studied, (age= 32,9±3,9 years), all of them caucasian, 25 in the treatment group and 30 in the control group. A physical exercise program was developed (land/water) three times per week during pregnancy. According to our resultats, treatment group showed a lower maternal weight gain than in the control group (12.820±3.682 g and 14.780 g ± 3.427 g respectively, p=0.03). The values in the O'Sullivan test are lower in the treatment group than in the control group (102,9±17,7 gr/dL vs 125,6±30,8 gr/dL respectively, p=0,002). Not diagnosed any cases of GD in the treatment group while the control group 2 cases were diagnosed. The exercise done during the pregnancy reduces maternal weight gain, values of O’Sullivan score and apparently acts as a preventive factor of the GD.</p>Resumen<p align="justify">El presente trabajo pretende conocer la eficacia de un programa de ejercicio f��sico moderado desarrollado durante todo el embarazo en la excesiva ganancia de peso materno y el desarrollo de la Diabetes Gestacional (DG). Se realizó un ensayo clínico, aleatorizado, no apareado, no enmascarado mediante una colaboración entre el Servicio de Ginecología y Obstetricia del Centro de Salud de Torrelodones y la Universidad Politécnica de Madrid. 55 gestantes sin contraindicaciones obstétricas fueron estudiadas, (edad=32,9±3,9 años), todas ellas caucásicas, 25 en el grupo de tratamiento y 30 en el de control. Se desarrolló un programa de ejercicio físico (seco/agua) durante todo el embarazo con una frecuencia de tres sesiones semanales. Nuestros resultados muestran que grupo de tratamiento presentó una menor ganancia de peso materno que en el de control (12.820±3.682 gr y 14.780±3.427 gr respectivamente, p=0,03), los valores en el Test de O´Sullivan (sobrecarga oral de glucosa) fueron inferiores en el grupo de tratamiento que en el de control 102,9±17,7 gr/dL vs 125,6±30,8 gr/dL respectivamente, p=0,002). No se diagnosticó ningún caso de DG en el grupo de tratamiento mientras que en el grupo de control se diagnosticaron 2 casos. El ejercicio físico desarrollado durante el embarazo reduce la ganancia de peso materno, los valores del Test de O’Sullivan y actúa aparentemente como un factor de prevención de la DG.</p
The effect of infant body mass on carrier travel speed in Cotton-top Tamarins (Saguinus oedipus)
Infant carrying is common in primates and may be the second most costly activity related to reproduction, after lactation. In cooperative breeding groups of callitrichids, all group members carry and care for twin infants. Previous studies have described the costs of infant carrying in terms of body mass loss and reduced locomotor capability. However, infant carrying may also influence travel speed, an important potential cost because slower speed may handicap foraging, energetic budgets, and predator avoidance. We evaluated the impact of infant carrying on the travel speed of 27 adult and 9 subadult cotton-top tamarins (Saguinus oedipus) of both sexes in large outdoor enclosures. We compared carrier speed to speed when not carrying during the 10 weeks after nine births. Subadult tamarins, which have a lower body mass than adults do, moved faster than adults when not carrying. We found no difference between the mean speeds of subadults and adults while carrying. However, the speed of carriers decreased as infant mass increased, and the slope of this negative relationship was more pronounced in subadult carriers. For every 80 g of extra mass load (the body mass of newborn twins), adults reduced their speed by 6 % and subadults by 19 % relative to noncarrying speed. We also observed a reduction in speed while carrying two infants in adult tamarins as carrying time increased. Our results contribute to an understanding of the costs of infant carrying, and serve to emphasize the importance of cooperative breeding systems in coping with these costsThe contract grant sponsor was the Spanish Ministerio de Ciencia e Innovación-Subdirección General de Proyectos de Investigación (contract grant no. PSI2009-08581PSIC
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