Dynamics of a micro-electro-mechanical system associated with an atomic force microscope considering squeeze film damping.

In the following paper, we present a nonlinear model of an atomic force microscope considering the potential of Lennard-Jones and the nonlinear friction produced by the squeeze film damping effect, between the cantilever and the sample. Specifically, we study the existence and stability of periodic solutions using the lower and upper solution method in the system without friction. The condition for persistence of the homocline orbit was established by Melnikov method when the model has nonlinear friction. In this sense, the analytic and numerical approach is presented to verify the solutions of the model.

Accelerated imaging with segmented 2D pulses using parallel imaging and virtual coils.

Large magnetic field inhomogeneity can be a significant cause of spatial flip-angle variation when using ordinary, limited-bandwidth RF pulses. Multidimensional RF pulses are particularly sensitive to inhomogeneity due to their extended pulse length, which decreases their bandwidth. Previously, it was shown that, by breaking a 2D pulse into multiple undersampled k-space segments, the excitation bandwidth can be increased at the expense of increased imaging time. The present study shows how this increased imaging time can be offset by undersampling acquisition k-space in a phase-encoded dimension that is in the direction of excitation segmentation. Data from each segment are viewed as originating from "virtual receive coils" rather than multiple physical coils. The undersampled data are reconstructed using parallel imaging techniques (e.g. as in GRAPPA). The method was tested in vivo with brain imaging at both 3 T and 4 T, and used in conjunction with a 32-channel head coil and conventional GRAPPA on the 3 T data. Relationships with existing techniques and future applications are discussed.

Prevalencia de exceso de peso y su asociación con el consumo de frutas en trabajadores de la industria avícola en Bucaramanga, Colombia / Prevalence of excess weight and its association with fruits intake in poultry industry workers in Bucaramanga, Colombia

Introducción: El mundo experimenta una creciente epidemia de exceso de peso. Los contextos laborales representan escenarios aptos para la implementación de estrategias dirigidas hacia la promoción de estilos de vida saludables en los trabajadores. Objetivos: Determinar la prevalencia de exceso de peso y sus factores asociados en trabajadores del sector avícola. Métodos: Estudio de corte transversal analítico que incluyó trabajadores del sector de producción avícola en Bucaramanga, Colombia. La variable dependiente de este estudio fue la presencia de exceso de peso (sobrepeso u obesidad: Índice de Masa Corporal, IMC, ≥ 25 kg/m2). Se realizaron análisis bivariados y multivariantes para establecer razones de prevalencia (RP) mediante el uso de modelos de regresión binomial. Resultados: La prevalencia de exceso de peso fue 47.37%, IC 95%: 40.73% a 54.06%. El factor que resultó asociado con la presencia de exceso de peso fue: no haber consumido frutas en el último mes (RP: 1.76, IC 95%: 1.50 - 2.05) ajustado por sexo, edad y nivel socioeconómico. Discusión: La evidencia actual no es definitiva. Realizar estudios se hace necesario para determinar si el consumo de frutas y verduras podría tener algún impacto en el exceso de peso de grupos específicos de individuos. Conclusiones: Se encontró una alta prevalencia de exceso de peso y este evento se le asocio el hecho de no haber consumido frutas durante el último mes (AU)

Introduction: The world is experiencing a growing epidemic of overweight. Labor contexts represent scenarios suitable for the implementation of strategies aimed at promoting healthy lifestyles in workers. Objectives: Determine the prevalence of excess weight and its associated factors in poultry industry workers. Methods: An analytical cross sectional study that included industrial workers of poultry production in Bucaramanga, Colombia was carried out. The dependent variable of this study was the presence of overweight or obese (Body Mass Index, BMI ≥ 25 kg / m2). Both bivariate and multivariate analyzes were performed to establish prevalence ratios (PR) using binomial regression models. Results: The prevalence of overweight or obesity was 47.37%, CI 95%: 40.73% to 54.06%. Risk factor that was associated with the presence of overweight or obese: not having consumed fruits in the last month (PR: 1.76; CI 95%: 1.50 - 2.05), adjusted for sex, age and socioeconomic status. Discussion: The current evidence is not definitive. To realize studies is necessary to determine if the fruit and vegetables intake would have impact on excess weight in specific groups. Conclusions: Was found a high prevalence of excess weight and this event was associated with no consumption of fruits during last month (AU)

Síndrome de burnout en estudiantes de medicina pertenecientes a sociedades científicas peruanas: un estudio multicéntrico / Burnout syndrome in medical students belonging to Peruvian scientific societies: A multicenter study

Identificar la frecuencia de síndrome de burnout (SBO) en los estudiantes de Medicina pertenecientes a sociedades científicas peruanas en el 2015. Material y Métodos: Estudio observacional, descriptivo y transversal. La población estudiada fueron todos los estudiantes de medicina humana pertenecientes a 9 sociedades científicas de diferentes departamentos del Perú y afiliadas a la Sociedad Científica Médica Estudiantil Peruana (SOCIMEP). La recolección de datos fue a través de un cuestionario para datos biográficos y el Maslach Burnout Inventory. Resultados: Se encuestó a 158 estudiantes de medicina humana pertenecientes a 9 sociedades científicas peruanas. El 24,1 % tuvo un nivel severo de agotamiento emocional, el 45,6% un nivel severo de despersonalización, el 25,3% un nivel bajo de realización personal y 57,6% tuvieron SBO. El 60,8% de los estudiantes se encontraba realizando algún trabajo de investigación y el 49,4% ocupaba algún cargo en su sociedad científica. Conclusiones: Se identificó una importante frecuencia de SBO en los estudiantes de Medicina pertenecientes a las sociedades científicas estudiadas...

To identify the frequency of burnout syndrome (BOS) in medical students belonging to Peruvian scientific societies (2015). Material and Methods: It is an observational, descriptive and transversal study. The study population was all students of human medicine belonging to 9 scientific societies involving different departments of Peru and affiliated to the Sociedad Científica Médica Estudiantil Peruana (SOCIMEP). The data collection was through a biographical data questionnaire and the Maslach Burnout Inventory. Results: We surveyed 158 students of Human Medicine belonging to 9 Peruvian scientific societies. The 24.1% had a severe emotional exhaustion level, 45.6% a severe level of depersonalization, 25.3% reported low level of personal accomplishment, and 57.6% had BOS. The 60.8% of students were doing some research and 49.4% occupied a position in the scientific society. Conclusions: An important frequency of BOS was identified in the medical students belonging to scientific societies of the study...

Effect of Right-Sided Versus Left-Sided Contrast Injection on Intra-arterial Opacification Characteristics of Head and Neck Computed Tomography Angiograms and Interactions With Patient Sex, Weight, and Cardiac Output.

OBJECTIVE: The aims of this study were to support the standard clinical assumption that preferential right-sided injection (RSI) over left-sided injection (LSI) results in improved head and neck computed tomography angiograms and to determine which patients most benefit from RSIs. METHODS: Head and neck computed tomography angiograms of 453 RSIs and 419 LSIs were included. Interactions between injection side, age, weight, body mass index, and left ventricular ejection fraction with mean vessel Hounsfield units (HU) were compared. Statistical analysis was performed using 2-tailed Student t tests, Mann-Whitney U tests, and simple linear (SL) and multiple linear regressions. RESULTS: Right-sided injection yielded higher HU for patients older than 40 years (eg, RSI of the right common carotid artery [RCCA] vs LSI of the RCCA; P < 0.01). Body mass index (eg, RCCA; r = -0.31, P < 0.01 [SL]) and weight (eg, RCCA; r = -0.39, P < 0.01 [SL]) were negatively correlated with HU. Female had higher HU (mean ± SE, +39.7 ± 7.6 HU; P < 0.01 [multiple linear]). Left ventricular ejection fraction had no interactions with injection side or HU. CONCLUSIONS: The findings support preferential RSI in patients older than 40 years with higher body mass index and weight, particularly male.

3-Benzyl-2-(4-fluorophenyl)-1,3-thiazolidin-4-one.

The title compound, C(16)H(14)FNOS, crystallizes with Z' = 2 in the space group P2(1)/c. In one of the two independent molecules, the heterocyclic ring is effectively planar, but in the other molecule this ring adopts an envelope conformation. The molecules are weakly linked by two C-H···O hydrogen bonds to form C(2)(2)(14) chains. Comparisons are made with some symmetrically substituted 2-aryl-3-benzyl-1,3-thiazolidin-4-ones.

Fungicide activity of 5-(4-chlorobenzylidene)-(Z)-2-dimethylamino-1,3-thiazol-4-one against Cryptococcus neoformans.

The present work describes the synthesis and antifungal evaluation of new 5-arylidene-(Z)-2-dimethylamino-1,3-thiazol-4-ones 4a-f, obtained by the reaction of aromatic aldehydes 1 and rhodanine 2 followed by treatment with DMF. All compounds were tested against a panel of yeasts, hialohyphomycetes, and dermatophytes using the microbroth dilution method. Compounds 4a and 4c showed antifungal activity, with compound 4a being the most active one. Compound 4a demonstrated to be fungicidal rather than fungistatic and selective activity against Cryptococcus neoformans and dermatophytes. MIC(100), MIC(80), and MIC(50) of 4a were determined against a panel of clinical isolates of C. neoformans showing ranges of MICs between 2 and 16 microg/mL.