Effect of nitrogen ion irradiation on the nano-tribological and surface mechanical properties of ultra-high molecular weight polyethylene

Generation of wear debris is the principal obstacle limiting the durability of ultra-high molecular weight polyethylene (UHMWPE) in biomedical applications. Aiming to enhance UHMWPE wear resistance, surface modification with swift heavy ion irradiation (SHI) appears as a potential and attractive methodology. Contrary to ion implantation techniques, the swift heavy ions range can reach tens to hundreds microns and its extremely high linear energy is able to induce effective chemical modifications using low fluence values. Nano-wear performance and surface mechanical properties of samples of pristine and SHI irradiated (using N2+ ions at 33MeV and a fluence of 1×1012ions/cm2) were characterized by depth sensing indentation (DSI) and scanning probe microscopy (SPM). It turned out that modifications induced by irradiation at the surface layers were successful to reduce nano-wear volume and creep deformation. These improvements were related to beneficial changes in hardness, elastic modulus, hardness to elastic modulus ratio and friction coefficient.Fil: Fasce, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Cura, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: del Grosso, Mariela Fernanda. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garcia Bermudez, Gerardo Jose. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Frontini, Patricia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Determinación de constantes fisicoquímicas de humor vítreo de equinos

El humor vítreo es una sustancia transparente y gelatinosa, formada principalmente por agua, que se encuentra en la cavidad del ojo por detrás del cristalino, tratándose de un espacio avascular y cerrado. En medicina veterinaria, el análisis post-mortem de este líquido biológico puede servir para determinar diversos tipos de enfermedades metabólicas, renales y nutricionales.El objetivo del presente trabajo fue caracterizar el humor vítreo equino mediante la determinación de su densidad, viscosidad y tensión superficial, la concentración de proteínas, y los macrominerales Na, K, P, Ca y Mg. El humor vítreo fue obtenido de equinos sanos, sacrificados en el Frigorífico Indio Pampa. La densidad fue cuantificada a partir del método del picnómetro; el comportamiento reológico se estudió con el viscosímetro digital de rotación HAAKE,RS 600, y la tensión superficial mediante el método del anillo a partir del tensiómetro de Du Noüy Las proteínas totales fueron determinadas por un método colorimétrico, técnica PROTI U/LCR (Weiner LAB), al igual que el contenido de P (técnica Fosfatemia,Weiner LAB); en tanto, los contenidos de Ca y Mg se determinaron por espectrofotometría de absorción atómica y los de Na y K, por fotometría de llama. Los resultados de densidad, viscosidad y tensión superficial del líquido biológico estudiado a 20ºC fueron de 1.0025 g.cm-3, 2.13 cp y 51.0045 dinas.cm-1, respectivamente y presentaron una buena correlación lineal con respecto a la temperatura. Los contenidos de proteínas, P, Na, K, Ca y Mg resultaron ser de 0.033 g. dl-1, 1,1200 g. dl-1, 151.82 mEq.l-1, 3.7200 mEq.l- 1, 3.2125 mg dl-1 y 1.5379 mg dl-1, respectivamente. Se puede concluir que a partir de la caracterización postmortem de este fluído orgánico, se podrá inferir el estado de salud antemortem de los equinosThe humor vitreous is a transparent and gelatinous substance, composed primarily of water, which is located in the cavity of the eye behind the lens, in the case of an avascular area and closed. In veterinary medicine, the postmortem analysis of the biological liquid can be used to identify various types of metabolic diseases, kidney and nutrition..The objective of the present work was to characterize the vitreous equine by determining its density, viscosity and surface tension, the concentration of protein, Na, K, P,Ca and Mg.Vitreous humor was obtained from healthy horse, killed in the Fridge Indio Pampa.The density was quantified from the method of pycnometer; rheological behaviour was studied using the digital rotary viscometer HAAKE, RS 600, and surface tension tension by the method of the ring from tensiometer Du Noüy.Total proteins were determined by means of a quantitative colorimetric method, technique PROTI U/LCR (Weiner LAB.) at same that contents of P (technique Fosfatemia (Weiner LAB); while the contents of Ca and Mg were determined by atomic absorption spectrometry and its of Na and K, by flame photometry. Results obtained for density, viscosity and surface tension were 1.0025 g.cm-3, 2.13 cp y 51.0045 dinas.cm-1, respectively and showed a good linear correlation with respect to temperature.Facultad de Ciencias Veterinaria

A primary healthcare information intervention for communicating cardiovascular risk to patients with poorly controlled hypertension: The Education and Coronary Risk Evaluation (Educore) study-A pragmatic, cluster-randomized trial

PURPOSE: Uncertainty exists regarding the best way to communicate cardiovascular risk (CVR) to patients, and it is unclear whether the comprehension and perception of CVR varies according to the format used. The aim of the present work was to determine whether a strategy designed for communicating CVR information to patients with poorly controlled high blood pressure (HBP), but with no background of cardiovascular disease, was more effective than usual care in the control of blood pressure (BP) over the course of a year. METHODS: A pragmatic, two-arm, cluster-randomized controlled trial was performed. Consecutive patients aged 40-65 years, all diagnosed with HBP in the last 12 months, and all of whom showed poor control of their condition (systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg), were recruited at 22 primary healthcare centres. Eleven centres were randomly assigned to the usual care arm, and 11 to the informative intervention arm (Educore arm). At the start of the study, the Educore arm subjects were shown the "low risk SCORE table", along with impacting images and information pamphlets encouraging the maintenance of good cardiovascular health. The main outcome variable measured was the control of HBP; the secondary outcome variables were SCORE table score, total plasma cholesterol concentration, use of tobacco, adherence to prescribed treatment, and quality of life. RESULTS: The study participants were 411 patients (185 in the Educore arm and 226 in the usual care arm). Multilevel logistic regression showed that, at 12 months, the Educore intervention achieved better control of HBP (OR = 1.57; 1.02 to 2.41). No statistically significant differences were seen between the two arms at 12 months with respect to the secondary outcomes. CONCLUSIONS: Compared to usual care, the Educore intervention was associated with better control of HBP after adjusting for age, baseline SBP and plasma cholesterol, at 12 months.This study was funded by the Spanish Ministry of Science and Innovation via the Instituto de Salud Carlos III, Subprograma de Proyectos de Investigación en Evaluación de Tecnologías Sanitarias y Servicios de Salud (PI 09/90354), and the Fundación de Investigación e Innovación Biomédica en Atención Primaria (FIIBAP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptS