190 research outputs found

    Influencia del contenido de impurezas sobre la densidad y viscosidad de fluidos oleosos

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    In this work, as a case study, the measurement of the density (ρ) and the dynamic viscosity (µ) of 12 different fluids (taken from a conventional oil mill) has been carried out. The variability of the samples processed shows that their impurity contents c (between 0.5-5.87%), together with the temperature t (which varied between 20-30 ºC), can affect the values of ρ and µ. However, this variation has been shown to be different depending on the case, being of the order of 1% for density or even more than 50% for dynamic viscosity. The fact that µ can be sensitive to the presence of impurities opens up a line of study that could be used to estimate such impuritiy content, in real time, by means of relatively simple methods.En este trabajo, como caso de estudio, se ha llevado a cabo la medida de la densidad (ρ) y de la viscosidad dinámica (µ) de 12 fluidos diferentes tomados de una almazara convencional. La variabilidad de las muestras procesadas indica que el contenido de impurezas c (entre el 0,5%-5,87 %), junto con la temperatura t (que varió nominalmente entre 20 ºC-30 ºC), pueden afectar a los valores de ρ y µ. Sin embargo, esta variación se ha mostrado diferente dependiendo del caso, siendo del orden del 1 % para la densidad o incluso mayor del 50% para la viscosidad dinámica. El hecho de que µ pueda ser sensible a la presencia de impurezas abre una línea de estudio que podría ser aprovechada para estimar tal contenido de impurezas, en tiempo real, por medio de métodos relativamente sencillos

    Epithermal neutron beams from the 7Li(p,n) reaction near the threshold for neutron capture therapy

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    Two applications for neutron capture therapy of epithermal neutron beams calculated from the 7Li(p,n) reaction are discussed. In particular, i) for a proton beam of 1920 keV of a 30 mA, a neutron beam of adequate features for BNCT is found at an angle of 80◦ from the forward direction; and ii) for a proton beam of 1910 keV, a neutron beam is obtained at the forward direction suitable for performing radiobiology experiments for the determination of the biological weighting factors of the fast dose component in neutron capture therapy

    The inflammatory potential of diet is related to incident frailty and slow walking in older adults

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    Background: Certain foods and dietary patterns have been associated with both inflammation and frailty. As chronic inflammation may play a role in frailty and disability, we examined the association of the inflammatory potential of diet with these outcomes. Methods: Data were taken from 1948 community-dwelling individuals =60 years old from the Seniors-ENRICA cohort, who were recruited in 2008–2010 and followed-up through 2012. Baseline diet data, obtained with a validated diet history, was used to calculate Shivappa's Dietary Inflammatory Index (DII), an “a priori” pattern score which is based on known associations of foods and nutrients with inflammation, and Tabung's Empirical Dietary Inflammatory Index (EDII), an “a posteriori” pattern score which was statistically derived from an epidemiological study. At follow-up, incident frailty was assessed with Fried's criteria, and incident limitation in instrumental activities of daily living (IADL) with the Lawton-Brody index. Statistical analyses were performed with logistic regression, and adjusted for the main confounders. Results: Compared with individuals in the lowest tertile of DII, those in the highest tertile showed higher risk of frailty (odds ratio [OR] 2.48; 95% confidence interval [CI]: 1.42, 4.44, p-trend = 0.001) and IADL disability (OR: 1.96; 95% CI: 1.03, 3.86, p-trend = 0.035). By contrast, EDII did not show an association with these outcomes. The DII score was associated with slow gait speed, both as a low score in the Short Physical Performance Battery test (OR: 1.82; 95% CI: 1.27, 2.62, p-trend = 0.001) and as a positive Fried's criterion (OR: 1.64; 95% CI: 1.08, 2.51, p-trend = 0.021), which use different thresholds. Conclusions: DII predicted frailty and IADL while EDII did not. DII is able to measure diet healthiness in terms of physical decline in addition to avoidance of inflammation

    Stability in community-acquired pneumonia: one step forward with markers?

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    Background: Biological markers as an expression of systemic inflammation have been recognised as useful for evaluating the host response in community-acquired pneumonia (CAP). The objective of this study was to evaluate whether the biological markers procalcitonin (PCT) and C-reactive protein (CRP) might reflect stability after 72 h of treatment and the absence of subsequent severe complications. Methods: A prospective cohort study was performed in 394 hospitalised patients with CAP. Clinical stability was evaluated using modified Halm's criteria: temperature (37.2uC; heart rate (100 beats/min; respiratory rate (24 breaths/min; systolic blood pressure >90 mm Hg; oxygen saturation >90%; or arterial oxygen tension >60 mm Hg. PCT and CRP levels were measured on day 1 and after 72 h. Severe complications were defined as mechanical ventilation, shock and/or intensive care unit (ICU) admission, or death after 72 h of treatment. Results: 220 patients achieved clinical stability at 72 h and had significantly lower levels of CRP (4.2 vs 7 mg/dl) and of PCT (0.33 vs 0.48 ng/ml). Regression logistic analyses were performed to calculate several areas under the ROC curve (AUC) to predict severe complications. The AUC for clinical stability was 0.77, 0.84 when CRP was added (p=0.059) and 0.77 when PCT was added (p=0.45). When clinical stability was achieved within 72 h and marker levels were below the cut-off points (0.25 ng/ml for PCT and 3 mg/dl for CRP), no severe complications occurred. Conclusions: Low levels of CRP and PCT at 72 h in addition to clinical criteria might improve the prediction of absence of severe complications

    Continuous positive airway pressure (CPAP) in nonapneic asthma: A clinical review of current evidence

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    © 2020 by Turkish Thoracic Society-. The use of continuous positive airway pressure (CPAP) in asthma has been a point of debate over the past several years. Various studies, including those on animals and humans have attempted to understand the role and pathophysiology of CPAP in patients with either well controlled or poorly controlled asthma. The aim of this manuscript is to review the currently available literature on the physiologic and clinical effects of CPAP in animal models of asthma and on humans with stable asthma

    Selenium and impaired physical function in US and Spanish older adults

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    Background: Selenium (Se) is a trace element with a narrow safety margin. Objectives: To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and measures of impaired physical function and disability in older adults. Design: NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019 cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed. Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lowerextremity performance was assessed with the Short Physical Performance Battery, and muscle weakness with a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living (IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders, including physical activity. Results across studies were pooled using random-effects meta-analysis. Results: Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54 (0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13), and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a 2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness [odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32; 1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations. Discussion: In US and Spanish older adults, Se concentrations were inversely associated with physical function limitations. Further studies are needed to elucidate underlying mechanisms.Instituto de Salud Carlos III European Commission PI18/287 16/609State Secretary of R + D + I PID2019-108973RB-C21/C22European Social Fund (ESF) European Commissio
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