Científicos jóvenes y sonrientes : la imagen de científico de los estudiantes chilenos de 11° y 12° grado en diferentes contextos escolares

Con el objetivo de conocer la imagen que estudiantes secundarios chilenos de diferentes contextos escolares (privado, público, subvencionado) tienen acerca de los científicos, es que se aplicó a una muestra de 438 estudiantes de 11. y 12.grado de la Región de Valparaíso (Chile) el Draw a Scientist Test (DAST; Chambers, 1983). Para el análisis se utilizaron criterios propuestos en la literatura, además de criterios levantados por el equipo de investigación. Los resultados muestran una imagen altamente estereotipada de científico (varones de raza blanca que trabajan solos y dentro de un laboratorio, usan delantal y gafas), además de algunos indicadores alternativos, como científicos jóvenes y sonrientes. Contrario a lo que describe la literatura, no se encontraron diferencias significativas entre tipos de establecimiento, salvo en algunos indicadores alternativos

Evaluation of the efficacy and safety of text messages targeting adherence to cardiovascular medications in secondary prevention: the txt2heart Colombia randomised controlled trial (Preprint)

Background: Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of mortality in the world. Prevalence is estimated at around 100 million patients worldwide. There is evidence that antiplatelet agents and antihypertensive medication reduce the risk of new vascular events in this population, but treatment adherence is very low. Objective: We developed an intervention based on behavioral modification techniques delivered via mobile short message services (SMS) to increase the adherence to pharmacologic treatment on patients with prior history of ASCVD. Methods: We conducted a randomized controlled clinical trial for patients with a prior diagnosis of cardiovascular event such as acute myocardial infarction, unstable angina, cerebrovascular disease or peripheral artery disease in one centre in Colombia. Patients randomized to the intervention arm were assigned to receive SMS daily for the first 4 weeks, five SMS on week 5: three SMS per week from week 6, and one SMS from 8th week until 52nd week. Patients in the control arm received a monthly SMS reminding them of the next study appointment, requesting information about changes in phone number, thanking them for participating in the study and reminding them of the importance of the study. Primary endpoint was change in Low Density Lipoprotein-Cholesterol (LDL-C) and the secondary endpoints were change in thromboxane B2 levels, heart rate, systolic and diastolic blood pressure. Medication adherence was measured with the Medication Adherence Report Scale (MARS 5), mortality and new cardiac hospitalization were assessed at one year end point. A logistic regression analysis and bivariate testing was performed. Results: Nine hundred and thirty patients were randomized, 805 (87%) completed follow up, and were analyzed for the primary endpoint. There was no difference between arms in change of LDL-C at 12 months (P=.41). or for any of the secondary outcomes. No adverse events were reported. Conclusions: In our study we did not find evidence that a behavior modification intervention delivered by SMS improved LDL-C, blood pressure levels or adherence at 12 months. More research is needed to evaluate whether different SMS strategies including personalized messages and with different timing are effective; future studies should include mixed methods to understand better why, for whom and in which context (e.g. health system, social environment) SMS interventions work (or not) to improve adherence in patients with ASCVD. Clinical Trial: Clinicaltrial.gov NCT03098186. Date of registration: March 31st 201

The endothelial glycocalyx prefers albumin for evoking shear stress-induced, nitric oxide-mediated coronary dilatation

Background: Shear stress induces coronary dilatation via production of nitric oxide ( NO). This should involve the endothelial glycocalyx ( EG). A greater effect was expected of albumin versus hydroxyethyl starch ( HES) perfusion, because albumin seals coronary leaks more effectively than HES in an EG-dependent way. Methods: Isolated hearts ( guinea pigs) were perfused at constant pressure with Krebs-Henseleit buffer augmented with 1/3 volume 5% human albumin or 6% HES ( 200/0.5 or 450/0.7). Coronary flow was also determined after EG digestion ( heparinase) and with nitro-L-arginine ( NO-L-Ag). Results: Coronary flow ( 9.50 +/- 1.09, 5.10 +/- 0.49, 4.87 +/- 1.19 and 4.15 +/- 0.09 ml/ min/ g for `albumin', `HES 200', `HES 450' and `control', respectively, n = 5-6) did not correlate with perfusate viscosity ( 0.83, 1.02, 1.24 and 0.77 cP, respectively). NO-L-Ag and heparinase diminished dilatation by albumin, but not additively. Alone NO-L-Ag suppressed coronary flow during infusion of HES 450. Electron microscopy revealed a coronary EG of 300 nm, reduced to 20 nm after heparinase. Cultured endothelial cells possessed an EG of 20 nm to begin with. Conclusions: Albumin induces greater endothelial shear stress than HES, despite lower viscosity, provided the EG contains negative groups. HES 450 causes some NO-mediated dilatation via even a rudimentary EG. Cultured endothelial cells express only a rudimentary glycocalyx, limiting their usefulness as a model system. Copyright (c) 2007 S. Karger AG, Basel

The cluster gas mass fraction as a cosmological probe: a revised study

(Abriged) We present the analysis of the baryonic content of 52 X-ray luminous galaxy clusters observed with Chandra in the redshift range 0.3-1.273. We use the deprojected X-ray surface brightness profiles and the measured values of the gas temperature to recover the gas and total mass profiles. By assuming that galaxy clusters are representative of the cosmic baryon budget, the distribution of the cluster baryon fraction in the hottest (T> 4 keV) systems as a function of redshift is used to constrain the cosmological parameters. We discuss how our constraints are affected by several systematics, namely the isothermality, the assumed baryon fraction in stars, the depletion parameter and the sample selection. By using only the cluster baryon fraction as a proxy for the cosmological parameters, we obtain that Omega is very well constrained at the value of 0.35 with a relative statistical uncertainty of 11% (1 sigma level; w=-1) and a further systematic error of about (-6,+7)%. On the other hand, constraints on Lambda (without the prior of flat geometry) and w (using the prior of flat geometry) are definitely weaker due to the presence of larger statistical and systematic uncertainties (of the order of 40 per cent on Lambda and larger than 50 per cent on w). If the WMAP 5-year best-fit results are assumed to fix the cosmological parameters, we limit the contributions expected from non-thermal pressure support and ICM clumpiness to be lower than about 10 per cent, leaving also room to accommodate baryons not accounted for either in the X-ray emitting plasma or in stars of the order of 18 per cent of the total cluster baryon budget.Comment: A&A in press. Accepted on March 28, 2009. Revised to match version in prin

Interstitial lung disease and anti-myeloperoxidase antibodies: Not a simple association

Anti-neutrophil cytoplasmic antibodies (ANCA), mainly anti-myeloperoxidase (MPO) antibodies, have been frequently identified in patients with idiopathic pulmonary fibrosis (IPF). However, their role remains unclear, and only 7–23% of these patients develops clinically overt vasculitis. We aimed to investigate the clinical, serological, and radiological features and prognosis of anti-MPO-positive interstitial lung disease (ILD) patients. Fifty-eight consecutive patients firstly referred for idiopathic interstitial pneumonia and showing serological positivity of anti-MPO antibodies were retrospectively enrolled. For each patient, clinical data, lung function testing, chest high-resolution computed tomography (HRCT) pattern, and survival were recorded. Thirteen patients developed a rheumatic disease during a median follow-up of 39 months. Usual interstitial pneumonia (UIP) was the most frequent ILD pattern, significantly influencing the patients’ survival. In fact, while the 52-week survival of the overall population was 71.4 ± 7.5%, significantly higher than IPF, survivals of anti-MPO patients with UIP pattern and IPF were similar. Forced vital capacity and diffusion lung capacity for CO significantly declined in 37.7 and 41.5% of cases, respectively, while disease progression at chest HRCT was observed in 45.2%. A careful clinical history and evaluation should always be performed in ILD patients with anti-MPO antibodies to quickly identify patients who are developing a systemic rheumatic disease

Robustness of a discrete-time predictor-based controller for time-varying measurement delay

A predictor-based controller for time-varying delay systems is presented in this paper and its robustness properties for different uncertainties are analyzed. First, a time-varying delay dependent stability condition is expressed in terms of LMIs. Then, uncertainties in the knowledge of all plant-model parameters are considered and the resulting closed-loop system is shown to be robust with respect to these uncertainties. A significant improvement with respect to the same control strategy without predictor is achieved. The scheme is applicable to open-loop unstable plants and it has been tested in a real-time application to control the roll angle of a quad-rotor helicopter prototype. The experimental results show good performance and robustness of the proposed scheme even in the presence of long delay uncertainties. © 2011 Elsevier Ltd.This work has been partially granted by Conselleria de Educacion under PROMETEO project number 2008-088, and CICYT no. DPI2008-06737-C02-01 from Spanish government.Gonzalez, A.; García Gil, PJ.; Albertos Pérez, P.; Castillo, P.; Lozano, R. (2012). Robustness of a discrete-time predictor-based controller for time-varying measurement delay. Control Engineering Practice. 20(2):102-110. https://doi.org/10.1016/j.conengprac.2011.09.001S10211020

Periodontitis and Cardiovascular Diseases. Consensus Report

Background: In Europe cardiovascular disease (CVD) is responsible for 3.9 million deaths (45% of deaths), being ischaemic heart disease, stroke, hypertension (leading to heart failure) the major cause of these CVD related deaths. Periodontitis is also a chronic non-communicable disease (NCD) with a high prevalence, being severe periodontitis, affecting 11.2% of the world's population, the sixth most common human disease. Material and Methods: There is now a significant body of evidence to support independent associations between severe periodontitis and several NCDs, in particular CVD. In 2012 a joint workshop was held between the European Federation of Periodontology (EFP) and the American Academy of Periodontology to review the literature relating periodontitis and systemic diseases, including CVD. In the last five years important new scientific information has emerged providing important emerging evidence to support these associations. Results and Conclusions: The present review reports the proceedings of the workshop jointly organised by the EFP and the World Heart Federation (WHF), which has updated the existing epidemiological evidence for significant associations between periodontitis and CVD, the mechanistic links and the impact of periodontal therapy on cardiovascular and surrogate outcomes. This review has also focused on the potential risk and complications of periodontal therapy in patients on anti thrombotic therapy and has made recommendations for dentists, physicians and for patients visiting both the dental and medical practices