Theoretical–Experimental Study of the Action of Trace Amounts of Formaldehyde, Propionaldehyde, and Butyraldehyde as Inhibitors of the Ziegler–Natta Catalyst and the Synthesis of an Ethylene–Propylene Copolymer

The copolymer synthesis process can be affected by failures in the production process or by contaminating compounds such as ketones, thiols, and gases, among others. These impurities act as an inhibiting agent of the Ziegler–Natta (ZN) catalyst affecting its productivity and disturbing the polymerization reaction. In this work, the effect of formaldehyde, propionaldehyde,and butyraldehyde on the ZN catalyst and the way in which it affects the final properties of the ethylene-propylene copolymer is presented by analyzing 30 samples with different concentrations of the mentioned aldehydes along with three control samples. It was determined that the presence of formaldehyde 26 ppm, propionaldehyde 65.2 ppm, and butyraldehyde 181.2 ppm considerably affect the productivity levels of the ZN catalyst; this effect increases as the concentration of aldehydes is higher in the process; likewise, these impurities affect the properties of the final product, such as the fluidity index (MFI), thermogravimetric analysis (TGA), bending, tension, and impact, which leads to a polymer with low-quality standards and less resistance to breakage. The computational analysis showed that the complexes formed by formaldehyde, propionaldehyde, and butyraldehyde with the active center of the catalyst are more stable than those obtained by the ethylene-Ti and propylene-Ti complexes, presenting values of −40.5, −47.22, −47.5, −5.2 and −1.3 kcal mol−1 respectively

Cardiorespiratory Fitness and Fatness Are Associated With Health Complaints and Health Risk Behaviors in Youth

We examined the association of cardiorespiratory fitness and fatness with health complaints and health risk behaviors in 691 (323 girls) Spanish children aged 6 to 17.9. Methods: Health complaints and health risk behaviors were self-reported using items of the Health Behavior in School-aged Children questionnaire. Weight and height were measured and body mass index was computed. Cardiorespiratory fitness was measured by the 20-m shuttle-run test, and youth categorized as fit/unfit. Results: Unfit youth were more likely to report health complaints sometime (OR: 2.556, 95% CI: 1.299–5.031; and OR: 1.997, 95% CI: 1.162–3.433, respectively) and health risk behaviors such as drinking alcohol sometime (OR: 5.142, 95% CI: 1.214–21.783; and OR: 2.413, 95% CI: 1.484–3.923) than their fit counterparts. Overweight-obese youth were more likely to report health complaints (OR: 1.732, 95% CI: 1.019–2.945; and OR: 1.983, 95% CI: 1.083–3.629, respectively). The analysis of the combined influence of fitness and fatness revealed that fit youth had lower health complaints index than the fat-unfit and unfat-unfit groups (all P < .05). Conclusions: Low fitness and overweight-obesity increased the risk of having health complaints in youth, yet high levels of cardiorespiratory fitness might overcome deleterious effects of overweight-obesity on health complaints

SEOM clinical guidelines for the treatment of malignant pleural mesothelioma (2020)

Mesothelioma is a rare and aggressive tumour with dismal prognosis arising in the pleura and associated with asbestos exposure. Its incidence is on the rise worldwide. In selected patients with early-stage MPM, a maximal surgical cytoreduction in combination with additional antitumour treatment may be considered in selected patients assessed by a multidisciplinary tumor board. In patients with unresectable or advanced MPM, chemotherapy with platinum plus pemetrexed is the standard of care. Currently, no standard salvage therapy has been approved yet, but second-line chemotherapy with vinorelbine or gemcitabine is commonly used. Novel therapeutic approaches based on dual immunotherapy or chemotherapy plus immunotherapy demonstrated promising survival benefit and will probably be incorporated in the future

Two heads are better than one, but how much? Evidence that people's use of causal integration rules does not always conform to normative standards.

Many theories of causal learning and causal induction differ in their assumptions about how people combine the causal impact of several causes presented in compound. Some theories propose that when several causes are present, their joint causal impact is equal to the linear sum of the individual impact of each cause. However, some recent theories propose that the causal impact of several causes needs to be combined by means of a noisy-OR integration rule. In other words, the probability of the effect given several causes would be equal to the sum of the probability of the effect given each cause in isolation minus the overlap between those probabilities. In the present series of experiments, participants were given information about the causal impact of several causes and then they were asked what compounds of those causes they would prefer to use if they wanted to produce the effect. The results of these experiments suggest that participants actually use a variety of strategies, including not only the linear and the noisy-OR integration rules, but also averaging the impact of several causes

Niveles de ansiedad en futbolistas de categorías inferiores

Due to the relationship between psychological variables and sports performance, sports psychology has gained special relevance in recent decades, so the present research aims to analyze the levels of anxiety in players of lower categories, using a Descriptive cross-sectional design on a sample of 156 teenage soccer players. For the collection of data, an ad-hoc questionnaire was used to record the sociodemographic variables and the Stai-Trait to measure anxiety levels. The results of this research indicate that six out of ten players show average levels of anxiety-state and three out of ten high, in terms of trait-anxiety, half have high anxiety and the other half. The main conclusion of this research is that the level of studies of footballers is related to levels of anxiety.Debido a la relación existente entre las variables psicológicas y el rendimiento deportivo, la psicología del deporte ha cobrado una especial relevancia en las últimas décadas, por lo que la presente investigación tiene como objetivo analizar los niveles de ansiedad en futbolistas de categorías inferiores, utilizando un diseño descriptivo de corte transversal sobre una muestra de 156 futbolistas adolescentes. Para la recogida de datos se ha utilizado un cuestionario ad-hoc para el registro de las variables sociodemográficas y el Stai-Rasgo para medir los niveles de ansiedad. Los resultados de la presente investigación indican que seis de cada diez futbolistas muestran niveles medios de ansiedad-estado y tres de cada diez alta, en cuanto a la ansiedad-rasgo, la mitad tienen una ansiedad alta y la otra mitad media. Como principal conclusión de esta investigación se extrae que el nivel de estudios de los futbolistas se relaciona con los niveles de ansiedad

Body composition changes after a weight loss intervention: A 3-year follow-up study

Studies comparing different types of exercise-based interventions have not shown a consistent effect of training on long-term weight maintenance. The aim of this study was to compare the effects of exercise modalities combined with diet intervention on body composition immediately after intervention and at 3 years’ follow-up in overweight and obese adults. Two-hundred thirty-nine people (107 men) participated in a 6-month diet and exercise-based intervention, split into four randomly assigned groups: strength group (S), endurance group (E), combined strength and endurance group (SE), and control group (C). The body composition measurements took place on the first week before the start of training and after 22 weeks of training. In addition, a third measurement took place 3 years after the intervention period. A significant interaction effect (group × time) (p = 0.017) was observed for the fat mass percentage. It significantly decreased by 5.48 ± 0.65%, 5.30 ± 0.65%, 7.04 ± 0.72%, and 4.86 ± 0.65% at post-intervention for S, E, SE, and C, respectively. Three years after the intervention, the fat mass percentage returned to values similar to the baseline, except for the combined strength and endurance group, where it remained lower than the value at pre-intervention (p &lt; 0.05). However, no significant interaction was discovered for the rest of the studied outcomes, neither at post-intervention nor 3 years later. The combined strength and endurance group was the only group that achieved lower levels of fat mass (%) at both post-intervention and 3 years after intervention, in comparison with the other groups.This work received financial support from the Ministerio de Ciencia e Innovación, Convocatoria de Ayudas I+D 2008, Proyectos de Investigación Fundamental No Orientada, del VI Plan de Investigación Nacional 2008–2011 (Contract: DEP2008-06354-C04-01). This study is registered at www.clinicaltrials.gov (ID: NCT0111685

LISA and LISA PathFinder, the endeavour to detect low frequency GWs

This is a review about LISA and its technology demonstrator, LISA PathFinder. We first describe the conceptual problems which need to be overcome in order to set up a working interferometric detector of low frequency Gravitational Waves (GW), then summarise the solutions to them as currently conceived by the LISA mission team. This will show that some of these solutions require new technological abilities which are still under development, and which need proper test before being fully implemented. LISA PathFinder (LPF) is the the testbed for such technologies. The final part of the paper will address the ideas and concepts behind the PathFinder as well as their impact on LISA.Comment: 25 pages, 21 figures, presented at the Spanish Relativity Meeting, Mallorca September 2006. Will be published in Journal of Physics: Conference Series, IOP. To be published in Journal of Physics: Conference Series, IO

Incompressible Fluids of the de Sitter Horizon and Beyond

There are (at least) two surfaces of particular interest in eternal de Sitter space. One is the timelike hypersurface constituting the lab wall of a static patch observer and the other is the future boundary of global de Sitter space. We study both linear and non-linear deformations of four-dimensional de Sitter space which obey the Einstein equation. Our deformations leave the induced conformal metric and trace of the extrinsic curvature unchanged for a fixed hypersurface. This hypersurface is either timelike within the static patch or spacelike in the future diamond. We require the deformations to be regular at the future horizon of the static patch observer. For linearized perturbations in the future diamond, this corresponds to imposing incoming flux solely from the future horizon of a single static patch observer. When the slices are arbitrarily close to the cosmological horizon, the finite deformations are characterized by solutions to the incompressible Navier-Stokes equation for both spacelike and timelike hypersurfaces. We then study, at the level of linearized gravity, the change in the discrete dispersion relation as we push the timelike hypersurface toward the worldline of the static patch. Finally, we study the spectrum of linearized solutions as the spacelike slices are pushed to future infinity and relate our calculations to analogous ones in the context of massless topological black holes in AdS$_4$.Comment: 27 pages, 8 figure