Breakdown of anomalous channeling with ion energy for accurate strain determination in gan-based heterostructures

The influence of the beam energy on the determination of strain state with ion channeling in GaN-based heterostructures (HSs) is addressed. Experimental results show that anomalous channeling may hinder an accurate analysis due to the steering effects at the HS interface, which are more intense at lower ion energies. The experimental angular scans have been well reproduced by Monte Carlo simulations, correlating the steering effects with the close encounter probability at the interface. Consequently, limitations in the determination of the strain state by ion channeling can be overcome by selecting the adequate beam energy

Thermoelectric properties of n-type poly (ether ether ketone)/carbon nanofiber melt-processed composites

The thermoelectric properties, at temperatures from 30 °C to 100 °C, of melt-processed poly(ether ether ketone) (PEEK) composites prepared with 10 wt.% of carbon nanofibers (CNFs) are discussed in this work. At 30 °C, the PEEK/CNF composites show an electrical conductivity (σ) of ~27 S m−1 and a Seebeck coefficient (S) of −3.4 μV K−1, which means that their majority charge carriers are electrons. The origin of this negative Seebeck is deduced because of the impurities present in the as-received CNFs, which may cause sharply varying and localized states at approximately 0.086 eV above the Fermi energy level (EF) of CNFs. Moreover, the lower S, in absolute value, found in PEEK/CNF composites, when compared with the S of as-received CNFs (−5.3 μV K−1), is attributed to a slight electron withdrawing from the external layers of CNFs by the PEEK matrix. At temperatures from 30 °C to 100 °C, the σ (T) of PEEK/CNF composites, in contrast to the σ (T) of as-received CNFs, shows a negative temperature effect, understood through the 3D variable-range hopping (VRH) model, as a thermally activated hopping mechanism across a random network of potential wells. Moreover, their nonlinear S (T) follows the same behavior reported before for polypropylene composites melt-processed with similar CNFs at the same interval of temperatures.A. J. Paleo gratefully acknowledges support from FCT-Foundation for Science and Technology by the project UID/CTM/00264/2021 of 2C2T under the COMPETE and FCT/MCTES (PIDDAC) cofinanced by FEDER through the PT2020 program and “plurianual” 2020–2023 Project UIDB/00264/2020. E. Muñoz acknowledges financial support from ANID Anillo ACT/192023 and Fondecyt No 1190361. M. Melle-Franco acknowledges support from the project IF/00894/2015 and within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC)

Telerehabilitation as a therapeutic exercise tool versus face-to-face physiotherapy: a systematic review

Digital physiotherapy, often referred to as “Telerehabilitation”, consists of applying rehabilitation using telecommunication technologies. The objective is to evaluate the effectiveness of therapeutic exercise when it is telematically prescribed. Methods: We searched PubMed, Embase, Scopus, SportDiscus and PEDro (30 December 2022). The results were obtained by entering a combination of MeSH or Emtree terms with keywords related to telerehabilitation and exercise therapy. RCTs on patients over 18 years and two groups were included, one working with therapeutic exercise through telerehabilitation and one working with conventional physiotherapy group. Results: a total of 779 works were found. However, after applying the inclusion criteria, only 11 were selected. Telerehabilitation is most frequently used to treat musculoskeletal, cardiac and neurological pathologies. The preferred telerehabilitation tools are videoconferencing systems, telemonitoring and online platforms. Exercise programs ranged from 10 to 30 min and were similar in both intervention and control groups. In all the studies, results proved to be similar for telerehabilitation and face-to-face rehabilitation in both groups when measuring functionality, quality of life and satisfaction. Conclusion: this review generally concludes that intervention through telerehabilitation programs is as feasible and efficient as conventional physiotherapy in terms of functionality level and quality of life. In addition, telerehabilitation shows high levels of patients’ satisfaction and adherence, being values equivalent to traditional rehabilitation

Clinical impact of acute kidney injury on short- and long-term outcomes after transcatheter aortic valve implantation with the CoreValve prosthesis

AbstractBackgroundAcute kidney injury (AKI) after cardiac surgery is associated with increased mortality, but few data exist on the occurrence and clinical impact of AKI associated with transcatheter aortic valve implantation (TAVI). The objective of this study was to determine the incidence and prognosis of AKI after percutaneous implantation of the CoreValve® (Medtronic, Minneapolis, MN, USA) prosthesis.MethodsA total of 357 patients with severe aortic stenosis and 9 patients with pure native aortic regurgitation were treated with the CoreValve prosthesis. AKI was defined according to Valve Academic Research Consortium criteria as the absolute increase in serum creatinine ≥0.3mg/dl at 72h post percutaneous procedure.ResultsAKI was identified in 58 patients (15.8%), none of whom required renal replacement therapy. In patients with AKI, the mortality at 30 days was 13.5% compared with 1.6% of patients without AKI, [odds ratio (OR)=12.2 (95% CI 3.53–41.9); p<0.001] and total mortality after a mean of 26.2±17 months was 29.3% vs. 14.9% [OR=2.36 (95% CI 1.23–4.51), p=0.008]. In the multivariate analysis, AKI was an independent predictor of cumulative total mortality [hazard ratio=2.151, (95% CI from 1.169 to 3.957), p=0.014].ConclusionsThe deterioration of renal function in patients undergoing TAVI with the CoreValve prosthesis is a serious and frequent complication. The occurrence of AKI was associated with increased early mortality and was also a predictor of worse outcomes in follow-up

Work shift, lifestyle factors, and subclinical atherosclerosis in spanish male workers: A mediation analysis

(1) Background: Working night shifts has been associated with altered circadian rhythms, lifestyle habits, and cardiometabolic risks. No information on the potential association of working shift and the presence of atherosclerosis is available. The aim of this study was to quantify the association between different work shifts and the presence of subclinical atherosclerosis objectively measured by imaging. (2) Methods: Analyses were conducted on the baseline data of the Aragon Workers Health Study (AWHS) cohort, including information on 2459 middle-aged men. Categories of shift work included central day shift, rotating morning-evening or morning-evening-night shift, and night shift. The presence of atherosclerotic plaques was assessed by 2D ultrasound in the carotid and femoral vascular territories. Multivariable logistic models and mediation analysis were conducted to characterize and quantify the association between study variables. (3) Results: Participants working night or rotating shifts presented an overall worse cardiometabolic risk profile, as well as more detrimental lifestyle habits. Workers in the most intense (morning-evening-night) rotating shift presented higher odds of subclinical atherosclerosis (odds ratio: 1.6; 95% confidence interval: 1.12 to 2.27) compared to workers in the central shift, independently of the presence of lifestyle and metabolic risk factors. A considerable (21%) proportion of this association was found to be mediated by smoking, indicating that altered sleep-wake cycles have a direct relationship with the early presence of atherosclerotic lesions. (4) Conclusions: Work shifts should be factored in during workers health examinations, and when developing effective workplace wellness programs

High-quality intake of carbohydrates is associated with lower prevalence of subclinical atherosclerosis in femoral arteries: The AWHS study

Background and aims: High-quality of the carbohydrates consumed, apart from their total amount, appear to protect from cardiovascular disease (CVD). However, the relationship between the quality of carbohydrates and the early appearance of atherosclerosis has not yet been described. Our objective was to estimate the association between the quality of dietary carbohydrates and subclinical atherosclerosis in femoral and carotid arteries. Methods: Cross-sectional study of femoral and carotid atherosclerosis assessed using ultrasounds of 2074 middle-aged males, 50.9 (SD 3.9) years old, with no previous CVD, and pertaining to the Aragon Workers’ Health Study (AWHS) cohort. Food frequency questionnaires were used to calculate a carbohydrate quality index (CQI) defined as: consumption of dietary fiber, a lower glycemic index, the ratio of whole grains/total grains, and the ratio of solid carbohydrates/total carbohydrates. The presence of plaques across four CQI intervals was studied using adjusted logistic regression models. Results: The CQI showed a direct inverse association with subclinical atherosclerosis in femoral territories. Participants with a higher consumption of high-quality carbohydrates (13–15 points) were less likely to have femoral plaques when compared with participants in the lowest index interval (4–6 points) (OR = 0.59; 95% CI = 0.39, 0.89; p = 0.005). No association was found between the CQI and the presence of subclinical atherosclerosis in carotid territories. A lower consumption of high-quality carbohydrates tended to be associated with a greater atherosclerosis extension, considered as the odds for having more affected territories (p = 0.011). Conclusions: Among middle-aged males, a high-quality intake of carbohydrates is associated with a lower prevalence of femoral artery subclinical atherosclerosis when compared with a lower consumption. Thus, indicating an early relationship between the quality of carbohydrates and the development of CVD. © 2021 The Author(s

Optimal network topologies: Expanders, Cages, Ramanujan graphs, Entangled networks and all that

We report on some recent developments in the search for optimal network topologies. First we review some basic concepts on spectral graph theory, including adjacency and Laplacian matrices, and paying special attention to the topological implications of having large spectral gaps. We also introduce related concepts as ``expanders'', Ramanujan, and Cage graphs. Afterwards, we discuss two different dynamical feautures of networks: synchronizability and flow of random walkers and so that they are optimized if the corresponding Laplacian matrix have a large spectral gap. From this, we show, by developing a numerical optimization algorithm that maximum synchronizability and fast random walk spreading are obtained for a particular type of extremely homogeneous regular networks, with long loops and poor modular structure, that we call entangled networks. These turn out to be related to Ramanujan and Cage graphs. We argue also that these graphs are very good finite-size approximations to Bethe lattices, and provide almost or almost optimal solutions to many other problems as, for instance, searchability in the presence of congestion or performance of neural networks. Finally, we study how these results are modified when studying dynamical processes controlled by a normalized (weighted and directed) dynamics; much more heterogeneous graphs are optimal in this case. Finally, a critical discussion of the limitations and possible extensions of this work is presented.Comment: 17 pages. 11 figures. Small corrections and a new reference. Accepted for pub. in JSTA

Nature of phase transitions in a probabilistic cellular automaton with two absorbing states

We present a probabilistic cellular automaton with two absorbing states, which can be considered a natural extension of the Domany-Kinzel model. Despite its simplicity, it shows a very rich phase diagram, with two second-order and one first-order transition lines that meet at a tricritical point. We study the phase transitions and the critical behavior of the model using mean field approximations, direct numerical simulations and field theory. A closed form for the dynamics of the kinks between the two absorbing phases near the tricritical point is obtained, providing an exact correspondence between the presence of conserved quantities and the symmetry of absorbing states. The second-order critical curves and the kink critical dynamics are found to be in the directed percolation and parity conservation universality classes, respectively. The first order phase transition is put in evidence by examining the hysteresis cycle. We also study the "chaotic" phase, in which two replicas evolving with the same noise diverge, using mean field and numerical techniques. Finally, we show how the shape of the potential of the field-theoretic formulation of the problem can be obtained by direct numerical simulations.Comment: 19 pages with 7 figure

Descripción Anatómica e Histológica del Aparato Digestivo de la Sabaleta (Brycon henni), Antioquia, Colombia

The present study describes the anatomical and histological pattern of the digestive system of the ‘sabaleta’ (Brycon henni). Six adult male and female individuals were fished in Guaracu creek, Antioquia, Colombia, between May and June 2016. The fish weighed 151.2 g and were 22.7 cm in total length. The organs of the digestive system were fixed in 10% buffered formalin and processed with routine histological techniques. The most remarkable structures, due to their specific anatomical pattern and histological complexity, were the gill rakers (4), the pyloric caeca (13 in females and 8 in males), the bulky and lobate hepato-pancreas, and the anterior, middle and posterior intestine with villi and microvilli. The ‘sabaleta’, according to the digestive pattern as to teeth, gill rakers, stomach, and intestinal structure and length, suggests that it is a kind of omnivorous food habit species, but with a carnivorous tendency.El presente estudio hace un análisis del patrón anatómico e histológico del sistema digestivo de la sabaleta (Brycon henni). Fueron capturados seis individuos machos y hembras adultos en la quebrada Guaracú, Antioquia, Colombia, entre mayo y junio de 2016. Los peces pesaron 151.2 g y midieron 22.7 cm de longitud total. Los órganos del aparato digestivo fueron fijados en formol buferado al 10% y procesados con técnicas histológicas de rutina. Las estructuras más resaltantes, debido a su patrón anatómico específico y complejidad histológica fuero las branquiespinas (4), los ciegos pilóricos (13 en hembras y 8 en machos), el hepato-páncreas voluminoso y lobulado, y el intestino anterior, medio y posterior con vellosidades y microvellosidades. La sabaleta, según el patrón digestivo en cuanto a la clase de dientes, branquiespinas, estómago, longitud y estructura intestinal, sugiere que es una especie de hábito alimenticio omnívoro, pero con tendencia carnívora