Cancer growth and metastasis as a metaphor of Go gaming: An Ising model approach

© 2018 Barradas-Bautista et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestric ted use, distribution, and reproduction in any medium, provided the original author and source are credited. This work aims for modeling and simulating the metastasis of cancer, via the analogy between the cancer process and the board game Go. In the game of Go, black stones that play first could correspond to a metaphor of the birth, growth, and metastasis of cancer. Moreover, playing white stones on the second turn could correspond the inhibition of cancer invasion. Mathematical modeling and algorithmic simulation of Go may therefore benefit the efforts to deploy therapies to surpass cancer illness by providing insight into the cellular growth and expansion over a tissue area. We use the Ising Hamiltonian, that models the energy exchange in interacting particles, for modeling the cancer dynamics. Parameters in the energy function refer the biochemical elements that induce cancer birth, growth, and metastasis; as well as the biochemical immune system process of defense

Theoretical analysis of nonlinear amplification effects in massive MIMO systems

To fulfill 5th Generation (5G) communication capacity demands, the use of a large number of antennas has been widely investigated, and the array gain and spatial multiplexing that are offered by massive multiple input multiple output (mMIMO) have been used to improve the capacity. Fully digital architectures are not feasible for a large number of antennas, and hybrid analog/digital systems have emerged as options to retain a high number of antennas without as many radio frequency (RF) chains. However, these systems have, as consequences, non-avoidable nonlinear effects due to power amplifiers functioning in nonlinear regions. The strong nonlinear effects throughout the transmission chain will have a negative impact on the overall system’s performance. Being able to access this impact is very important. For this purpose, we propose analytical and semi-analytical tools that allow for the evaluation of the nonlinear effects of a hybrid analog/digital orthogonal frequency-division multiplexing (OFDM) system. The proposed analysis starts with the characterization of the power amplifier’s (PA) nonlinear response. This response is then used to derive a semi-analytic bit error rate expression. The theoretical tools are validated by using numerical results from two different cases: in the first one, the nonlinear PA response is assumed to follow an analytical model found in the literature and, in the second, the used nonlinear polynomial model mimics the response of a real amplifier. Using these two scenarios, the proposed tools are shown to be accurate making it possible to predict the nonlinearities’ penalties in hybrid analog/digital OFDM systems and/or to assess the optimal operation point for a specific nonlinear amplifier.publishe

Functional and optical properties of Au :TiO2 nanocomposite films : the influence of thermal annealing

A set of nanocomposite thin films consisting of Au nanoclusters dispersed in a TiO2 dielectric matrix was deposited by reactive magnetron sputtering, and subjected to thermal annealing in vacuum, at temperatures ranging from 200 to 800 ◦C. The obtained results show that the structure and the size of Au clusters, together with the matrix crystallinity, changed as a result of the annealing, and were shown to be able to change the optical properties of the films and keeping good mechanical properties, opening thus a wide number of possible applications. The crystallization of the gold nanoclusters induced by the annealing was followed by a systematic change in the overall coating behaviour, namely the appearance of surface plasmon resonance (SPR) behaviour. This effect enables to tailor the thin films reflectivity, absorbance and colour coordinates, contributing to the importance of this thin film system. The different attained optical characteristics (reflectance values ranging from interference to metallic-like behaviours and colour varying for interference rainbow-like to several tones of red-brownish), associated with a reasonable mechanical resistance of the coatings (good adhesion to different substrates and hardness values ranging from 5 to 7.5 GPa), induce the possibility to use this film system in a wide range of decorative applications.Fundac¸ ão para a Ciência e Tecnologia (FCT) - PTDC/CTM/70037/2006

Prednisone and azathioprine in patients with inflammatory cardiomyopathy: systematic review and meta-analysis

Aims: Chronic non-viral myocarditis, also called inflammatory cardiomyopathy, can be treated with immune suppression on tops of optimal medical therapy (OMT) for heart failure, using a combination of prednisolone and azathioprine (IPA). However, there has been inconsistency in the effects of immunosuppression treatment. This meta-analysis is the first to evaluate all available data of the effect of this treatment on left ventricular ejection fraction (LVEF) and the combined clinical endpoint of cardiovascular mortality and/or heart transplantation-free survival. Methods and results: All trials with using IPA vs. OMT in this syndrome were searched using OVID Medline and ClinicalTrials. gov, following the PRISMA guidelines. Missing data were retrieved after contacting the corresponding authors. All data was reviewed and analysed using and standard meta-analysis methods. A random effect model was used to pool the effect sizes. A total of four trials (three randomised controlled trials and one propensity-matched retrospective registry) including 369 patients were identified. IPA on top of OMT did not improve LVEF [mean difference 9.9% (95% confidence interval -1.8, 21.7)] with significant heterogeneity. When we limited our pooled estimate to the published studies only, significant LVEF improvement by IPA was observed [14% (1.4, 26.6)]. No cardiovascular mortality benefit was observed with the intervention [risk ratio 0.34 (0.08, 1.51)]. Conclusions: At the moment, there is insufficient evidence supporting functional and prognostic benefits of IPA added to OMT in virus negative inflammatory positive cardiomyopathy. Further adequate-powered well-designed prospective RCTs should be warranted to explore the potential effects of adding immunosuppressive therapy to OMT