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Rational synthesis and simple methodology for the purification of large (35-45 nm in lateral size) and flat (1.0-1.5 nm of height) nitrogen-doped graphene oxide quantum dots (GOQDs) are presented. The methodology allows robust metal-free and acid-free preparation of N-GOQDs with a yield of about 100% and includes hydrothermal treatment of graphene oxide with hydrogen peroxide and ammonia. It was demonstrated that macroscopic impurities can be separated from N-GOQD suspension by their coagulation with 0.9% NaCl solution. Redispersible in water and saline solutions, particles of N-GOQDs were characterized using tip-enhanced Raman spectroscopy (TERS), photoluminescent, XPS, and UV-VIS spectroscopies. The size and morphology of N-GOQDs were studied by dynamic light scattering, AFM, SEM, and TEM. The procedure proposed allows nitrogen-doped GOQDs to be obtained, having 60-51% of carbon, 34-45% of oxygen, and up to 7.2% of nitrogen. The N-GOQD particles obtained in two hours of synthesis contain only pyrrolic defects of the graphene core. The fraction of pyridine moieties grows with the time of synthesis, while the fraction of quaternary nitrogen declines. Application of TERS allows demonstration that the N-GOQDs consist of a graphene core with an average crystallite size of 9 nm and an average distance between nearest defects smaller than 3 nm. The cytotoxicity tests reveal high viability of the monkey epithelial kidney cells Vero in the presence of N-GOQDs in a concentration below 60 mg L -1 . The N-GOQDs demonstrate green luminescence with an emission maximum at 505 nm and sedimentation stability in the cell culture medium., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

Purpose: Our study investigates the effectiveness of aural rehabilitation to decrease depressive symptoms in older adults, and the relationship between hearing loss and depression., Methods: A randomized controlled study was conducted at a hearing rehabilitation center with people over 65 years old. Participants were randomly allocated to the intervention group who received hearing aids, or to the control group. Data collection included pure-tone audiometry and a Portuguese version of the Geriatric Depression Scale assessed at two time points: baseline (P0) and after 4-week period (P1)., Results: The results show that the increase of hearing thresholds in pure-tone audiometry is associated with a significant increase in depressive symptoms (p = 0.001). The effect of aural rehabilitation for improving depressive symptoms was significant in intervention group (p = 0.000) and between groups (p = 0.003) in P1., Conclusion: Age-related hearing loss has adverse effects on older adults' mental health, due to reduced hearing inputs that may increase levels of effort to communicate and affect social engagement, which lead to depression. Hearing aid use improves levels of depression and can promote greater quality of life in older adults., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The high contamination by the SARS-Cov-2 virus has led to the search for ways to minimize contagion. Masks are used as part of a strategy of measures to suppress transmission and save lives. However, they are not sufficient to provide an adequate level of protection against COVID-19. Activated charcoal has an efficient antibacterial action, adsorption and low cost. Here, the interaction between two molecules of activated carbon was analyzed, interacting with two structures of the SARS-Cov-2, through docking and molecular dynamics using the platforms Autodock Vina 4.2.6, Gaussian 09 and Amber 16. As a result, the complexes from ozone-functionalized coal to viral structures happen mainly through hydrophobic interactions at the binding site of each receptor. The values of the mean square deviations of the two systems formed by ligands/receptors and showed better stability. The results of Gibbs free energy showed a better interaction between proteins and functionalized charcoal, with △Gtotal values of -48.530 and -38.882 kcal/mol. Thus, the set formed by combinations of proteins with functionalized activated carbon tends to more efficiently adsorb the protein components of the coronavirus to the pores of the activated carbon with ozone during filtration.

Myocardial infarction triggers cellular events that starts with the activation of inflammatory response and fibrogenic pathways involved in cardiac tissue remodeling. Angiotensin-(1-7) (Ang-(1-7)) is an endogenous heptapeptide from the renin-angiotensin system with a cardioprotective role due to its anti-inflammatory and anti-fibrotic activities in cardiac cells. Although the beneficial aspects of Ang-(1-7) in animal models of cardiac ischemia have been reported, the molecular events underlying Ang-(1-7) cardioprotective effect remains elusive. This study investigated the impact of oral treatment with Ang-(1-7) included in hydroxypropyl β-cyclodextrin (HPβCD/Ang-(1-7)) on the cardiac proteome dysregulation due to experimental myocardial infarction. Wistar male rats were submitted to experimental myocardial infarction and treated daily with HPβCD/Ang-(1-7) during 7 days or 60 days by gavage. Our results showed that HPβCD/Ang-(1-7) treatment ameliorates the post-infarction condition due to the modulation of proteins that initially favor the resolution of inflammation and mitochondrial dysfunction. Moreover, this study reported for the first time that Ang-(1-7) treatment after experimental myocardial infarction leads to the downregulation of the C-X-C chemokine receptor type 4 (CXCR4). SIGNIFICANCE: Myocardial infarction triggers a sequence of cellular and molecular events that starts with an intense inflammatory response that is resolved in the proliferative phase. Prolonged inflammatory phase can lead to adverse cardiac repair and heart failure. In this context, we proposed a post-MI treatment using Ang-(1-7) included in HPβCD and administrated orally. We observed that HPβCD/Ang-(1-7) treatment led to CXCR4 downregulation, highlighting this C-X-C chemokine receptor as a potential therapeutic target for ischemic heart diseases., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Reduced-order modeling using the Volterra series approach has been successfully applied in the past decades to weakly nonlinear aerodynamic and aeroelastic systems. However, aspects regarding the identification of the kernels associated with the convolution integrals of Volterra series can profoundly affect the quality of the resulting reduced-order model (ROM). An alternative method for their identification based on artificial neural networks is evaluated in this work. This relation between the Volterra kernels and the internal parameters of a time-delay neural network is explored for the application in the reduced-order modeling of nonlinear unsteady aerodynamic loads. An impulse-type Volterra-based ROM is also under consideration for comparison. All aerodynamic data used for the construction of the reduced-order models are obtained from computational fluid dynamics (CFD) simulations of the NACA 0012 airfoil using the Euler equations. Prescribed inputs in pitch and in plunge degrees of freedom at different free-stream Mach numbers are used to evaluate the range of applicability of the obtained models. For weakly nonlinear test cases, the modeling performance of the neural network Volterra ROM was comparable to the impulse-type ROM. Additional accuracy and adequate modeling of stronger nonlinearities, however, could only be attained with the inclusion of the neural network kernels of higher-order in the Volterra ROM. A generic expression is derived for the kernel function of p th -order from the internal parameters of a time-delay neural network.

This work presents the synthesis and characterization of extrinsically magnetic poly(butylene succinate) (PBS). PBS is obtained from succinic acid (SA), which can be efficiently produced from renewable biomass by fermentation. Thus, the use of SA helps to remove CO 2 from the atmosphere, constituting a good way to accumulate carbon credits. The magnetic PBS here presented was prepared by fusion using different amounts of maghemite. Obtained materials were characterized using Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), X-ray diffraction (XRD), Small angle X-ray scattering and magnetic force tests. Besides, the oil removal capability (OR) of the samples was also studied. All the magnetic composites were able to remove petroleum from the water. Among them, the one filled with the highest amount of magnetic particles was able to remove 11 g of oil per gram of composite. Also, XRD and SAXS results showed that PBS is a long size oriented material, which allows it to work as a thermoset, avoiding its dissolution in organic contaminant medium. As PBS can also be considered as a platform, these are promising results for the oil spill cleanup applications., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Cell senescence is an important tumour suppressor mechanism and driver of ageing. Both functions are dependent on the development of the senescent phenotype, which involves an overproduction of pro-inflammatory and pro-oxidant signals. However, the exact mechanisms regulating these phenotypes remain poorly understood. Here, we show the critical role of mitochondria in cellular senescence. In multiple models of senescence, absence of mitochondria reduced a spectrum of senescence effectors and phenotypes while preserving ATP production via enhanced glycolysis. Global transcriptomic analysis by RNA sequencing revealed that a vast number of senescent-associated changes are dependent on mitochondria, particularly the pro-inflammatory phenotype. Mechanistically, we show that the ATM, Akt and mTORC1 phosphorylation cascade integrates signals from the DNA damage response (DDR) towards PGC-1β-dependent mitochondrial biogenesis, contributing to aROS-mediated activation of the DDR and cell cycle arrest. Finally, we demonstrate that the reduction in mitochondrial content in vivo, by either mTORC1 inhibition or PGC-1β deletion, prevents senescence in the ageing mouse liver. Our results suggest that mitochondria are a candidate target for interventions to reduce the deleterious impact of senescence in ageing tissues., (© 2016 The Authors. Published under the terms of the CC BY 4.0 license.)