Superhydrophobic asphalt pavements: surface improvement

The most adverse weather condition for road safety happens when there is water, snow, or ice on the road surface because their presence highly decreases friction. Therefore, it is essential to drain or repel them quickly. If the water drops are repelled from the surface or the ice/snow formation is avoided with the application of superhydrophobic coatings, roads become safer. In order to functionalize the asphalt mixtures used in road pavements, nano/micromaterials, such as Polytetrafluoroethylene (PTFE), TiO2, and SiO2, among others have been applied by spraying coating. The mixes are usually characterized by the water contact angle, and the surface roughness is typically assessed by optical and electron analysis. This research work aims to present a brief overview of superhydrophobic asphalt mixtures

Wave function mapping conditions in Open Quantum Dots structures

We discuss the minimal conditions for wave function spectroscopy, in which resonant tunneling is the measurement tool. Two systems are addressed: resonant tunneling diodes, as a toy model, and open quantum dots. The toy model is used to analyze the crucial tunning between the necessary resolution in current-voltage characteristics and the breakdown of the wave functions probing potentials into a level splitting characteristic of double quantum wells. The present results establish a parameter region where the wavefunction spectroscopy by resonant tunneling could be achieved. In the case of open quantum dots, a breakdown of the mapping condition is related to a change into a double quantum dot structure induced by the local probing potential. The analogy between the toy model and open quantum dots show that a precise control over shape and extention of the potential probes is irrelevant for wave function mapping. Moreover, the present system is a realization of a tunable Fano system in the wave function mapping regime.Comment: 6 pages, 6 figure

Transport properties of copper phthalocyanine based organic electronic devices

Ambipolar charge carrier transport in Copper phthalocyanine (CuPc) is studied experimentally in field-effect transistors and metal-insulator-semiconductor diodes at various temperatures. The electronic structure and the transport properties of CuPc attached to leads are calculated using density functional theory and scattering theory at the non-equilibrium Green's function level. We discuss, in particular, the electronic structure of CuPc molecules attached to gold chains in different geometries to mimic the different experimental setups. The combined experimental and theoretical analysis explains the dependence of the mobilityand the transmission coefficient on the charge carrier type (electrons or holes) and on the contact geometry. We demonstrate the correspondence between our experimental results on thick films and our theoretical studies of single molecule contacts. Preliminary results for fluorinated CuPc are discussed.Comment: 18 pages, 16 figures; to be published in Eur. Phys. J. Special Topic

Nanodispersions of beta-carotene: effects on antioxidant enzymes and cytotoxic properties

Beta-carotene is a carotenoid precursor of vitamin A, known for its biological activities. Due to its high hydrophobicity, nanonization processes, i.e. the transformation into nanoparticles, can improve its water affinity, and therefore the activity in aqueous systems. The objective of this study was to produce beta-carotene nanoparticles by the solid dispersion method and to evaluate their effects on the activity of glutathione-S-transferase and acetylcholinesterase enzymes using Drosophila melanogaster (DM) homogenate, the superoxide dismutase- and catalase-like activities under in vitro conditions, and their cytotoxic properties against tumor and non-tumor cells. The formed nanometric beta-carotene particles resulted in stable colloids, readily dispersed in water, able to modulate acetylcholinesterase (AChE) activity, and presenting high potential to control the cholinergic system. Beta-carotene nanoparticles, at concentrations much lower than the pure pristine beta-carotene, presented in vitro mimetic activity to superoxide dismutase and altered glutathione-S-transferase activity in DM tissue. The content of hydrogen peroxide was neither affected by the nanoparticles (in aqueous solution) nor by pristine beta-carotene (in DMSO). In the cytotoxic assays, beta-carotene nanoparticles dispersed in water showed activity against four different tumor cell lines. Overall, beta-carotene nanoparticles presented significant bioactivity in aqueous medium surpassing their high hydrophobicity constraint.The authors thank CNPq, CAPES and Fundação Araucária for the support. The authors are also grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (strategic project UID/AGR/00690/2013) and R. Calhelha contract, and to the project POCI-01-0145- FEDER-006984 – Associate Laboratory LSRE-LCM funded by the FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT. This work was also funded by the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and Project Mobilizador ValorNatural®.info:eu-repo/semantics/publishedVersio

Systematic study on the extraction of antioxidants from pinhão (araucaria angustifolia (bertol.) Kuntze) coat

Food by-products containing bioactive substances have attracted attention due to the possibility of adding values to residues of the food industry. In this work, the extraction of phenolic compounds from pinhão seed coats (Araucaria angustifolia (Bertol.) Kuntze) using a central composite rotatable design was applied to obtain prediction models for the extract volume yield, total phenolic content, total phenolic acids and total flavonoids. Principal component analysis and hierarchical cluster analysis were implemented showing an evident poor effect of the temperature on phenolic compounds extraction, which is in accordance with the prediction model obtained by the experimental design for total phenolic acids. Volume yield presented a high positive correlation with extraction temperature, followed by solvent composition. Scanning electron microscopy showed that higher temperatures and lower ethanol percentages resulted in highly defibrillated pinhão coats that retained more extract after the extraction process, leading to lower volume yield percentages.Authors thank the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the master scholarship and the ‘Centro Multiusuário de Caracterização de Materiais (CMCM) of UTFPR-Campus Curitiba’ for the SEM analysis. Authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros contract. The authors are also grateful to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E. Also to POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCICOMPETE2020 and FCT.info:eu-repo/semantics/publishedVersio

On the Quantum Invariant for the Spherical Seifert Manifold

We study the Witten--Reshetikhin--Turaev SU(2) invariant for the Seifert manifold $S^3/\Gamma$ where $\Gamma$ is a finite subgroup of SU(2). We show that the WRT invariants can be written in terms of the Eichler integral of the modular forms with half-integral weight, and we give an exact asymptotic expansion of the invariants by use of the nearly modular property of the Eichler integral. We further discuss that those modular forms have a direct connection with the polyhedral group by showing that the invariant polynomials of modular forms satisfy the polyhedral equations associated to $\Gamma$.Comment: 36 page

The influence of Castanea sativa Mill. flower extract on hormonally and chemically induced prostate cancer in a rat model

Prostate cancer (PCa) is one of the most common cancers in men, with a huge impact on their health. The use of Castanea sativa Mill. flowers (CFs) in beverages has been reported, through ancestral claims, as having health benefits. In vitro research has evidenced the properties of CFs, such as antitumor and antioxidant activities. This study aimed to evaluate the effects of CF extract in an animal model of PCa. Forty male Wistar Unilever rats were randomly assigned to four groups: control, induced, control + CF, and induced + CF groups. Animals from the induced groups were exposed to a multistep protocol for PCa induction. The CF extract, rich in trigalloyl-HHDP-glucoside and obtained via decoction, was administered to the CF groups in drinking water (3 mg per animal per day) for 49 weeks. Animals were sacrificed at 61 weeks of age. Regarding the effects of CFs on dorsolateral prostate tumorigenesis, no significant differences were observed between the induced and induced + CF groups. However, animals exposed to the CF extract showed fewer inflammation areas on the dorsolateral prostate lobe than those not exposed to CF. Moreover, the CF extract alleviated the hepatic oxidative stress associated with the multistep protocol, resulting in lower levels of lipid peroxidation. These results suggest that CF extract has antioxidant and anti-inflammatory properties. This journal is.This work was supported by European Investment Funds by FEDER/COMPETE/POCI - Operational Competitiveness and Internationalization and National Funds by FCT - Portuguese Foundation for Science and Technology, under the projects UIDB/04033/2020 (CITAB), UIDB/00690/2020 (CIMO), UIDB/50006/2020 (LAQV), UIDB/CVT/00772/2020 (CECAV), and UIDP/00616/2020 (CQ-VR), the project RUNawayPCa (POCI-01-0145- FEDER-016728 and PTDC/DTP-DES/6077/2014), and PhD fellowship SFRH/BD/136747/2018. L. Barros also acknowledges national funding by FCT, P.I., through the institutional scientific employment program-contract for her contract. The Interreg Program received financial support from the Project IBERPHENOL, Project Number 0377_IBERPHENOL_6_E, cofinanced by the European Regional Development Fund (ERDF) through POCTEP 2014-2020.info:eu-repo/semantics/publishedVersio