Observation of environment-induced double sudden transitions in geometric quantum correlations

Correlations in quantum systems exhibit a rich phenomenology under the effect of various sources of noise. We investigate theoretically and experimentally the dynamics of quantum correlations and their classical counterparts in two nuclear magnetic resonance setups, as measured by geometric quantifiers based on trace-norm. We consider two-qubit systems prepared in Bell diagonal states, and perform the experiments in decohering environments resulting from Bell diagonal-preserving Markovian local noise. We then report the first observation of environment-induced double sudden transitions in the geometric quantum correlations, a genuinely nonclassical effect not observable in classical correlations. The evolution of classical correlations in our physical implementation reveals in turn the finite-time relaxation to a pointer basis under nondissipative decoherence, which we characterize geometrically in full analogy with predictions based on entropic measures.Comment: 5 pages, 2 figures. v2: Minor corrections. Published versio

Dairy products and inflammation: a review of the clinical evidence

Inflammation is a major biological process regulating the interaction between organisms and the environment, including the diet. Because of the increase in chronic inflammatory diseases, and in light of the immune-regulatory properties of breastfeeding, the ability of dairy products to modulate inflammatory processes in humans is an important but unresolved issue. Here, we report a systematic review of 52 clinical trials investigating inflammatory markers in relation to the consumption of dairy products. An inflammatory score (IS) was defined to quantitatively evaluate this interaction. The IS was significantly positive for the entire data set, indicating an anti-inflammatory activity in humans. When the subjects were stratified according to their health status, the IS was strongly indicative of an anti-inflammatory activity in subjects with metabolic disorders and of a pro-inflammatory activity in subjects allergic to bovine milk. Stratifying the data by product categories associated both low-fat and high-fat products, as well as fermented products, with an anti-inflammatory activity. Remarkably, the literature is characterized by a large gap in knowledge on bioavailability of bioactive nutrients. Future research should thus better combine food and nutritional sciences to adequately follow the fate of these nutrients along the gastrointestinal and metabolic axes.info:eu-repo/semantics/publishedVersio

Ser diplomado do ensino superior: escolhas, percursos e retornos

Textos selecionados a partir de comunicações apresentadas no 3.º Seminário “Ser Diplomado do Ensino Superior: Escolhas, Percursos e Retornos”, realizado pelo ObservatoriUM - Observatório dos Percursos Académicos dos Estudantes da Universidade do Minho (Campus de Gualtar, 9 de junho de 2017).Este trabalho é financiado pelo CIEd - Centro de Investigação em Educação, projetos UID/CED/1661/2013 e UID/CED/1661/2016, Instituto de Educação, Universidade do Minho, através de fundos nacionais da FCT/MCTES-PT.info:eu-repo/semantics/publishedVersio

Dysmetabolism and Sleep Fragmentation in Obstructive Sleep Apnea Patients Run Independently of High Caffeine Consumption

Funding Information: This research was funded by the Portuguese Science and Technology Foundation (FCT) with the grant number CEECIND/04266/2017. Acknowledgments: The authors would like to thank Eunice Silva for technical support. Funding Information: Funding: This research was funded by the Portuguese Science and Technology Foundation (FCT) with the grant number CEECIND/04266/2017.Daytime hypersomnolence, the prime feature of obstructive sleep apnea (OSA), frequently leads to high coffee consumption. Nevertheless, some clinicians ask for patients’ caffeine avoidance. Caffeinated drinks are sometimes associated with more severe OSA. However, these effects are not consensual. Here we investigated the effect of caffeine consumption on sleep architecture and apnea/hypopnea index in OSA. Also, the impact of caffeine on variables related with dysmetabolism, dyslipidemia, and sympathetic nervous system (SNS) dysfunction were investigated. A total of 65 patients diagnosed with OSA and 32 without OSA were included after given written informed consent. Polysomnographic studies were performed. Blood was collected to quantify caffeine and its metabolites in plasma and biochemical parameters. 24 h urine samples were collected for catecholamines measurement. Statistical analyses were performed by SPSS: (1) non-parametric Mann-Whitney test to compare variables between controls and OSA; (2) multivariate logistic regression testing the effect of caffeine on sets of variables in the 2 groups; and (3) Spearmans’ correlation between caffeine levels and comorbidities in patients with OSA. As expected OSA development is associated with dyslipidemia, dysmetabolism, SNS dysfunction, and sleep fragmentation. There was also a significant increase in plasma caffeine levels in the OSA group. However, the higher consumption of caffeine by OSA patients do not alter any of these associations. These results showed that there is no apparent rationale for caffeine avoidance in chronic consumers with OSA.publishersversionpublishe

Nanoliposomes for encapsulation and delivery of the potential antitumoral methyl 6-methoxy-3-(4-methoxyphenyl)-1H-indole-2-carboxylate

A potential antitumoral fluorescent indole derivative, methyl 6-methoxy-3-(4-methoxyphenyl)-1H-indole-2-carboxylate, was evaluated for the in vitro cell growth inhibition on three human tumor cell lines, MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), and NCI-H460 (non-small cell lung cancer), after a continuous exposure of 48 h, exhibiting very low GI50 values for all the cell lines tested (0.25 to 0.33 µM). This compound was encapsulated in different nanosized liposome formulations, containing egg lecithin (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylglycerol (DPPG), DSPC, cholesterol, dihexadecyl phosphate, and DSPE-PEG. Dynamic light scattering measurements showed that nanoliposomes with the encapsulated compound are generally monodisperse and with hydrodynamic diameters lower than 120 nm, good stability and zeta potential values lower than −18 mV. Dialysis experiments allowed to monitor compound diffusion through the lipid membrane, from DPPC/DPPG donor liposomes to NBD-labelled lipid/DPPC/DPPG acceptor liposomes.Thanks are due to the Foundation for Science and Technology (FCT, Portugal) for financial support through the research centers (CFUM and CQ-UM) and project PTDC/QUI/81238/2006 (cofinanced by FEDER/COMPETE, ref. FCOMP-01-0124-FEDER-007467). A.S. Abreu (SFRH/BPD/24548/2005) and L. Vale-Silva (SFRH/BPD/29112/2006) acknowledge FCT for their postdoctoral grants

Development of biocompatible plasmonic thin films composed of noble metal nanoparticles embedded in a dielectric matrix to enhance Raman signals

This work focused on the production of nanocomposite thin films, composed of noble nanoparticles embedded in a dielectric matrix, to be tested as biocompatible plasmonic platforms for detection of molecules using Surface Enhance Raman Spectroscopy (SERS). Three different thin films systems were deposited by reactive DC magnetron sputtering, namely Au-Al2O3, Au-TiO2 and Ag-TiO2. The depositions were followed by a thermal treatment at different temperatures to promote the growth of the nanoparticles. Localized Surface Plasmon Resonance (LSPR) bands appeared already at 300 °C, related to the presence of Au nanoparticles, and at 500 °C in the case of Ag nanoparticles. Furthermore, at 700 °C, the Ag-TiO2 films showed a broadband optical response due to the formation of Ag clusters at the film's surface. The biological experiments showed that the presence of the thin films didn't affect the growth of C. albicans, which is very convenient if one needs to detect low concentrations of this microorganism using SERS platforms. As for the SERS measurements, an enhancement of R6G Raman spectra intensity was clearly perceivable, but only for the TiO2 matrix. Furthermore, the application of a plasma treatment allowed to better expose the nanoparticles, providing a further enhancement of Raman signals.FCT - Fundação para a Ciência e a Tecnologia (PTDC/FIS-NAN/1154/2014

Effect of Iodide-Based Organic Salts and Ionic Liquid Additives in Dye-Sensitized Solar Cell Performance

Funding Information: This work was performed under the project PTDC/QUI-QOR/7450/2020 “Organic Redox Mediators For Energy Conversion” through Fundação para a Ciência e a Tecnologia I. P.-FCT. Additional support includes the Associate Laboratory for Green Chemistry–LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020). FCT/MCTES is also acknowledged for the National NMR Facility (RECI/BBB-BQB/0230/2012 and RECI/BBB-BEP/0124/2012,) and Ph.D. grants 2020.09047.BD (J.S.), PD/BD/135087/2017 (A.L.P.) and PD/BD/145324/2019/ (G.M.). Publisher Copyright: © 2022 by the authors.The use of ionic liquid and organic salts as additives for electrolyte systems in dye-sensitized solar cells have been widely described in recent years. The tunability of their physical-chemical properties according to the cation–anion selection contributes toward their high efficiencies. For this purpose, several iodide-based organic salts including imidazolium, picolinium, guanidinium and alkylammonium cations were tested using acetonitrile/valeronitrile electrolytes and their photovoltaic parameters were compared. A best efficiency of 4.48% (4.15% for the reference) was found for 1-ethyl-2,3-dimethylimidazolium iodide ([C2DMIM]I) containing electrolyte, reaffirming the effectiveness of these additives. 4-tertbutylpyridine was included into the formulation to further improve the performance while determining which iodide salts demonstrate the highest synergy with this additive. [C2DMIM]I once again proved to be the superior additive, achieving an efficiency of 6.48% (6% for the reference). Electrochemical impedance spectroscopy was employed to elucidate the effects of the various additives, demonstrating the relevance of the counter electrode resistance on device performance. Finally, several computational descriptors for the cationic structures were calculated and correlated with the photovoltaic and resistance parameters, showing that properties related to polarity, namely relative positive charge, molecular polarizability and partition coefficient are in good agreement with the counter-electrode resistance.publishersversionpublishe

Aging increases oxidative stress and renal expression of oxidant and antioxidant enzymes that are associated with an increased trend in systolic blood pressure

The aim of this study was to investigate whether the effects of aging on oxidative stress markers and expression of major oxidant and antioxidant enzymes associate with impairment of renal function and increases in blood pressure. To explore this, we determined age-associated changes in lipid peroxidation (urinary malondialdehyde), plasma and urinary hydrogen peroxide (H2O2) levels, as well as renal H2O2 production, and the expression of oxidant and antioxidant enzymes in young (13 weeks) and old (52 weeks) male Wistar Kyoto (WKY) rats. Urinary lipid peroxidation levels and H2O2 production by the renal cortex and medulla of old rats were higher than their young counterparts. This was accompanied by overexpression of NADPH oxidase components Nox4 and p22phox in the renal cortex of old rats. Similarly, expression of superoxide dismutase (SOD) isoforms 2 and 3 and catalase were increased in the renal cortex from old rats. Renal function parameters (creatinine clearance and fractional excretion of sodium), diastolic blood pressure and heart rate were not affected by aging, although slight increases in systolic blood pressure were observed during this 52-week period. It is concluded that overexpression of renal Nox4 and p22phox and the increases in renal H2O2 levels in aged WKY does not associate with renal functional impairment or marked increases in blood pressure. It is hypothesized that lack of oxidative stress-associated effects in aged WKY rats may result from increases in antioxidant defenses that counteract the damaging effects of H2O2

About the sterilization of chitosan hydrogel nanoparticles

In the last years, nanostructured biomaterials have raised a great interest as platforms for delivery of drugs, genes, imaging agents and for tissue engineering applications. In particular, hydrogel nanoparticles (HNP) associate the distinctive features of hydrogels (high water uptake capacity, biocompatibility) with the advantages of being possible to tailor its physicochemical properties at nano-scale to increase solubility, immunocompatibility and cellular uptake. In order to be safe, HNP for biomedical applications, such as injectable or ophthalmic formulations, must be sterile. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns HNP. This work aims to evaluate the effect and effectiveness of different sterilization methods on chitosan (CS) hydrogel nanoparticles. In addition to conventional methods (steam autoclave and gamma irradiation), a recent ozone-based method of sterilization was also tested. A model chitosan-tripolyphosphate (TPP) hydrogel nanoparticles (CS-HNP), with a broad spectrum of possible applications was produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol). Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. It was found that the CS-HNP degrade by autoclaving and that sugars have no protective effect. Concerning gamma irradiation, the formation of agglomerates was observed, compromising the suspension stability. However, the nanoparticles resistance increases considerably in the presence of the sugars. Ozone sterilization did not lead to significant physical adverse effects, however, slight toxicity signs were observed, contrarily to gamma irradiation where no detectable changes on cells were found. Ozonation in the presence of sugars avoided cytotoxicity. Nevertheless, some chemical alterations were observed in the nanoparticles.info:eu-repo/semantics/publishedVersio

Transnational cooperation in enhancing researchers’ wider employability: the TRANSPEER project

The purpose of this paper is to provide an example of best practice towards enhancing employability in the cross-sectoral labour market for doctorate-holders. This was achieved through an Erasmus+ KA2 (Strategic Partnership) skills development project which created a training programme (TRANSPEER) involving a multi-disciplinary cohort of researchers at a range of career stages, drawn from universities in Norway, Portugal, Sweden and the UK.info:eu-repo/semantics/publishedVersio