477 research outputs found

    Serum atherogenic lipid markers in subjects from three islands of The Azores Archipelago (Portugal): a comparison study

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    78th Congress of the European- Atherosclerosis -Society (AES): Abstract MS237.Copyright © 2010 Elsevier Ltd. All rights reserved.São Miguel (SM), Graciosa (GR) and São Jorge (SJ) are three islands of the Azores’ Archipelago, where the death rate from coronary artery disease is abouttwice than in mainland Portugal. The aim of this study was to evaluate and compare serum atherogenic lipid markers as reflected by lipid profile, as well as by apoB/apoA-1 ratio in apparently healthy subjects from those islands. The study group was formed by 321 subjects with no chronic diseases, aged 20 to 60 years, born living in the respective island (156 from SM, 92 from GR and 73 from SJ). In all cases, about 64% of subjects were hyperlipidemic, mainly hypercholesterolemic. LDL-C and HDL-C concentrations were respectively, lower and higher in SM than in SJ or GR. ApoB concentration was 40% and 17% higher in SJ than in SM and GR, respectively, while apoA-1 reached the maximum in SM (178±38 mg/dL). Regarding apoB/apoA-1 ratio, taken as a better atherogenic marker then conventional lipid profile, subjects from GR exhibited the highest mean value (0.85±0.4), followed by those from SJ (0.75±0.3) and SM (0.58±0.2). Particularly in men from GR and SJ, ratios were 1.0 and 0.9, respectively, which corresponds to a high risk of developing a cardiovascular incident

    Lattice location and perturbed angular correlation studies of implanted Ag in SrTiO3_{3}

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    Lattice site location and local environment characterization of implanted 111 ⁣^{111}\!Ag in SrTiO3_{3} by means of the emission channeling (EC) and γ\gamma-γ\gamma-perturbed angular correlation (PAC) techniques are reported. The angular distribution of \beta\!^{-}-particles emitted from the 111 ⁣^{111}\!Ag decay was monitored with a position-sensitive detector as a function of annealing temperature up to 900 ºC. In the as-implanted state Ag occupies several lattice sites in SrTiO3_{3}. Upon annealing, near-Sr and near-Ti occupancies increased to 58% and 28%, while an octahedral interstitial fraction vanished. Ag on near-Sr and near-Ti sites are still displaced by \sim0.2--0.5 Å from ideal cubic positions. Subsequent PAC measurements confirmed that ~20% of 111 ⁣^{111}\!Ag atoms are in specific sites of non-cubic environment, characterized by a unique electrical-field-gradient (EFG), while ~80% were subject to a wide EFG distribution

    System-level assessment of a C-RAN based on generalized space–frequency index modulation for 5G new radio and beyond

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    Index modulation (IM) has been attracting considerable research efforts in recent years as it is considered a promising technology that can enhance spectral and energy efficiency and help cope with the rising demand of mobile traffic in future wireless networks. In this paper, we propose a cloud radio access network (C-RAN) suitable for fifth-generation (5G) and beyond systems, where the base stations (BSs) and access points (APs) transmit multidimensional IM symbols, which we refer to as precoding-aided transmitter-side generalized space–frequency IM (PT-GSFIM). The adopted PT-GSFIM approach is an alternative multiuser multiple-input multiple-output (MU-MIMO) scheme that avoids multiuser interference (MUI) while exploiting the inherent diversity in frequency-selective channels. To validate the potential gains of the proposed PT-GSFIM-based C-RAN, a thorough system-level assessment is presented for three different three-dimensional scenarios taken from standardized 5G New Radio (5G NR), using two different numerologies and frequency ranges. Throughput performance results indicate that the 28 GHz band in spite of its higher bandwidth and higher achieved throughput presents lower spectral efficiency (SE). The 3.5 GHz band having lower bandwidth and lower achieved throughput attains higher SE. Overall, the results indicate that a C-RAN based on the proposed PT-GSFIM scheme clearly outperforms both generalized spatial modulation (GSM) and conventional MU-MIMO, exploiting its additional inherent frequency diversity.info:eu-repo/semantics/publishedVersio

    Subcritical carbon dioxide foaming of polycaprolactone for bone tissue regeneration

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    Accepted manuscriptThe preparation of three-dimensional polycaprolactone scaffolds using dense CO2 as foaming agent, without supercritical conditions, was evaluated in this study towards future applications in bone repair. Herein, 3D foams were obtained at 5.0 MPa and 45 °C. To induce bioactivity, β-tricalcium phosphate (β-TCP, 10 wt%) and dexamethasone (5 and 10 wt%) were dispersed in the scaffolds. Foams revealed a pore size range of 164–882 μm, 73–99% porosity and 79–99% interconnectivity, assessed by micro-computed tomography, and a Young modulus of 1.76–2.92 MPa. Dexamethasone did not impair morphology of the matrices in comparison with PCL+β-TCP, which presented a water uptake of nearly 100% after 14 days. A sustained release of dexamethasone was achieved over 35 days in physiologic solution. This study reports the feasibility of using dense CO2 to produce in one-step a porous matrix loaded with active agents opening new possibilities towards injectable systems for in situ foamingEuropean Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number REGPOT-CT2012-316331-POLARIS. It was also funded by the project “Novel smart and biomimetic materials for innovative regenerative medicine approaches” (RL1-ABMR-NORTE-01-0124-FEDER-000016) co-financed by North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF) and the project NORTE‐01‐0145‐FEDER‐000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement. The authors would like to acknowledge the funding of the project Associate Laboratory ICVS/3B’s, under grant agreement number POCI-01-0145-FEDER-007038 supported by FEDER, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT)info:eu-repo/semantics/publishedVersio

    Lattice location and thermal stability of implanted Fe in ZnO

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    The emission channeling technique was applied to evaluate the lattice location of implanted 59^{59}Fe in single-crystalline ZnO. The angular distribution of β\beta^{-}- particles emitted by 59^{59}Fe was monitored with a position-sensitive electron detector, following 60-keV low dose (2.0×10132.0 \times 10^{13} cm2^{-2}) room-temperature implantation of the precursor isotope 59^{59}Mn. The emission patterns around the [0001], [1102], [1101] and [2113] directions revealed that following annealing at 800°C 95(8)% of the Fe atoms occupy ideal substitutional Zn sites with root mean square displacements of 0.06-0.09 Å

    Plasma aminothiol status in the population of the Island of São Jorge (The Azores Archipelago, Portugal)

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    78th Congress of the European- Atherosclerosis -Society (AES): Abstract MS269.Copyright © 2010 Elsevier Ltd. All rights reserved.Hcy, Cys, Cys-Gly and GSH are low molecular weight thiols that play important roles in the metabolism and homeostasis of the organism. An altered plasma aminothiols status can cause oxidative stress, thus contributing to atherogenesis. The aim of this study was to evaluate the plasma levels of total Hcy, Cys, Cys-Gly and GSH, as well as GGT activity in apparently healthy subjects from the Island of S˜ao Jorge, taking into consideration gender and lipid profile. The study group was formed by 73 subjects with no chronic diseases, aged 20 to 60 years, born living in the island of S˜ao Jorge. The evaluation of the four aminothiols was carried out by HPLC with an isocratic reversephase column using a fluorescence detector. Mean values of GSH (1.8±0.6mM) and Cys (240±35mM) content were under reference values, but Cys-Gly was above. Plasma total Hcy, Cys and Cys-Gly levels, as well as GGT activity were significantly higher in men than in women (respectively, 30%, 7%, 17% and 65%). About 63% of subjects were hyperlipidemic, mainly hypercholesterolemic. Cys concentration was increased by 9% in hyperlipidemics vs. normolipidemics. In subjects with altered thiol status men, but not women, revealed a moderate hyperhomocysteinemia. Also Cys-Gly concentrations were significantly higher in men than in women. In spite of being apparently healthy, all subjects (namely men) have depleted antioxidant defenses, indicating high oxidative stress. Alterations in plasma GSH, Cys-Gly and Cys concentrations, taken together, and independently of dyslipidemia, could be considered as early markers of atherosclerosis

    Relationship Between Optimal Gain and Coherence Zone in Flight Simulation

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    In motion simulation the inertial information generated by the motion platform is most of the times different from the visual information in the simulator displays. This occurs due to the physical limits of the motion platform. However, for small motions that are within the physical limits of the motion platform, one-to-one motion, i.e. visual information equal to inertial information, is possible. It has been shown in previous studies that one-to-one motion is often judged as too strong, causing researchers to lower the inertial amplitude. When trying to measure the optimal inertial gain for a visual amplitude, we found a zone of optimal gains instead of a single value. Such result seems related with the coherence zones that have been measured in flight simulation studies. However, the optimal gain results were never directly related with the coherence zones. In this study we investigated whether the optimal gain measurements are the same as the coherence zone measurements. We also try to infer if the results obtained from the two measurements can be used to differentiate between simulators with different configurations. An experiment was conducted at the NASA Langley Research Center which used both the Cockpit Motion Facility and the Visual Motion Simulator. The results show that the inertial gains obtained with the optimal gain are different than the ones obtained with the coherence zone measurements. The optimal gain is within the coherence zone.The point of mean optimal gain was lower and further away from the one-to-one line than the point of mean coherence. The zone width obtained for the coherence zone measurements was dependent on the visual amplitude and frequency. For the optimal gain, the zone width remained constant when the visual amplitude and frequency were varied. We found no effect of the simulator configuration in both the coherence zone and optimal gain measurements

    Influence of O and C co-implantation on the lattice site of Er in GaN

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    The lattice location of low-dose implanted Er in GaN, GaN:O, and GaN:C was investigated using the emission channeling technique. The conversion electrons emitted by the probe isotope 167m^{167m}Er give direct evidence that the majority (~90%) of Er atoms are located on substitutional Ga sites for all samples. Annealing up to 900 °C does not change these fractions, although it reduces the Er root-mean-square (rms) displacements. The only visible effect of oxygen or carbon doping is a small increase in the rms displacements with respect to the undoped sample

    Intron retention in the 5'UTR of the novel ZIF2 transporter enhances translation to promote zinc tolerance in arabidopsis

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    Root vacuolar sequestration is one of the best-conserved plant strategies to cope with heavy metal toxicity. Here we report that zinc (Zn) tolerance in Arabidopsis requires the action of a novel Major Facilitator Superfamily (MFS) transporter. We show that ZIF2 (Zinc-Induced Facilitator 2) localises primarily at the tonoplast of root cortical cells and is a functional transporter able to mediate Zn efflux when heterologously expressed in yeast. By affecting plant tissue partitioning of the metal ion, loss of ZIF2 function exacerbates plant sensitivity to excess Zn, while its overexpression enhances Zn tolerance. The ZIF2 gene is Zn-induced and an intron retention event in its 5'UTR generates two splice variants (ZIF2.1 and ZIF2.2) encoding the same protein. Importantly, high Zn favours production of the longer ZIF2.2 transcript, which compared to ZIF2.1 confers greater Zn tolerance to transgenic plants by promoting higher root Zn immobilization. We show that the retained intron in the ZIF2 5'UTR enhances translation in a Zn-responsive manner, markedly promoting ZIF2 protein expression under excess Zn. Moreover, Zn regulation of translation driven by the ZIF2.2 5'UTR depends largely on a predicted stable stem loop immediately upstream of the start codon that is lost in the ZIF2.1 5'UTR. Collectively, our findings indicate that alternative splicing controls the levels of a Zn-responsive mRNA variant of the ZIF2 transporter to enhance plant tolerance to the metal ion.FCT PostDoctoral Fellowships: SFRH/BPD/44640/2008, SFRH/BPD/81221/2011

    P9 - Antimicrobial properties and bioactivity potential of smart nanoparticles for dental applications

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    Tooth decay is one of the greatest causes of tooth loss in the world. This not only afects the patient’s quality of life but also carries an economic burden associated with the need for multiple reinterventions. Endodontic treatment aims to preserve teeth by cleaning, disinfecting and flling/sealing the root canal. Despite the high success rate of endodontic treatment, failures do occur in a large number of cases. Several new biomaterials for dentistry have been developed, however their bioactivity is often misunderstood. Our work focuses on the biological characterization of novel bioactive glass nanoparticles, including the evaluation of their antimicrobial and biocompatibility properties. Candida albicans (ATCC 11225) and Enterococcus faecalis (ATCC 29212) were included to evaluate the antimicrobial potential by the drop plate method [1]. The cytotoxicity was tested using the MC3T3-E1 cell line, through the resazurin reduction assay. The novel bioactive glass nanoparticles demonstrated antimicrobial activity against C. albicans and E. faecalis, being able to inhibit their growth but also, in some incubation times, decreased the survival of these microorganisms. After 24 h of incubation of MC3T3-E1 osteoblast cells with bioactive glass nanoparticles conditioned medium, around 48% cell viability was achieved. These novel bioactive glass nanoparticles have shown promising properties which may fnd applications on diferent areas of clinical dentistry.info:eu-repo/semantics/publishedVersio
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