Random local strain effects in homovalent-substituted relaxor ferroelectrics: a first-principles study of BaTi0.74Zr0.26O3

We present first-principles supercell calculations on BaTi0.74Zr0.26O3, a prototype material for relaxors with a homovalent substitution. From a statistical analysis of relaxed structures, we give evidence for four types of Ti-atom polar displacements: along the , , or directions of the cubic unit cell, or almost cancelled. The type of a Ti displacement is entirely determined by the Ti/Zr distribution in the adjacent unit cells. The underlying mechanism involves local strain effects that ensue from the difference in size between the Ti4+ and Zr4+ cations. These results shed light on the structural mechanisms that lead to disordered Ti displacements in BaTi(1-x)Zr(x)O3 relaxors, and probably in other BaTiO3-based relaxors with homovalent substitution.Comment: 5 pages, 4 figure

Giant Electroresistance in Ferroelectric Tunnel Junctions

The interplay between the electron transport in metal/ferroelectric/metal junctions with ultrathin ferroelectric barriers and the polarization state of a barrier is investigated. Using a model which takes into account screening of polarization charges in metallic electrodes and direct quantum tunneling across a ferroelectric barrier we calculate the change in the tunneling conductance associated with the polarization switching. We find the conductance change of a few orders of magnitude for metallic electrodes with significantly different screening lengths. This giant electroresistance effect is the consequence of a different potential profile seen by transport electrons for the two opposite polarization orientations.Comment: 4 page

A combined theoretical and experimental study of the low temperature properties of BaZrO3

Low temperature properties of BaZrO3 are revealed by combining experimental techniques (X-ray diffraction, neutron scattering and dielectric measurements) with theoretical first-principles-based methods (total energy and linear response calculations within density functional theory, and effective Hamiltonian approaches incorporating/neglecting zero-point phonon vibrations). Unlike most of the perovskite systems, BaZrO3 does not undergo any (long-range-order) structural phase transition and thus remains cubic and paraelectric down to 2 K, even when neglecting zero-point phonon vibrations. On the other hand, these latter pure quantum effects lead to a negligible thermal dependency of the cubic lattice parameter below ~ 40 K. They also affect the dielectricity of BaZrO3 by inducing an overall saturation of the real part of the dielectric response, for temperatures below ~ 40 K. Two fine structures in the real part, as well as in the imaginary part, of dielectric response are further observed around 50-65 K and 15 K, respectively. Microscopic origins (e.g., unavoidable defects and oxygen octahedra rotation occurring at a local scale) of such anomalies are suggested. Finally, possible reasons for the facts that some of these dielectric anomalies have not been previously reported in the better studied KTaO3 and SrTiO3 incipient ferroelectrics are also discussed.Comment: 8 pages, 5 figures, submitted to Physical Review

A CRIAÇÃO DO CONSELHO NACIONAL DE JUSTIÇA E SUA FUNÇÃO FRENTE À ADMINISTRAÇÃO DA JUSTIÇA BRASILEIRA NO ESTADO DEMOCRÁTICO DE DIREITO

TCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Jurídicas. Direito.O Estado democrático de direito consolidou-se no século XVIII e, em nosso país, foi elevado ao status de principio fundamental na Constituição Federal. Esta prevê, no artigo 2º, os poderes da República, e o princípio da separação de poderes entre eles. Assim, é previsto no ordenamento constitucional vigente os controles sobre esses três poderes. No entanto, nota-se que há uma certa deficiência de um controle sobre o Judiciário. Muito embora a redemocratização do país tenha ocorrido com a promulgação da Constituição Federal em 1988, a justiça brasileira vinha enfrentando um descrédito. Assim, começou um movimento um movimento de reforma e reestruturação do Judiciário brasileiro, que culminou na emenda constitucional nº 45/2004. Nesta emenda, foi prevista a criação do Conselho Nacional de Justiça. Ele é tratado como órgão administrativo do poder judiciário funcionando, portanto, como um instrumento de controle externo deontológico e adiministrativo. Não há, por parte do referido conselho, interferência de outros Poderes ou entidades no controle o Judiciário, ou qualquer atividade externa que vá de encontro a garantia de autogoverno, bem como autonomias administrativa, financeira e orçamentária. O CNJ busca colaborar com a prestação jurisdicional de nosso país, não exercendo, portanto, função jurisdicional, funcionando como órgão meramente administrativo do poder judiciário. Sua competência se restringe a auxiliar na administração não podendo entrar na análise de atos jurisdicionais, tampouco rever conteúdo de decisões judiciais, cabendo obviamente essas questões ao meios processuais previstos nos códigos de processos vigentes.The democratic rule of law was consolidated in the eighteenth century and in our country, was elevated to the status of a fundamental principle in the Constitution. This provides, in Article 2, the branches of government, and the principle of separation of powers between them. Thus, it is foreseen in the current constitutional order controls on these three powers. However, we note that there is a deficiency of a certain control over the judiciary. Although the democratization of the country occurred with the promulgation of the Constitution in 1988, the Brazilian justice system was facing a discredit. Thus began a movement a movement of reform and restructuring of the Brazilian judiciary, culminating in the Constitutional Amendment No. 45/2004. In this amendment, the creation of the National Council of Justice was expected. It is treated as an administrative agency of the judicial branch, thus functioning as an instrument of external control and ethics administrative. There, on the part of the board, interference from other branches or entities in control the judiciary, or any outdoor activity that meets the guarantee of self-government and administrative autonomy, financial and budget. The CNJ search collaborate with the judicial assistance of our country, therefore not exercising judicial function, functioning as purely administrative organ of the judiciary. Its jurisdiction is limited to assisting in the administration could not enter the analysis of judicial acts, nor review the content of judgments, obviously fitting these issues to the remedies provided for in the code of existing processes

Interaction of ZnO Nanostructures with Proteins: In Vitro Fibrillation/Antifibrillation Studies and in Silico Molecular Docking Simulations

Protein amyloidosis is related to many neurological disorders. Nanoparticles (NPs) due to their small size can regulate both the polypeptide monomers/oligomers assembly into amyloid fibrils/plaques and the disintegration of the existent plaques. Herein, we have synthesized ZnO nanoflowers and polyol-coated ZnO NPs of relatively small size (40 nm) with cylindrical shape, through solvothermal and microwave-assisted routes, respectively. The effect of the different morphology of nanostructures on the fibrillation/antifibrillation process was monitored in bovine serum albumin (BSA) and human insulin (HI) by fluorescence Thioflavin T (ThT) measurements. Although both nanomaterials affected the amyloid formation mechanism as well as their disaggregation, ZnO nanoflowers with their sharp edges exhibited the greatest amyloid degradation rate in both model proteins (73% and 35%, respectively) and inhibited the most the insulin fibril growth, while restrained also the fibrillation process in the case of albumin solution. In silico molecular docking simulations on the crystal structure of BSA and HI were performed to analyze further the observed in vitro activity of ZnO nanostructures. The binding energy of ZnO NPs was found lower for BSA (−5.44), highlighting their ability to act as catalysts in the fibrillation process of albumin monomers

Microalgae-derived pigments: a 10-year bibliometric review and industry and market trend analysis

Microalgae productive chains are gaining importance as sustainable alternatives to obtain natural pigments. This work presents a review on the most promising pigments and microalgal sources by gathering trends from a 10 year bibliometric survey, a patents search, and an industrial and market analysis built from available market reports, projects and companies’ webpages. The performed analysis pointed out chlorophylls, phycocyanin, astaxanthin, and β-carotene as the most relevant pigments, and Chlorella vulgaris, Spirulina platensis, Haematococcus pluvialis, and Dunaliella salina, respectively, as the most studied sources. Haematococcus is referred in the highest number of patents, corroborating a high technological interest in this microalga. The biorefinery concept, investment in projects and companies related to microalgae cultivation and/or pigment extraction is increasingly growing, particularly, for phycocyanin from Spirulina platensis. These pieces of evidence are a step forward to consolidate the microalgal pigments market, which is expected to grow in the coming years, increasing the prospects of replacing synthetic pigments by natural counterparts.CIMO (UIDB/00690/2020) and LA LSRE-LCM (UIDB/50020/2020) base funding by national funds through FCT/MCTES (PIDDAC). AIProcMat@N2020 Ref. NORTE-01-0145-FEDER-000006, supported by NORTE 2020 under the Portugal 2020 partnership agreement, through ERDF fund. National funding by FCT through the individual research grant SFRH/BD/148281/2019 (Samara C. Silva).info:eu-repo/semantics/publishedVersio

Characterization and Weathering of the Building Materials of Sanctuaries in the Archaeological Site of Dion, Greece

The sanctuaries of Demeter and Asklepios are part of the Dion archaeological site that sits among the eastern foothills of Mount Olympus. The main building materials are limestones and conglomerates. Sandstones, marbles, and ceramic plinths were also used. The materials consist mainly of calcite and/or dolomite, whereas the deteriorated surfaces contain also secondary and recrystallized calcite and dolomite, gypsum, various inorganic compounds, fluoroapatite, microorganisms and other organic compounds. Cracks and holes were observed in various parts of the stones. The influence of specific weathering agents and factors to the behavior of the materials was examined. The particular environmental conditions in Dion combine increased moisture and rain fall, insolation and great temperature differences, abundance of intensive surface and underground water bodies in the surrounding area, an area full of plants and trees, therefore, they can cause extensive chemical, biological and mechanical decay of the monuments. The following physical characteristics of the building materials have been studied: bulk density, open porosity, pore size distribution, water absorption and desorption, capillary absorption and desorption. The chemical composition of bulk precipitation, surface and underground water was investigated. The salts presence and crystallization was examined. The influence of the water presence to the behavior of the materials was examined by in situ IR thermometer measurements. Temperature values increased from the lower to the upper parts of the building stones and they significantly depend on the orientation of the walls. The results indicate the existence of water in the bulk of the materials due to capillary penetration. The existence of water in the bulk of the materials due to capillary penetration, the cycles of wet-dry conditions, correlated with the intensive surface and underground water presence in the whole surrounding area, lead to partial dissolution-recrystallization of the carbonate material and loss of the structural cohesion and the surface stability

Fluoroscopy-guided procedures in cardiology: is patient exposure being reduced over time?

The number of fluoroscopy-guided procedures in cardiology is increasing over time and it is appropriate to wonder whether technological progress or change of techniques is influencing patient exposure. The aim of this study is to examine whether patient dose has been decreasing over the years. Patient dose data of more than 7700 procedures were collected from two cardiology centres. A steady increase in the patient dose over the years was observed in both the centres for the two cardiological procedures included in this study. Significant increase in dose was also observed after the installation of a flat-panel detector. The increasing use of radial access may lead to an increase in the patient exposure. The monitoring of dose data over time showed a considerable increase in the patient exposure over time. Actions have to be taken towards dose reduction in both the centre

Poling effect on distribution of quenched random fields in a uniaxial relaxor ferroelectric

The frequency dependence of the dielectric permitivity's maximum has been studied for poled and unpoled doped relaxor strontium barium niobate $Sr_{0.61}Ba_{0.39}Nb_{2}O_{6}:Cr^{3+}$ (SBN-61:Cr). In both cases the maximum found is broad and the frequency dispersion is strong. The present view of random fields compensation in the unpoled sample is not suitable for explaining this experimental result. We propose a new mechanism where the dispersion of quenched random electric fields, affecting the nanodomains, is minimized after poling. We test our proposal by numerical simulations on a random field Ising model. Results obtained are in agreement with the polarization's measurements presented by Granzow et al. [Phys. Rev. Lett {\bf 92}, 065701 (2004)].Comment: 7 pages, 4 figure

Nurse-led interventions among older adults affected by cancer: an integrative review.

Aging can introduce significant changes in health, cognition, function, social, and emotional status among older adults affected by cancer. Little is known about how existing nurse-led interventions address the needs of older adults. The objective was to identify existing nurse-led interventions among older adults to optimize recovery and survivorship needs. A integrative systematic review was reported conducted according to the PRISMA 2020 Guidelines. Electronic databases (APA PsycINFO, CINAHL, MEDLINE, Scopus, and Google Scholar databases) were searched using key search terms. Articles were assessed for inclusion according to a pre-determined eligibility criterion. Data extraction and quality appraisal were conducted. Findings were integrated in a narrative synthesis. 21 studies were included and a total of 4,253 participants represented. There were a range of study designs: quantitative (n=10), randomised controlled trials (n=6), mixed methods studies (n=3), qualitative (n=1) and a non-randomised controlled study (n=1). Most participants had prostate cancer with some representation in colorectal, lung, head and neck, renal, oesophageal, and mixed cancer patient populations. This review shows a lack of evidence on the inclusion of geriatric assessments for older people with cancer within existing nurse-led interventions. Further research is needed to test nurse-led interventions with the inclusion of geriatric assessments, and their contribution in the multidisciplinary team across the cancer care continuum for various cancer patient populations