61 research outputs found

    Exploring the “Middle Earth” of network spectra via a Gaussian matrix function

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    We study a Gaussian matrix function of the adjacency matrix of artificial and real-world networks. We motivate the use of this function on the basis of a dynamical process modeled by the time-dependent Schrodinger equation with a squared Hamiltonian. In particular, we study the Gaussian Estrada index - an index characterizing the importance of eigenvalues close to zero. This index accounts for the information contained in the eigenvalues close to zero in the spectra of networks. Such method is a generalization of the so-called "Folded Spectrum Method" used in quantum molecular sciences. Here we obtain bounds for this index in simple graphs, proving that it reaches its maximum for star graphs followed by complete bipartite graphs. We also obtain formulas for the Estrada Gaussian index of Erdos-Renyi random graphs as well as for the Barabasi-Albert graphs. We also show that in real-world networks this index is related to the existence of important structural patters, such as complete bipartite subgraphs (bicliques). Such bicliques appear naturally in many real-world networks as a consequence of the evolutionary processes giving rise to them. In general, the Gaussian matrix function of the adjacency matrix of networks characterizes important structural information not described in previously used matrix functions of graphs

    Survival of atraumatic restorative treatment (ART) sealants and restorations: a meta-analysis

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    The purpose of this study is to perform a systematic investigation plus meta-analysis into survival of atraumatic restorative treatment (ART) sealants and restorations using high-viscosity glass ionomers and to compare the results with those from the 2005 ART meta-analysis. Until February 2010, four databases were searched. Two hundred four publications were found, and 66 reported on ART restorations or sealant survival. Based on five exclusion criteria, two independent reviewers selected the 29 publications that accounted for the meta-analysis. Confidence intervals (CI) and or standard errors were calculated and the heterogeneity variance of the survival rates was estimated. Location (school/clinic) was an independent variable. The survival rates of single-surface and multiple-surface ART restorations in primary teeth over the first 2 years were 93% (CI, 91–94%) and 62% (CI, 51–73%), respectively; for single-surface ART restorations in permanent teeth over the first 3 and 5 years it was 85% (CI, 77–91%) and 80% (CI, 76–83%), respectively and for multiple-surface ART restorations in permanent teeth over 1 year it was 86% (CI, 59–98%). The mean annual dentine lesion incidence rate, in pits and fissures previously sealed using ART, over the first 3 years was 1%. No location effect and no differences between the 2005 and 2010 survival rates of ART restorations and sealants were observed. The short-term survival rates of single-surface ART restorations in primary and permanent teeth, and the caries-preventive effect of ART sealants were high. Clinical relevance: ART can safely be used in single-surface cavities in both primary and permanent teeth. ART sealants have a high caries preventive effect

    Metal Nanoparticles against Viruses: Possibilities to Fight SARS-CoV-2

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    In view of the current Coronavirus Disease 2019 (COVID-19) pandemic outbreak, the research community is focusing on development of diagnostics, treatment, and vaccines to halt or reverse this scenario. Although there are already various vaccines available, adaptive mutations in the SARS-CoV-2 genome can alter its pathogenic potential and, at the same time, increase the difficulty of developing drugs or immunization by vaccines. Nanotechnology carries a potential to act in all stages in fighting this viral disease, with several possibilities of strategies such as applying nanoparticles directly as antivirals in delivery systems against these viruses or incorporating them in materials, with power of achievement in therapeutics, vaccines and prevention. In this paper, we review and bring insights of recent studies using metal nanocomposites as antivirals against coronavirus and structurally similar viruses

    <b> EFEITO DA ERVA-MATE (<i>ILEX PARAGUARIENSIS</i> A. ST. HIL.) SOBRE O PERFIL METABÓLICO EM RATOS ALIMENTADOS COM DIETAS HIPERLIPÃDICAS</b>

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    <p class="MsoNormal" style="margin: 0cm 0cm 0pt; line-height: normal; text-align: justify; mso-layout-grid-align: none;"> O objetivo do presente estudo foi avaliar o efeito da infusão de erva-mate sobre o perfil metabólico em ratos alimentados com dietas hiperlipídicas. Foram estudados 36 ratos, linhagem <i>Wistar<i>, machos adultos, divididos em seis grupos (n=6): controle Ã¥gua; controle mate; hipercolesterolÃÂȘmico Ã¥gua + banha; hipercolesterolÃÂȘmico mate + banha; hipercolesterolÃÂȘmico Ã¥gua + gordura vegetal hidrogenada e hipercolesterolÃÂȘmico mate + gordura vegetal hidrogenada. Os animais foram acomodados individualmente em gaiolas metabólicas de aço inoxidÃ¥vel, com temperatura ambiente de 22ÂÂșC + 2ÂÂșC e fotoperíodo de 12 horas (claro/escuro). Durante as 5 semanas do estudo, os grupos hipercolesterolÃÂȘmicos receberam 1% de colesterol sintético e 10% de gordura vegetal hidrogenada ou saturada adicionados à dieta controle. Na 3ÂÂȘ semana iniciou-se o tratamento com a infusão de erva mate. Não se observou no presente estudo efeito signifi cativo e abrangente da erva-mate sobre todos os parùmetros avaliados. Entretanto, verifi cou-se tendÃÂȘncia de menor ganho de peso e redução dos parùmetros de glicemia, peso de fígado e transaminases, além de aumento de HDL-colesterol na presença de dieta com gordura saturada nos animais tratados com erva mate. Tais resultados são promissores e sugerem que novos estudos investiguem o possível efeito protetor da <i>Ilex paraguariensis</i> A. St. Hil. sobre o perfil metabólico. </p&gt

    Relative mRNA levels of pro-inflammatory cytokines, interferon-stimulated genes, and pattern-recognition receptors in the right cranial lobe.

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    RNA was normalized to 1Όg and gene expression was assessed by qPCR and normalized to RLP-19 expression in. Values are shown as log2 fold induction of the mean between the seeder pigs (n = 3) of each group at 5dpi. Fold induction of each group was normalized to the non-infected negative control group. Values represent the mean ± SEM. Statistical analysis was performed by two-way ANOVA. *p (TIFF)</p
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