370 research outputs found

    Dielectric and conductivity relaxation in mixtures of glycerol with LiCl

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    We report a thorough dielectric characterization of the alpha relaxation of glass forming glycerol with varying additions of LiCl. Nine salt concentrations from 0.1 - 20 mol% are investigated in a frequency range of 20 Hz - 3 GHz and analyzed in the dielectric loss and modulus representation. Information on the dc conductivity, the dielectric relaxation time (from the loss) and the conductivity relaxation time (from the modulus) is provided. Overall, with increasing ion concentration, a transition from reorientationally to translationally dominated behavior is observed and the translational ion dynamics and the dipolar reorientational dynamics become successively coupled. This gives rise to the prospect that by adding ions to dipolar glass formers, dielectric spectroscopy may directly couple to the translational degrees of freedom determining the glass transition, even in frequency regimes where usually strong decoupling is observed.Comment: 8 pages, 7 figure

    Agronomic practices change the patterns of soil glomalin in olive rainfed orchards

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    Glomalin, a thermostable hydrophobic glycoprotein produced by arbuscular mycorrhizal fungi, plays an important role in the stability of soil aggregates and in the sequestration of C, N and heavy metals, being their concentrations dependent from agronomic practices such as tillage and application of pesticides and fertilizers. Despite the recognized importance of glomalin in soil quality, studies on olive groves are scarce. The study conducted on summer 2017 in three different rain fed orchards (cv. Cobran~osa) of Northeast Portugal revealed that both total glomalin, measured as Bradford-reactive soil protein (T-BRSP}, and the easily extractable Bradford-reactive soil protein (EE-BRSP) concentrations were lower under mechanical cultivation than on a permanent sward grazed with a flock of sheep or than on an annual legume cover crop. Moreover, higher TBRSP and EE-BRSP levels were found on orchards without phosphorus and boron supply, and also on the top soil layer (0.1 0 cm) and on tree row, mainly in younger orchards. Interestingly, one soil presented a twofold superior EE-BRSP: T- BRSP ratio than the other two soils, representing an increase of labile g lomalin, probably re lated with greater applications of copper formulations to control olive fungal diseases. This study demonstrated that less disruptive agronomic practices influences positivety the levels of glomalin, an appropriate indicator of healthy soil conditions, which in turn may favour carbon sequestration.This work was funded by the INTERACT project - •Integrative Research in Environment, Agro-Chains and Technology': no. NORTE-01-0145-FEDER- 000017, in its lines of research entitled I SAC, eo-financed by the European Regional Development Fund (ERDF) through NORTE 2020 (North Regional Operational Program 2014/2020).info:eu-repo/semantics/publishedVersio

    Il-22 increases the production of sfrp3 by fls in inflammatory joint diseases

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    Rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS) are inflammatory diseases with different bone remodeling patterns. Fibroblast-like synoviocytes (FLS) are cells involved in the transition from an acute and reparable phase to a chronic and persistent stage in these diseases. The distinction of joint phenotypes involves inflammatory cytokines such as tumor necrosis factor alpha (TNF-a), interleukin (IL)-17, and IL-22 directly or through key signaling pathways such as Wnt. To evaluate the role of FLS as the source of Wnt antagonists (sFRP3/FRZB and Dkk1) in the synovia, levels of TNF- a, IL-17, IL-22, Dkk1, and sFRP3 were measured by ELISA directly in the synovial fluid of patients with RA, PsA, or AS. Dkk1 and sFRP3 were also measured in the FLS culture supernatants after different inflammatory stimulus. sFRP3 and Dkk1 are constitutively expressed by FLS. IL-22 and sFRP3 were positively correlated (r=0.76; Po0.01) in synovial fluid. The stimulation of FLS with IL-22, but not TNF-alpha and IL-17, increased the production of sFRP3. No stimulus altered the basal expression of Dkk1. These results showed, for the first time, the ability of IL-22 to increase the expression of sFRP3/FRZB by human FLS in both in vitro and ex vivo models. This finding linked IL-22 to local inhibition of Wnt signaling and possibly to blockade of osteogenesis. Furthermore, FLS presented as a source of this inhibitor in synovial fluid, assigning to this cell a bone injury mechanism

    Transcriptome analysis shows activation of circulating CD8 T cells in patients with severe asthma

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    Background: Although previous studies have implicated tissue CD4 T cells in the development and maintenance of the inflammatory response in asthmatic patients, little is known about the role of CD8 T cells. There is now accumulating evidence that microRNAs and other noncoding RNAs are important regulators of T-cell function. Objectives: We sought to use transcriptomics to determine the activation state of circulating CD4 and CD8 T cells in patients with nonsevere and severe asthma. Methods: mRNA and noncoding RNA expression in circulating T cells was measured by means of microarray, quantitative real-time PCR, or both. Results: Comparison of mRNA expression showed widespread changes in the circulating CD8 but not CD4 T cells from patients with severe asthma. No changes were observed in the CD4 and CD8 T cells in patients with nonsevere asthma versus those in healthy control subjects. Bioinformatics analysis showed that the changes in CD8 T-cell mRNA expression were associated with multiple pathways involved in T-cell activation. As with mRNAs, we also observed widespread changes in expression of noncoding RNA species, including natural antisense, pseudogenes, intronic long noncoding RNAs (lncRNAs), and intergenic lncRNAs in CD8 T cells from patients with severe asthma. Measurement of the microRNA expression profile showed selective downregulation of miR-28-5p in CD8 T cells and reduction of miR-146a and miR-146b in both CD4 and CD8 T cells. Conclusions: Severe asthma is associated with the activation of circulating CD8 T cells but not CD4 T cells. This response is correlated with the downregulation of miR-146a/b and miR-28-5p, as well as changes in the expression of multiple species of lncRNA that might regulate CD8 T-cell function. © 2011 American Academy of Allergy, Asthma & Immunology

    Evaluation of HBV-Like circulation in wild and farm animals from Brazil and Uruguay

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    The origin of the hepatitis B virus is a subject of wide deliberation among researchers. As a result, increasing academic interest has focused on the spread of the virus in different animal species. However, the sources of viral infection for many of these animals are unknown since transmission may occur from animal to animal, human to human, animal to human, and human to animal. The aim of this study was to evaluate hepadnavirus circulation in wild and farm animals (including animals raised under wild or free conditions) from different sites in Brazil and Uruguay using serological and molecular tools. A total of 487 domestic wild and farm animals were screened for hepatitis B virus (HBV) serological markers and tested via quantitative and qualitative polymerase chain reaction (PCR) to detect viral DNA. We report evidence of HBsAg (surface antigen of HBV) and total anti-HBc (HBV core antigen) markers as well as low-copy hepadnavirus DNA among domestic and wild animals. According to our results, which were confirmed by partial genome sequencing, as the proximity between humans and animals increases, the potential for pathogen dispersal also increases. A wider knowledge and understanding of reverse zoonoses should be sought for an effective One Health response
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