• Open Access close
• Closed Access close
• Open Source close
• Publications close
• Research software close
• Other research products close
• AU close
• BR close
• IE close

Photopolymerizable nanocomposites with good optical properties consisting of an acrylamide based photopolymer and zeolite nanoparticles (Beta, zeolite A, AlPO-18, silicalite-1 and zeolite L) were fabricated and characterized for holographic applications. The colloidal zeolite solutions used in this project were characterized by several techniques including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Raman spectroscopy to ensure their successful synthesis. The dependence of grating performances in these nanocomposites on recording intensity, spatial frequency and zeolite concentration were studied. It was found that the incorporation of silicalite-1 nanoparticles or a small amount of zeolite A nanoparticles (up to 1% wt.) leads to an improvement of the refractive index modulation of the gratings, while the addition of AlPO-18 and Beta nanoparticles to the photopolymer did not yield higher refractive index modulation. Despite a partial redistribution of nanoparticles during the holographic recording was observed, these results can be explained by the hydrophobic/ hydrophilic nature of the nanoparticles and their interactions/absence of interactions with the host photopolymer (studied by Visible, Raman and 13C NMR Spectroscopy). Gratings recorded in Beta and AlPO-18 nanocomposites were tested for holographic sensing. The interactions between zeolite L and sensitizing dyes was studied by visible spectroscopy for potential use in variable spectral sensitivity optical materials. A new photopolymerizable material was developed, with less toxic properties than acrylamide monomer and gratings recorded in this type of material were characterized for use in holographic sensor applications.

A new technique has been developed to determine in vivo airway compliance in humans that is specific to airway size and transpulmonary pressure, and can be represented as a three-dimensional surface. As yet, the ability of this technique to detect changes in specific airway compliance with disease status has not been demonstrated. The aim of this study was to assess whether this technique could determine changes in airway compliance which are thought to occur with altered smooth muscle tone in adults with asthma. Airway compliance was measured and displayed as a surface in adults with asthma before and after a reduction in smooth muscle tone by bronchodilator administration. Compliance, with respect to airway size, was calculated at three specific lung volumes; functional residual capacity (FRC), total lung capacity (TLC), and midway between FRC and TLC (MID). After bronchodilator, airway compliance increased at FRC and MID in the smaller airways (3 mm). Furthermore, airway compliance under both conditions was greater in the smaller airways compared to the larger airways. In conclusion, our method may have future utility in assessing changes in airway compliance in respiratory diseases such as asthma.

Although autophagy can eliminate some intracellular pathogens, others, e.g., Staphylococcus aureus, Salmonella, Mycoplasma bovis, can evade it. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway, a key regulator of autophagy, is involved in initiation and promotion of a range of pathological diseases. As the effects of M. bovis on the autophagic pathway are not well documented, our objective was to elucidate the effects of M. bovis infection on the PI3K-Akt-mTOR cellular autophagic pathway in bovine mammary epithelial cells (bMECs). Ultrastructure of bMECs infected with M. bovis was assessed with transmission electron microscopy, co-localization of LC3 puncta with M. bovis was confirmed by laser confocal microscopy, and autophagy-related indicators were quantified with Western blotting and RT-PCR. In M. bovis-infected bMECs, intracellular M. bovis was encapsulated by membrane-like structures, the expression level of LC3-II and Beclin1 protein decreased at the middle stage of infection, degradation of SQSTM1/P62 was blocked, autophagy of bMECs was inhibited, and PI3K-Akt-mTOR protein was activated by phosphorylation. Furthermore, the tumor suppressor PTEN can inhibit the PI3K-Akt signaling pathway through dephosphorylation of phosphatidylinositol 3,4,5-trisphosphate and may be important for cellular resistance to infection. In the present study, the number of intracellular M. bovis was inversely related to the change in the level of autophagy markers (e.g., LC3-II, SQSTM1/P62) within host cells induced by the low knockdown of Akt or PTEN. We concluded that M. bovis-infected bMECs alleviated cellular autophagy through a PI3K-Akt-mTOR pathway, and that PTEN acted as a protective gene regulating autophagy, a key step in controlling infection.

Este artigo analisa a cobertura jornalistica da Conferencia das Nacoes Unidas sobre o Desenvolvimento Sustentavel (Rio+20), tendo em vista a problematizacao em torno do conceito de acontecimento jornalistico, com base especialmente em Babo-Lanca (2006); Charaudeau (2006); Mouillaud (1997); Quere (2005; 2011) e Rebelo (2006). Sao analisadas as revistas Veja e Epoca, as duas com maior circulacao media entre as revistas semanais brasileiras. Como resultado, constata-se ter sido reiterante a utilizacao do gancho factual do acontecimento para discutir a tematica ambiental, porem nao foi realizada uma cobertura analitica da Rio+20 como acontecimento. Alem disso, as revistas se utilizaram da cobertura do acontecimento para reforcar a credibilidade. A analise demonstra ainda a criminalizacao e a ironia em relacao as manifestacoes ocorridas durante a conferencia e seus eventos paralelos.