266 research outputs found

    Durability of interior renderings in schools: optimization of envelope insulation for mitigation of mould growth risk

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    A high standard education is, nowadays, a clear objective for anymodern society. In Portugal, the retrofit of educational buildings has an enormousrelevance as demonstrated by the Program for Retrofit and Upgrade of HighSchools. Educational buildings specific characteristics such as high occupancyrates and high amount of time children spend in classrooms make them a specialcase compared to other buildings. Mould growth on envelope surfaces is frequentlyobserved in these buildings, reducing the expected durability of renderingsand coatings. The present work consisted of two main lines of research: one ofsimulation and other of optimization. The simulation part included modelling ofInterior Surfaces Temperature, Indoor Air Temperature and Relative Humidityvariation, before and after a hypothetical retrofit process. Optimization techniqueswere applied in the definition of insulation thickness to be numerically tested in theafter retrofit scenario. The objective was to minimise insulation thickness ineach building element of the envelope. The constraints were derived from thecontrol of surface temperature values that would result in mould growth risk

    Structure of pair winds from compact objects with application to emission from bare strange stars

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    We present the results of numerical simulations of stationary, spherically outflowing, electron-positron pair winds, with total luminosities in the range 10^{34}- 10^{42} ergs/s. In the concrete example described here, the wind injection source is a hot, bare, strange star, predicted to be a powerful source of electron-positron pairs created by the Coulomb barrier at the quark surface. We find that photons dominate in the emerging emission, and the emerging photon spectrum is rather hard and differs substantially from the thermal spectrum expected from a neutron star with the same luminosity. This might help distinguish the putative bare strange stars from neutron stars.Comment: 4 pages, 6 figures, 1 table, added references, to appear in the proceedings of the conference "Isolated Neutron Stars: from the Surface to the Interior", London, UK, 24-28 April 200

    A nested case-control study of polychlorinated biphenyls, organochlorine pesticides, and thyroid cancer in the Janus Serum Bank cohort

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    Background: Polychlorinated biphenyls (PCBs) and organochlorine pesticides have been associated with altered thyroid hormone levels in humans, but their relationship with thyroid cancer is unknown. Methods: We conducted a nested case-control study of thyroid cancer in the Norwegian Janus Serum Bank cohort using pre-diagnostic blood samples from 1972 to 1985. Incident thyroid cancer (n = 108) was ascertained through 2008. Controls were matched 2:1 by age, date of blood draw, gender, and county. We used gas chromatography/mass spectrometry to quantify 36 PCB congeners and metabolites of pesticides DDT, chlordane, hexachlorocyclohexane, and hexachlorobenzene. PCBs and pesticide metabolites were evaluated individually and summed by degree of chlorination and parent compound, respectively. Odds ratios (OR) and 95% confidence intervals (CI) were computed using conditional logistic regression per specified increase in lipid-adjusted concentration. We additionally stratified analyses by birth cohort (1923–1932, 1933–1942, 1943–1957). Results: Increasing concentration of DDT metabolites (OR per 1000 ng/g = 0.80, 95%CI = 0.66–0.98) was inversely associated with thyroid cancer. Associations for PCBs were null or in inverse direction. We observed interactions for total PCBs, moderately-chlorinated PCBs, and chlordane metabolites with birth cohort (p ≤ 0.04). Among participants born 1943–1957, total PCBs (OR per 100 ng/g = 1.25, 95%CI = 1.00–1.56), moderately-chlorinated PCBs (OR per 100 ng/g = 1.31, 95%CI = 1.01–1.70), and chlordane metabolites (OR per 10 ng/g = 1.78, 95%CI = 1.09–2.93) were positively associated with thyroid cancer. For individuals born before 1943, associations were generally null or in the inverse direction. Conclusions: Emissions of PCBs and OC pesticides varied over time. Different risk patterns by birth cohort suggest the potential importance of timing of exposure in thyroid cancer risk. Further evaluation of these associations is warranted

    Deglutarylation of glutaryl-CoA dehydrogenase by deacylating enzyme SIRT5 promotes lysine oxidation in mice

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    A wide range of protein acyl modifications has been identified on enzymes across various metabolic processes; however, the impact of these modifications remains poorly understood. Protein glutarylation is a recently identified modification that can be nonenzymatically driven by glutaryl-CoA. In mammalian systems, this unique metabolite is only produced in the lysine and tryptophan oxidative pathways. To better understand the biology of protein glutarylation, we studied the relationship between enzymes within the lysine/tryptophan catabolic pathways, protein glutarylation, and regulation by the deglutarylating enzyme sirtuin 5 (SIRT5). Here, we identify glutarylation on the lysine oxidation pathway enzyme glutaryl-CoA dehydrogenase (GCDH) and show increased GCDH glutarylation when glutaryl-CoA production is stimulated by lysine catabolism. Our data reveal that glutarylation of GCDH impacts its function, ultimately decreasing lysine oxidation. We also demonstrate the ability of SIRT5 to deglutarylate GCDH, restoring its enzymatic activity. Finally, metabolomic and bioinformatic analyses indicate an expanded role for SIRT5 in regulating amino acid metabolism. Together, these data support a feedback loop model within the lysine/tryptophan oxidation pathway in which glutaryl-CoA is produced, in turn inhibiting GCDH function via glutaryl modification of GCDH lysine residues and can be relieved by SIRT5 deacylation activity

    Scaling Up ART Adherence Clubs in the Public Sector Health System in the Western Cape, South Africa: a Study of the Institutionalisation of a Pilot Innovation

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    In 2011, a decision was made to scale up a pilot innovation involving ‘adherence clubs’ as a form of differentiated care for HIV positive people in the public sector antiretroviral therapy programme in the Western Cape Province of South Africa. In 2016 we were involved in the qualitative aspect of an evaluation of the adherence club model, the overall objective of which was to assess the health outcomes for patients accessing clubs through epidemiological analysis, and to conduct a health systems analysis to evaluate how the model of care performed at scale. In this paper we adopt a complex adaptive systems lens to analyse planned organisational change through intervention in a state health system. We explore the challenges associated with taking to scale a pilot that began as a relatively simple innovation by a non-governmental organisation

    Proteomics approaches to fibrotic disorders

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    This review provides an introduction to mass spectrometry based proteomics and discusses several proteomics approaches that are relevant in understanding the pathophysiology of fibrotic disorders and the approaches that are frequently used in biomarker discovery

    Differentially expressed genes in a flock of Chinese local-breed chickens infected with a subgroup J avian leukosis virus using suppression subtractive hybridization

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    Avian leukosis virus subgroup J (ALV-J) is a new type of virus that mainly induces myeloid leukosis (ML) in chickens. To further elucidate the pathogenesis of ALV-J infection and tumor development, expression profiles from the bone marrow tissue of 15 infected and 18 non-infected birds from a local-breed poultry-farm under naturally infected conditions, were analyzed by suppression-subtractive hybridization. The birds were diagnosed as ML+ (or ML-) by specific ALV-J detection methods, involving serological tests for antigens and antibodies, and RT-PCR to detect viral RNA. A total of 59 partial gene sequences were revealed by differential screening of 496 forward and 384 reverse subtracted cDNA clones. Of these, 22 identified genes, including 8 up-regulated and 14 down-regulated, were related to immune functions, these genes being, MHC B-G antigen, translationally-controlled tumor protein (TPT1/TPTC), transferrin and ferritin, hemoglobin and Carbonic anhydrase. Four of the down-regulated genes were selected for further analysis, in view of their predicted roles in infection and immunity by real-time qRT-PCR, using RNA collected from the same birds as those used for SSH. The four genes were expressed at significantly lower levels (p < 0.001) in ALV-J infected birds than in non-infected ones

    Intracellular iron uptake is favored in Hfe-KO mouse primary chondrocytes mimicking an osteoarthritis-related phenotype

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    HFE-hemochromatosis is a disease characterized by a systemic iron overload phenotype mainly associated with mutations in the HFE protein (HFE) gene. Osteoarthritis (OA) has been reported as one of the most prevalent complications in HFE-hemochromatosis patients, but the mechanisms associated with its onset and progression remain incompletely understood. In this study, we have characterized the response to high iron concentrations of a primary culture of articular chondrocytes isolated from newborn Hfe-KO mice and compared the results with that of a similar experiment developed in cells from C57BL/6 wild-type (wt) mice. Our data provide evidence that both wt- and Hfe-KO-derived chondrocytes, when exposed to 50 mu M iron, develop characteristics of an OA-related phenotype, such as an increased expression of metalloproteases, a decreased extracellular matrix production, and a lower expression level of aggrecan. In addition, Hfe-KO cells also showed an increased expression of iron metabolism markers and MMP3, indicating an increased susceptibility to intracellular iron accumulation and higher levels of chondrocyte catabolism. Accordingly, upon treatment with 50 mu M iron, these chondrocytes were found to preferentially differentiate toward hypertrophy with increased expression of collagen I and transferrin and downregulation of SRY (sex-determining region Y)-box containing gene 9 (Sox9). In conclusion, high iron exposure can compromise chondrocyte metabolism, which, when simultaneously affected by an Hfe loss of function, appears to be more susceptible to the establishment of an OA-related phenotype.European Regional Development FundEuropean Union (EU) [EMBRC.PT Alg-01-0145-FEDER-022121, Norte-01-0145-FEDER-000012]Fundacao para a Ciencia e a TecnologiaPortuguese Foundation for Science and Technology [SFRH/BD/77056/2011]Portuguese Foundation for Science and TechnologyPortuguese Foundation for Science and TechnologyPortuguese Science and Technology FoundationPortuguese Foundation for Science and Technologyinfo:eu-repo/semantics/publishedVersio
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