28 research outputs found

    Planck 2015 results. XXVII. The Second Planck Catalogue of Sunyaev-Zeldovich Sources

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    We present the all-sky Planck catalogue of Sunyaev-Zeldovich (SZ) sources detected from the 29 month full-mission data. The catalogue (PSZ2) is the largest SZ-selected sample of galaxy clusters yet produced and the deepest all-sky catalogue of galaxy clusters. It contains 1653 detections, of which 1203 are confirmed clusters with identified counterparts in external data-sets, and is the first SZ-selected cluster survey containing > 10310^3 confirmed clusters. We present a detailed analysis of the survey selection function in terms of its completeness and statistical reliability, placing a lower limit of 83% on the purity. Using simulations, we find that the Y5R500 estimates are robust to pressure-profile variation and beam systematics, but accurate conversion to Y500 requires. the use of prior information on the cluster extent. We describe the multi-wavelength search for counterparts in ancillary data, which makes use of radio, microwave, infra-red, optical and X-ray data-sets, and which places emphasis on the robustness of the counterpart match. We discuss the physical properties of the new sample and identify a population of low-redshift X-ray under- luminous clusters revealed by SZ selection. These objects appear in optical and SZ surveys with consistent properties for their mass, but are almost absent from ROSAT X-ray selected samples

    Planck 2018 results. IV. Diffuse component separation

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    We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set of Planck frequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. The methodologies used to derive these maps follow closely those described in earlier papers, adopting four methods (Commander, NILC, SEVEM, and SMICA) to extract the CMB component, as well as three methods (Commander, GNILC, and SMICA) to extract astrophysical components. Our revised CMB temperature maps agree with corresponding products in the Planck 2015 delivery, whereas the polarization maps exhibit significantly lower large-scale power, reflecting the improved data processing described in companion papers; however, the noise properties of the resulting data products are complicated, and the best available end-to-end simulations exhibit relative biases with respect to the data at the few percent level. Using these maps, we are for the first time able to fit the spectral index of thermal dust independently over 3 degree regions. We derive a conservative estimate of the mean spectral index of polarized thermal dust emission of beta_d = 1.55 +/- 0.05, where the uncertainty marginalizes both over all known systematic uncertainties and different estimation techniques. For polarized synchrotron emission, we find a mean spectral index of beta_s = -3.1 +/- 0.1, consistent with previously reported measurements. We note that the current data processing does not allow for construction of unbiased single-bolometer maps, and this limits our ability to extract CO emission and correlated components. The foreground results for intensity derived in this paper therefore do not supersede corresponding Planck 2015 products. For polarization the new results supersede the corresponding 2015 products in all respects

    Planck 2018 results. XII. Galactic astrophysics using polarized dust emission

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    We present 353 GHz full-sky maps of the polarization fraction p, angle \u3c8, and dispersion of angles S of Galactic dust thermal emission produced from the 2018 release of Planck data. We confirm that the mean and maximum of p decrease with increasing NH. The uncertainty on the maximum polarization fraction, pmax=22.0% at 80 arcmin resolution, is dominated by the uncertainty on the zero level in total intensity. The observed inverse behaviour between p and S is interpreted with models of the polarized sky that include effects from only the topology of the turbulent Galactic magnetic field. Thus, the statistical properties of p, \u3c8, and S mostly reflect the structure of the magnetic field. Nevertheless, we search for potential signatures of varying grain alignment and dust properties. First, we analyse the product map S 7p, looking for residual trends. While p decreases by a factor of 3--4 between NH=1020 cm 122 and NH=2 71022 cm 122, S 7p decreases by only about 25%, a systematic trend observed in both the diffuse ISM and molecular clouds. Second, we find no systematic trend of S 7p with the dust temperature, even though in the diffuse ISM lines of sight with high p and low S tend to have colder dust. We also compare Planck data with starlight polarization in the visible at high latitudes. The agreement in polarization angles is remarkable. Two polarization emission-to-extinction ratios that characterize dust optical properties depend only weakly on NH and converge towards the values previously determined for translucent lines of sight. We determine an upper limit for the polarization fraction in extinction of 13%, compatible with the pmax observed in emission. These results provide strong constraints for models of Galactic dust in diffuse gas

    Planck 2018 results. XII. Galactic astrophysics using polarized dust emission

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    We present 353 GHz full-sky maps of the polarization fraction pp, angle ψ\psi, and dispersion of angles SS of Galactic dust thermal emission produced from the 2018 release of Planck data. We confirm that the mean and maximum of pp decrease with increasing NHN_H. The uncertainty on the maximum polarization fraction, pmax=22.0p_\mathrm{max}=22.0% at 80 arcmin resolution, is dominated by the uncertainty on the zero level in total intensity. The observed inverse behaviour between pp and SS is interpreted with models of the polarized sky that include effects from only the topology of the turbulent Galactic magnetic field. Thus, the statistical properties of pp, ψ\psi, and SS mostly reflect the structure of the magnetic field. Nevertheless, we search for potential signatures of varying grain alignment and dust properties. First, we analyse the product map S×pS \times p, looking for residual trends. While pp decreases by a factor of 3--4 between NH=1020N_H=10^{20} cm2^{-2} and NH=2×1022N_H=2\times 10^{22} cm2^{-2}, S×pS \times p decreases by only about 25%, a systematic trend observed in both the diffuse ISM and molecular clouds. Second, we find no systematic trend of S×pS \times p with the dust temperature, even though in the diffuse ISM lines of sight with high pp and low SS tend to have colder dust. We also compare Planck data with starlight polarization in the visible at high latitudes. The agreement in polarization angles is remarkable. Two polarization emission-to-extinction ratios that characterize dust optical properties depend only weakly on NHN_H and converge towards the values previously determined for translucent lines of sight. We determine an upper limit for the polarization fraction in extinction of 13%, compatible with the pmaxp_\mathrm{max} observed in emission. These results provide strong constraints for models of Galactic dust in diffuse gas

    Cytotoxicity and DNA damage in the neutrophils of patients with sickle cell anaemia treated with hydroxyurea

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    Hydroxyurea (HU) is the most important advance in the treatment of sickle cell anaemia (SCA) for preventing complications and improving quality of life for patients. However, some aspects of treatment with HU remain unclear, including their effect on and potential toxicity to other blood cells such as neutrophils. This study used the measurement of Lactate Dehydrogenase (LDH) and Methyl ThiazolTetrazolium (MTT) and the comet assay to investigate the cytotoxicity and damage index (DI) of the DNA in the neutrophils of patients with SCA using HU.In the LDH and MTT assays, a cytoprotective effect was observed in the group of patients treated, as well as an absence of toxicity. When compared to patients without the treatment, the SS group (n=20, 13 women and 07 men, aged 18-69 years), and the group of healthy individuals (AA) used as a control group (n=52, 28 women and 24 men, aged 19-60 years), The SSHU group (n=21, 11 women and 10 men, aged 19-63 years) showed a significant reduction (p20 months), demonstrating that despite the cytoprotective effects in terms of cell viability, the use of HU can induce DNA damage in neutrophils

    Quantificação de fatores de crescimento na pele de equinos tratada com plasma rico em plaquetas

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    O plasma rico em plaquetas (PRP) é um produto derivado da centrifugação do sangue total, sendo rico em fatores bioativos, como os de crescimento. Apesar da ampla utilização em processos cicatriciais, há controvérsia sobre a eficácia da terapia na cicatrização cutânea. O objetivo desse estudo foi quantificar e comparar a concentração dos fatores TGF-β1 e PDGF-BB no PRP, plasma sanguíneo e pele, durante diferentes fases do processo de cicatrização da pele tratada ou não com PRP. Foram utilizados sete equinos machos castrados, mestiços, hígidos, com idade entre 16 e 17 (16,14±0,63) anos. Três lesões em formato quadrangular (6,25cm²) foram produzidas cirurgicamente nas regiões glúteas direita e esquerda de todos os animais. Doze horas após indução das feridas, 0,5mL do PRP foi administrado em cada uma das quatro extremidades das feridas de uma das regiões glúteas (Grupo tratado = GT), escolhida aleatoriamente. A região contralateral foi utilizada como controle (GC). As feridas foram submetidas à limpeza diária com água Milli Q, e amostras foram obtidas mediante biópsias realizadas com Punch de 6mm. Foram obtidas seis biópsias de pele, sendo a primeira realizada logo após a produção da ferida (T0), e as demais com 1 (T1) 2 (T2) 7 (T3) e 14 (T4) dias após a indução da lesão. A sexta biópsia (T5) foi obtida após completo fechamento da pele, que ocorreu aproximadamente aos 37 dias (36,85±7,45, GC; 38,85±6,46, GT). Também foram obtidas amostras de sangue com EDTA em todos os tempos mencionados. A quantificação dos fatores de crescimento TGF-β1 e PDGF-BB na pele, PRP e plasma sanguíneo foi realizada pela técnica ELISA. Os dados foram analisados estatisticamente pelo teste t, correlação de Pearson e regressão, utilizando nível de significância de 5%. Não houve diferença entre os grupos, nos valores dos dois fatores de crescimento mensurados na pele, nos diferentes tempos. Também não houve correlação entre a quantidade dos fatores de crescimento presentes na pele e no plasma. Por outro lado, correlação positiva foi observada entre PRP e pele no grupo tratado, para os fatores de crescimento TGF-β1 (r=0,31) e PDGF-BB (r=0,38), bem como entre ambos os fatores de crescimento presentes no PRP (r=0,81). Considerando as concentrações dos fatores de crescimento no T0, os maiores valores cutâneos (p<0,05) do TGF-β1, em ambos os grupos, ocorreram nos tempos T3 e T5. Valores mais elevados (p<0,05) do PDGF-BB ocorreram no T4 (GT) e T5 (GC). No plasma não houve alteração nas concentrações desses fatores em relação ao T0, o que sugere que o PRP não acarreta efeito sistêmico, quando os procedimentos adotados na presente pesquisa são utilizados. A administração local de PRP no volume estudado, 12 h após indução cirúrgica de ferida cutânea na região glútea de equinos não ocasiona maiores concentrações dos fatores de crescimento TGF-β1 e PDGF-BB no plasma sanguíneo e pele, durante o processo de cicatrização

    Effect of CD8+ T-cell depletion on bronchial hyper-responsiveness and inflammation in sensitized and allergen-exposed Brown–Norway rats

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    We examined the role of CD8+ T cells in a Brown–Norway rat model of asthma, using a monoclonal antibody to deplete CD8+ T cells. Ovalbumin (OA)-sensitized animals were given anti-CD8 antibody (0·5 mg/rat) intravenously 1 week prior to exposure to 1% OA aerosol and were studied 18–24 hr after aerosol exposure. Following administration of anti-CD8 antibody, CD8+ cells were reduced to <1% of total lymphocytes in whole blood and in spleen. In sensitized animals, OA exposure induced bronchial hyper-responsiveness (BHR), accumulation of eosinophils, lymphocytes and neutrophils in bronchoalveolar lavage (BAL) fluid, and also an increase in tissue eosinophils and CD2+, CD4+ and CD8+T cells in airways. Anti-CD8 antibody caused a further increase in allergen-induced BHR (P < 0·03, compared with sham-treated animals), together with a significant increase in eosinophil number in BAL fluid (P < 0·05). While CD2+ and CD4+ T cells in airways were not affected by anti-CD8 treatment, the level of CD8+ T cells was significantly reduced in sensitized, saline-exposed animals (P < 0·04, compared with sham-treated rats), and sensitized and OA-challenged rats (P < 0·002, compared with sham-treated rats). Using reverse transcription–polymerase chain reaction, an increase of T helper (Th)2 cytokine [interleukin (IL)-4 and IL-5], and also of Th1 cytokine [interferon-γ (IFN-γ) and IL-2], mRNA in the lung of sensitized and OA-exposed animals was found; after CD8+ T-cell depletion, Th1 cytokine expression was significantly reduced (P < 0·02), while Th2 cytokine expression was unchanged. CD8+ T cells have a protective role in allergen-induced BHR and eosinophilic inflammation, probably through activation of the Th1 cytokine response
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