1,742 research outputs found

    HTLV-I/II e doadores de sangue: determinantes associados à soropositividade em população de baixo risco

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    OBJECTIVE: Blood donors in Brazil have been routinely screened for HTLV-I/II since 1993. A study was performed to estimate the prevalence of HTLV-I/II infection in a low risk population and to better understand determinants associated with seropositivity. METHODS: HTLV-I/II seropositive (n=135), indeterminate (n=167) and seronegative blood donors (n=116) were enrolled in an open prevalence prospective cohort study. A cross-sectional epidemiological study of positive, indeterminate and seronegative HTLV-I/II subjects was conducted to assess behavioral and environmental risk factors for seropositivity. HTLV-I/II serological status was confirmed using enzyme-linked immunosorbent assay (EIA) and Western blot (WB). RESULTS: The three groups were not homogeneous. HTLV-I/II seropositivity was associated to past blood transfusion and years of schooling, a marker of socioeconomic status, and use of non-intravenous illegal drugs. CONCLUSIONS: The study results reinforce the importance of continuous monitoring and improvement of blood donor selection process.OBJETIVO: Doadores de sangue no Brasil têm sido avaliados sorologicamente para o HTLV-I/II desde 1993. Assim, realizou-se estudo para estimar a prevalência dessa infecção em população de baixo risco e para melhor compreender os determinantes associados à soropositividade. MÉTODOS: Doadores de sangue soropositivos (n=135), soroindeterminados (n=167) e soronegativos (n=116) foram arrolados como participantes de uma coorte aberta e prevalente. Estudo transversal dos participantes desses três grupos avaliou fatores de risco comportamentais e ambientais para soropositividade. O status sorológico foi definido usando a reação de EIA (enzyme linked immunosorbent assay) e o teste Western blot (WB). RESULTADOS: Os três grupos apresentaram heterogeneidade entre si. A soropositividade mostrou-se associada à história pregressa de transfusão de sangue, em nível educacional, como um marcador de condição socioeconômica e ao uso de drogas ilegais não endovenosas. CONCLUSÕES: Os resultados confirmam a importância de um monitoramento e refinamento do processo de seleção dos doadores de sangue

    Le genre Abies en Italie: écologie générale, gestion sylvicole et ressources génétiques.

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    International audienceLe genre Abies est représenté en Italie par deux espèces indigènes : A. alba et A. nebrodensis. A. alba (63.400 ha) est localisé dans les Alpes et dans les Apennins, jusqu'à l'Aspromonte, en Calabre. L'article fournit d'abord un aperçu historique, puis écologique de l'utilisation des sapinières. Il décrit ensuite la gestion naturelle des ressources génétiques. Importante bibliographie

    Experimental detection of quantum channel capacities

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    We present an effcient experimental procedure that certifies non vanishing quantum capacities for qubit noisy channels. Our method is based on the use of a fixed bipartite entangled state, where the system qubit is sent to the channel input. A particular set of local measurements is performed at the channel output and the ancilla qubit mode, obtaining lower bounds to the quantum capacities for any unknown channel with no need of a quantum process tomography. The entangled qubits have a Bell state configuration and are encoded in photon polarization. The lower bounds are found by estimating the Shannon and von Neumann entropies at the output using an optimized basis, whose statistics is obtained by measuring only the three observables σxσx\sigma_{x}\otimes\sigma_{x}, σyσy\sigma_{y}\otimes\sigma_{y} and σzσz\sigma_{z}\otimes\sigma_{z}.Comment: 5 pages and 3 figures in the principal article, and 4 pages in the supplementary materia

    Stacked optical antennas for plasmon propagation in a 5 nm-confined cavity

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    The sub-wavelength concentration and propagation of electromagnetic energy are two complementary aspects of plasmonics that are not necessarily co-present in a single nanosystem. Here we exploit the strong nanofocusing properties of stacked optical antennas in order to highly concentrate the electromagnetic energy into a 5 nm metal-insulator-metal (MIM) cavity and convert free radiation into guided modes. The proposed nano-architecture combines the concentration properties of optical nanoantennas with the propagation capability of MIM systems, paving the way to highly miniaturized on-chip plasmonic waveguiding

    Modulations of glycerophosphorylcholine and phosphorylcholine in Friend erythroleukemia cells upon in vitro-induced erythroid differentiation: a 31P NMR study

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    AbstractA 31P NMR study has been carried out on Friend erythroleukemia cells (FLC) induced to undergo erythroid differentiation in vitro. Significant levels of glycerophosphorylcholine (GroPCho) and phosphorylcholine (P-Cho) were identified both in the untreated cells and in their PCA extracts. In FLC treated 4 days in vitro with either dimethylsulfoxide (DMSO) or hexamethylenebisacetamide (HMBA), the intracellular concentration of P-Cho was markedly increased, whereas that of GroPCho appeared to be significantly reduced. HMBA was more effective than DMSO in producing this effect. The concomitant modulations of GroPCho and P-Cho in differentiated FLC suggest the hypothesis that erythroid differentiation involves modifications of the regulatory mechanisms controlling biosynthesis and catabolism of phospholipids

    Linear and nonlinear post-processing of numerically forecasted surface temperature

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    International audienceIn this paper we test different approaches to the statistical post-processing of gridded numerical surface air temperatures (provided by the European Centre for Medium-Range Weather Forecasts) onto the temperature measured at surface weather stations located in the Italian region of Puglia. We consider simple post-processing techniques, like correction for altitude, linear regression from different input parameters and Kalman filtering, as well as a neural network training procedure, stabilised (i.e. driven into the absolute minimum of the error function over the learning set) by means of a Simulated Annealing method. A comparative analysis of the results shows that the performance with neural networks is the best. It is encouraging for systematic use in meteorological forecast-analysis service operations

    Nicotinamide inhibits melanoma in vitro and in vivo

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    Background: Even though new therapies are available against melanoma, novel approaches are needed to overcome resistance and high-toxicity issues. In the present study the anti-melanoma activity of Nicotinamide (NAM), the amide form of Niacin, was assessed in vitro and in vivo. Methods: Human (A375, SK-MEL-28) and mouse (B16-F10) melanoma cell lines were used for in vitro investigations. Viability, cell-death, cell-cycle distribution, apoptosis, Nicotinamide Adenine Dinucleotide+ (NAD+), Adenosine Triphosphate (ATP), and Reactive Oxygen Species (ROS) levels were measured after NAM treatment. NAM anti-SIRT2 activity was tested in vitro; SIRT2 expression level was investigated by in silico transcriptomic analyses. Melanoma growth in vivo was measured in thirty-five C57BL/6 mice injected subcutaneously with B16-F10 melanoma cells and treated intraperitoneally with NAM. Interferon (IFN)-γ-secreting murine cells were counted with ELISPOT assay. Cytokine/chemokine plasmatic levels were measured by xMAP technology. Niacin receptors expression in human melanoma samples was also investigated by in silico transcriptomic analyses. Results: NAM reduced up to 90% melanoma cell number and induced: I) accumulation in G1-phase (40% increase), ii) reduction in S- A nd G2-phase (about 50% decrease), iii) a 10-fold increase of cell-death and 2.5-fold increase of apoptosis in sub-G1 phase, iv) a significant increase of NAD+, ATP, and ROS levels, v) a strong inhibition of SIRT2 activity in vitro. NAM significantly delayed tumor growth in vivo (p ≤ 0.0005) and improved survival of melanoma-bearing mice (p ≤ 0.0001). About 3-fold increase (p ≤ 0.05) of Interferon-gamma (IFN-γ) producing cells was observed in NAM treated mice. The plasmatic expression levels of 6 cytokines (namely: Interleukin 5 (IL-5), Eotaxin, Interleukin 12 (p40) (IL12(p40)), Interleukin 3 (IL-3), Interleukin 10 (IL-10) and Regulated on Activation Normal T Expressed and Secreted (RANTES) were significantly changed in the blood of NAM treated mice, suggesting a key role of the immune response. The observed inhibitory effect of NAM on SIRT2 enzymatic activity confirmed previous evidence; we show here that SIRT2 expression is significantly increased in melanoma and inversely related to melanoma-patients survival. Finally, we show for the first time that the expression levels of Niacin receptors HCAR2 and HCAR3 is almost abolished in human melanoma samples. Conclusion: NAM shows a relevant anti-melanoma activity in vitro and in vivo and is a suitable candidate for further clinical investigations
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