21 research outputs found

    Modelagem da temperatura do ar para o estado de São Paulo, Brasil

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    Spatial modelling of air temperature (maximum, mean and minimum) of the State of São Paulo (Brazil) was calculated by multiple regression analysis and ordinary kriging. Climatic data (mean values of five or more years) were obtained from 256 meteorological stations distributed uniformly over the State. The correlation between the climatic dependent variables, with latitude and altitude as independent variables was significant and could explain most of the spatial variability. The coefficients of determination (P < 0.05) varied in the range of 0.924 and 0.953, showing that multiple regression analysis is an accurate method for the modelling of air temperature for the State of São Paulo. Finally, these regression equations were used together with the kriged maps of the residual errors to build 15 digital maps of air temperature using a 0.5 km2 Digital Elevation Model in a Geographic Information System.Foram utilizadas técnicas de análise de regressão linear múltipla e krigagem ordinária para a modelagem espacial das temperaturas máximas, mínimas, médias do Estado de São Paulo (Brasil). Os dados climáticos foram obtidos de 256 estações climatológicas distribuídas na totalidade do Estado. O período mínimo das séries climáticas utilizadas foi de cinco anos. Os resultados das análises de regressão apresentaram uma boa correlação entre as variáveis dependentes analisadas (temperaturas médias, máximas e mínimas) com a latitude, e a altitude como variáveis independentes. Os coeficientes de determinação (P < 0,05) variam entre 0,924 e 0,953 indicando que a regressão múltipla é um método preciso de estimativa da temperatura do ar no Estado de São Paulo. As equações de regressão obtidas foram utilizadas, em conjunto com mapas dos resíduos interpolados por krigagem, para a elaboração de 15 mapas de temperatura do ar sobre um modelo de elevação digital de 0,5 km2 de resolução espacial com a ajuda de geoprocessamento.S

    Alternativas de secuestro de carbono orgánico en suelos y biomasa de Galicia

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    Se realiza una revisión de la capacidad de secuestro de Carbono por los suelos y biomasa de Galicia discutiendo posibles alternativas y poniendo de manifiesto su importancia ambiental y económica

    Quantum Confinement of Dirac Quasiparticles in Graphene Patterned with Sub-Nanometer Precision

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    Quantum confinement of graphene Dirac-like electrons in artificially crafted nanometer structures is a long sought goal that would provide a strategy to selectively tune the electronic properties of graphene, including bandgap opening or quantization of energy levels. However, creating confining structures with nanometer precision in shape, size, and location remains an experimental challenge, both for top-down and bottom-up approaches. Moreover, Klein tunneling, offering an escape route to graphene electrons, limits the efficiency of electrostatic confinement. Here, a scanning tunneling microscope (STM) is used to create graphene nanopatterns, with sub-nanometer precision, by the collective manipulation of a large number of H atoms. Individual graphene nanostructures are built at selected locations, with predetermined orientations and shapes, and with dimensions going all the way from 2 nm up to 1 µm. The method permits the patterns to be erased and rebuilt at will, and it can be implemented on different graphene substrates. STM experiments demonstrate that such graphene nanostructures confine very efficiently graphene Dirac quasiparticles, both in 0D and 1D structures. In graphene quantum dots, perfectly defined energy bandgaps up to 0.8 eV are found that scale as the inverse of the dot’s linear dimension, as expected for massless Dirac fermio

    Electrocatalytic performance and stability of nanostructured Fe–Ni pyrite-type diphosphide catalyst supported on carbon paper

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    A simple and effective method to prepare an active and stable nanostructured working electrode for electrochemical water splitting is described. Specifically, mixed Fe–Ni diphosphide was prepared by sputtering a 200-nm-thick layer of Permalloy onto carbon paper gas diffusion layer followed by gas transport phosphorization reaction. The mass density of the resultant diphosphide phase was established to be 1.1 mg/cm2. Energy-dispersive X-ray microanalysis shows that the actual elemental composition of the resultant ternary electrocatalyst is approximately Fe0.2Ni0.8P2, while the powder X-ray diffraction analysis confirms that the electrocatalyst crystallizes in NiP2 cubic pyrite-like structure. As a cathode for hydrogen evolution reaction (HER) in acidic and alkaline electrolytes, this earth-abundant electrode has exchange current densities of 6.84103 and 3.16103 mA/cm2 and Tafel slopes of 55.3 and 72.2 mV/dec, respectively. As an anode for oxygen evolution reaction (OER) in alkaline electrolyte, the electrode shows an exchange current density of 2.88104 mA/cm2 and Tafel slope of 49.3 mV/dec. The observed high activity of the electrode correlates well with its electronic structure, which was assessed by density functional theory (DFT) calculations. The stability of Fe0.2Ni0.8P2 electrocatalyst in HER and OER was evaluated by means of accelerated degradation test and chronopotentiometry. The results of these experiments elucidate partial dissolution and entire chemical transformation of Fe0.2Ni0.8P2 as the main mechanisms of the electrode degradation during HER and OER, respectively. Overall, our findings could facilitate the composition-based design of active, stable, and durable phosphide electrodes for electrochemical water splitting.We thank all members of the Nanomaterials Synthesis Unit at the INL for their fruitful scientific and technical input, as well as Dr. X. Wang for his help with the electrocatalytic data analysis. This investigation has benefited from the financial support provided by the European Union Horizon 2020 NMP programme through the CritCat project under grant agreement no. 686053, as well as ERDF funds through the Portuguese Operational Programme for Competitiveness and Internationalization (COMPETE 2020), and National Funds through the Portuguese Foundation for Science and Technology (FCT), under the PrintPV project PTDC/CTM-ENE/5387/2014 (grant agreement no. 016663). J.D.C. thanks the FCT PhD grant SFRH/BD/79393/2011, while J.L.L. thanks Marie-Curie-ITN607904-SPINOGRAPH project for the PhD grant

    PrediCTC, liquid biopsy in precision oncology: a technology transfer experience in the Spanish health system.

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    Purpose: Management of metastatic disease in oncology includes monitoring of therapy response principally by imaging techniques like CT-Scan. In addition to some limitations, the irruption of liquid biopsy and its application in personalized medicine has encouraged the development of more efficient technologies for prognosis and follow-up of patients in advanced disease. Methods: PrediCTC constitutes a panel of genes for the assessment of Circulating Tumor Cells (CTC) in metastatic colorectal cancer patients, with demonstrated improved efficiency compared to CT-Scan for the evaluation of early therapy response in a multicenter prospective study. In this work, we designed and developed a technology transfer strategy to define the market opportunity for an eventual implementation of PrediCTC in the clinical practice. Results: This included the definition of the regulatory framework, the analysis of the regulatory roadmap needed for CE mark, a benchmarking study, the design of a product development strategy, a revision of intellectual property, a cost-effectiveness study and an expert panel consultation. Conclusion: The definition and analysis of an appropriate technology transfer strategy and the correct balance among regulatory, financial and technical determinants are critical for the transformation of a promising technology into a viable technology, and for the decision of implementing liquid biopsy in the monitoring of therapy response in advanced disease.pre-print533 K

    Development and validation of a clinical score to estimate progression to severe or critical state in Covid-19 pneumonia hospitalized patients

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    The prognosis of a patient with Covid-19 pneumonia is uncertain. Our objective was to establish a predictive model of disease progression to facilitate early decision-making. A retrospective study was performed of patients admitted with Covid-19 pneumonia, classified as severe (admission to the intensive care unit, mechanic invasive ventilation, or death) or non-severe. A predictive model based on clinical, analytical, and radiological parameters was built. The probability of progression to severe disease was estimated by logistic regression analysis. Calibration and discrimination (receiver operating characteristics curves and AUC) were assessed to determine model performance. During the study period 1,152 patients presented with Covid-19 infection, of whom 229 (19.9%) were admitted for pneumonia. During hospitalization, 51 (22.3%) progressed to severe disease, of whom 26 required ICU care (11.4); 17 (7.4%) underwent invasive mechanical ventilation, and 32 (14%) died of any cause. Five predictors determined within 24 hours of admission were identified: Diabetes, Age, Lymphocyte count, SaO2, and pH (DALSH score). The prediction model showed a good clinical performance, including discrimination (AUC 0.87 CI 0.81, 0.92) and calibration (Brier score = 0.11). In total, 0%, 12%, and 50% of patients with severity risk scores ≤5%, 6-25%, and >25% exhibited disease progression, respectively. A simple risk score based on five factors predicts disease progression and facilitates early decision-making according to prognosis.Carlos III Health Institute, Spain, Ministry of Economy and Competitiveness (SPAIN) and the European Regional Development Fund (FEDER)Instituto de Salud Carlos II

    Alternativas de secuestro de carbono orgánico en suelos y biomasa de Galicia

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    Se realiza una revisión de la capacidad de secuestro de Carbono por los suelos y biomasa de Galicia discutiendo posibles alternativas y poniendo de manifiesto su importancia ambiental y económica.A review of the C sequestering capacity of soils and biomass of Galicia is presented here, together with a discussion of possible alternatives, and a description of the environmental and economical importance of this topic
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