Tracers
Mostrando 1-12 de 233 artigos, teses e dissertações.
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1. Evaluation of 10-minute post-injection 11C-PiB PET and its correlation with 18F-FDG PET in older adults who are cognitively healthy, mildly impaired, or with probable Alzheimer’s disease
Objective: Positron emission tomography (PET) allows in vivo evaluation of molecular targets in neurodegenerative diseases, such as Alzheimer’s disease. Mild cognitive impairment is an intermediate stage between normal cognition and Alzheimer-type dementia. In vivo fibrillar amyloid-beta can be detected in PET using [11C]-labeled Pittsburgh compound B (11C
Brazilian Journal of Psychiatry. Publicado em: 2022
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2. Influence of the Transport of Sea Spray on the Salinization of the Semiarid Region Waters (Bahia, Brazil)
The sea spray can be transported to long distances, reaching the semiarid regions. In this work, the rainwater and the atmospheric particulate matter were characterized by investigating the presence of sea spray in the atmosphere of the semiarid region of Bahia, Brazil, aiming to study the influence of its transport on the salinization of the waters of the r
J. Braz. Chem. Soc.. Publicado em: 2017-12
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3. Exploratory Analysis of Biodiesel by Combining Comprehensive Two-Dimensional Gas Chromatography and Multiway Principal Component Analysis
Comprehensive two-dimensional gas chromatography (GC×GC) was used in this work in order to reveal and identify minor compounds of several raw materials in biodiesel samples, which are not detected by conventional GC analysis. Multiway principal component analysis (MPCA) of the chromatographic profile allowed to identify compounds as C15:1n-3, C18:2n-6, C20:
J. Braz. Chem. Soc.. Publicado em: 2017-05
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4. Functional investigation of bone implant viability using radiotracers in a new model of osteonecrosis
OBJECTIVES: Conventional imaging methods are excellent for the morphological characterization of the consequences of osteonecrosis; however, only specialized techniques have been considered useful for obtaining functional information. To explore the affinity of radiotracers for severely devascularized bone, a new mouse model of isolated femur implanted in a
Clinics. Publicado em: 2016-10
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5. Photodegradation of a polypropylene filled with lanthanide complexes
This research aims at studying the photodegradation of a polypropylene formulation filled with lanthanide complexes. These complexes can be used as tracers for the identification of polymer materials in order to facilitate an high speed automatic sorting of plastic wastes for an economically efficient recycling. By paying attention to the evolution of carbon
Polímeros. Publicado em: 04/12/2015
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6. High shear dispersion of tracers in polyolefins for improving their detection
Abstract An efficient recycling of end-of-life products is of crucial interest from an economical and ecological point of view. However, the near infrared spectroscopy often used for the optic sorting processes is limited because of the absorption of carbon black present in black plastics and as it only sorts as a function of chemical formulas. The tracing t
Polímeros. Publicado em: 2015-10
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7. Mercury and stable isotopes (δ15N and δ13C) as tracers during the ontogeny of Trichiurus lepturus
Este estudo utilizou a concentração de mercúrio total (THg) e a assinatura isotópica (δ15N e δ13C) para avaliar a posição trófica e a área de alimentação de Trichiurus lepturus durante sua ontogenia no norte do Rio de Janeiro, sudeste do Brasil. A posição trófica de T. lepturus foi bem detectada pelo THg e δ15N com os espécimes sub-adultos p
Neotrop. ichthyol.. Publicado em: 2013-03
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8. PCA: uma ferramenta para identificação de traçadores químicos para água de formação e água de injeção associadas à produção de petróleo
This study describes the use of Principal Component Analysis to evaluate the chemical composition of water produced from eight oil wells in three different production areas. A total of 609 samples of produced water, and a reference sample of seawater, were characterized according to their levels of salinity, calcium, magnesium, strontium, barium and sulphate
Quím. Nova. Publicado em: 2013
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9. Traçadores isotópicos (Pb) e concentrações de metais em sedimentos superficiais: ferramentas na caracterização da poluição no setor oeste da baía de Sepetiba-RJ (SE do Brasil) / Isotopic tracers (Pb) and metal concentrations in surface sediments: tools for characterizing pollution in the west bay of Sepetiba-RJ (SE Brazil)
Este estudo teve como objetivo principal utilizar os teores de elementos-traço e análise isotópica de Pb (204Pb,206Pb,207Pb,208Pb) como ferramentas na caracterização da poluição da Baía de Sepetiba-RJ. As coletas de sedimento superficiais de fundo foram realizadas em três campanhas, em novembro de 2010, no setor oeste da Baía de Sepetiba RJ. A malh
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/05/2012
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10. Protein turnover, amino acid requirements and recommendations for athletes and active populations
Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after
Braz J Med Biol Res. Publicado em: 2012-10
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11. Diagnostic work-up of gastroenteropancreatic neuroendocrine tumors
Neuroendocrine tumors are a heterogeneous group of malignancies that present a diagnostic challenge. The majority of patients (more than 60%) present with metastatic disease at diagnosis. The diagnosis is based on histopathology, imaging, and circulating biomarkers. The histopathology should contain specific neuroendocrine markers such as chromogranin A, syn
Clinics. Publicado em: 2012
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12. Foliar nitrogen and changes in free amino acid composition of Solanum lycopersicum under cadmium toxicity: kinetics of 15NH4+
Glutamate metabolism and amino acid translocation were investigated in the control and cadmium stressed shoots of tomato (Solanum lycopersicum - 63/5 F1), using (15N) ammonium and (15N) glutamate tracers. Regardless of organ type, [15N] ammonium assimilation occurred via glutamine synthetase (EC 6.3.1.2), in the control and stressed plants, and it did not de
Braz. J. Plant Physiol.. Publicado em: 2012