178 research outputs found
Detecção e erradicação de videiras com sintomas do cancro bacteriano no Estado do Paraná.
Suplemento. Edição dos Resumos do 44 Congresso Brasileiro de Fitopatologia, Bento Gonçalves, ago. 2011
Nitrogen efficiency in wheat yield through the biopolymer hydrogel
ABSTRACT Nitrogen use efficiency in wheat biomass and grain yields can be favored by the biopolymer hydrogel. The objective of the study was to analyze the use of the biopolymer hydrogel applied to the seed in the optimization of fertilizer-N on wheat biomass and grain yields, under different conditions of agricultural year and succession systems of high and reduced release of residual-N. In the study, two experiments were conducted, with different farming systems, soybean/wheat and maize/wheat, one to quantify the biomass yield rate and the other to determine grain yield. The experiments were conducted in the years 2014 and 2015, in a randomized block design with four replicates in a 4 x 4 factorial scheme, corresponding to hydrogel doses (0, 30, 60 and 120 kg ha-1) added in the groove along with the seed and N fertilizer rates (0, 30, 60 and 120 kg ha-1), applied as top-dressing. It is possible to improve the fertilizer-N efficiency by wheat using the biopolymer hydrogel for the production of biomass and grains. The highest wheat yield per kilogram of N supplied is obtained with 30 and 60 kg ha-1 of hydrogel, regardless of the year and succession system.</jats:p
Leg blood flow measurements using venous occlusion plethysmography during head-up tilt
We tested whether venous occlusion plethysmography (VOP) is an appropriate method to measure calf blood flow (CBF) during head-up tilt (HUT). CBF measured with VOP was compared with superficial femoral artery blood flow as measured by Doppler ultrasound during incremental tilt angles. Measurements of both methods correlated well (r = 0.86). Reproducibility of VOP was fair in supine position and 30° HUT (CV: 11%–15%). This indicates that VOP is an applicable tool to measure leg blood flow during HUT, especially up to 30° HUT
Ecological interpretations of the leaf anatomy of amphibious species of Aeschynomene L. (Leguminosae - Papilionoideae)
BOLD Temporal Dynamics of Rat Superior Colliculus and Lateral Geniculate Nucleus following Short Duration Visual Stimulation
Background: The superior colliculus (SC) and lateral geniculate nucleus (LGN) are important subcortical structures for vision. Much of our understanding of vision was obtained using invasive and small field of view (FOV) techniques. In this study, we use non-invasive, large FOV blood oxygenation level-dependent (BOLD) fMRI to measure the SC and LGN's response temporal dynamics following short duration (1 s) visual stimulation. Methodology/Principal Findings: Experiments are performed at 7 tesla on Sprague Dawley rats stimulated in one eye with flashing light. Gradient-echo and spin-echo sequences are used to provide complementary information. An anatomical image is acquired from one rat after injection of monocrystalline iron oxide nanoparticles (MION), a blood vessel contrast agent. BOLD responses are concentrated in the contralateral SC and LGN. The SC BOLD signal measured with gradient-echo rises to 50% of maximum amplitude (PEAK) 0.2±0.2 s before the LGN signal (p<0.05). The LGN signal returns to 50% of PEAK 1.4±1.2 s before the SC signal (p<0.05). These results indicate the SC signal rises faster than the LGN signal but settles slower. Spin-echo results support these findings. The post-MION image shows the SC and LGN lie beneath large blood vessels. This subcortical vasculature is similar to that in the cortex, which also lies beneath large vessels. The LGN lies closer to the large vessels than much of the SC. Conclusions/Significance: The differences in response timing between SC and LGN are very similar to those between deep and shallow cortical layers following electrical stimulation, which are related to depth-dependent blood vessel dilation rates. This combined with the similarities in vasculature between subcortex and cortex suggest the SC and LGN timing differences are also related to depth-dependent dilation rates. This study shows for the first time that BOLD responses in the rat SC and LGN following short duration visual stimulation are temporally different. © 2011 Lau et al
Structural features of species of Asteraceae that arouse discussions about adaptation to seasonally dry environments of the Neotropics
Spectrophotometric and HPLC determination of deflazacort in pharmaceutical dosage forms
Deflazacort (DFZ) is a glucocorticoid used as an anti-inflammatory and immunosuppressant drug. No official methods are available for DFZ determination in pharmaceutical formulations. The objective of this study was to develop, validate and compare spectrophotometric (UV and colorimetric) and high-performance liquid chromatography (HPLC) methods, for the quantitative determination of DFZ in tablets and oral suspension. For the UV method, ethanol was used as the solvent, with detection at 244 nm. The colorimetric method was based on the redox reaction with blue tetrazolium in alkaline medium, with detection at 524 nm. The method by HPLC was carried out using a C18 column, mobile phase consisting of acetonitrile:water (80:20, v/v) with a flow rate of 1.0 mL min-1 and detection at 244 nm. The methods proved linear (r > 0.999), precise (RSD 97%). Statistical analysis of the results indicated that the UV and HPLC methods were statistically equivalent, while the values obtained for the colorimetric method differed significantly from the other methods.O deflazacorte (DFZ) é um fármaco glicocorticóide usado como antiinflamatório e imunossupressor. Métodos oficiais não estão disponíveis para a determinação de DFZ em formas farmacêuticas. Este estudo teve como objetivo desenvolver, validar e comparar métodos por espectrofotometria (UV e colorimetria) e cromatografia líquida de alta eficiência (CLAE), na determinação quantitativa de DFZ em comprimidos e suspensão oral. O método por UV utilizou etanol como solvente, com detecção em 244 nm. O método colorimétrico foi baseado na reação de redução com azul de tetrazólio em meio alcalino, com detecção em 524 nm. O método por CLAE utilizou coluna C18; fase móvel constituída de acetonitrila:água (80:20, v/v), com fluxo de 1,0 mL min-1 e detecção em 244 nm. Os métodos foram lineares (r > 0,999); precisos (RSD 97%). As análises estatísticas dos resultados obtidos indicaram que os métodos por UV e por CLAE foram estatisticamente equivalentes, enquanto os valores obtidos para o método colorimétrico diferiram significativamente dos demais métodos
Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes)
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