3 resultados para Rich Description Method
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
RNA isolation is essential to study gene expression at the molecular level. However, RNA isolation is difficult in organisms (plants and algae) that contain large amounts of polysaccharides, which co-precipitate with RNA. Currently, there is no commercial kit available, specifically for the isolation of high-quality RNA from these organisms. Furthermore, because of the large amounts of polysaccharides, the common protocols for RNA isolation usually result in poor yields when applied to algae. Here we describe a simple method for RNA isolation from the marine red macroalga Gracilaria tenuistipitata var. liui Zhang et Xia (Rhodophyta), which can be applied to other plants and algae.
Resumo:
The bare nucleus S(E) factors for the (2)H(d, p)(3)H and (2)H(d.n)(3)He reactions have been measured for the first time via the Trojan Horse Method off the proton in (3)He from 1.5 MeV down to 2 key. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4 +/- 1.8 MeVb for (3)H + p and 60.1 +/- 1.9 MeV b for (3)He + n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors. (C) 2011 Elsevier By. All rights reserved.
Resumo:
Inside the `cavernous sinus` or `parasellar region` the human internal carotid artery takes the shape of a siphon that is twisted and torqued in three dimensions and surrounded by a network of veins. The parasellar section of the internal carotid artery is of broad biological and medical interest, as its peculiar shape is associated with temperature regulation in the brain and correlated with the occurrence of vascular pathologies. The present study aims to provide anatomical descriptions and objective mathematical characterizations of the shape of the parasellar section of the internal carotid artery in human infants and its modifications during ontogeny. Three-dimensional (3D) computer models of the parasellar section of the internal carotid artery of infants were generated with a state-of-the-art 3D reconstruction method and analysed using both traditional morphometric methods and novel mathematical algorithms. We show that four constant, demarcated bends can be described along the infant parasellar section of the internal carotid artery, and we provide measurements of their angles. We further provide calculations of the curvature and torsion energy, and the total complexity of the 3D skeleton of the parasellar section of the internal carotid artery, and compare the complexity of this in infants and adults. Finally, we examine the relationship between shape parameters of the parasellar section of the internal carotid artery in infants, and the occurrence of intima cushions, and evaluate the reliability of subjective angle measurements for characterizing the complexity of the parasellar section of the internal carotid artery in infants. The results can serve as objective reference data for comparative studies and for medical imaging diagnostics. They also form the basis for a new hypothesis that explains the mechanisms responsible for the ontogenetic transformation in the shape of the parasellar section of the internal carotid artery.