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991.
992.
Multielement analysis in serum of healthy population of the metropolitan region of Rio de Janeiro in Brazil by SRTXRF
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Catarine G. L. Canellas Silvia M. F. Carvalho Roberta G. Leitão Alfredo V. B. Bellido Marcelino J. Anjos Ricardo T. Lopes 《X射线光谱测定》2016,45(1):14-18
The determination of multielemental concentrations in physiological fluids is of considerable interest in clinical chemistry. Since it has been established these levels in human serum can be utilized as indicators for several pathological conditions. The multielement composition determination in human serum is important for the investigation of their role in human physiology and metabolism. From this research, more detailed studies on the health of individuals living in the metropolitan region of the state of Rio de Janeiro can be realized in order to improve the quality of life of these individuals. We studied 180 healthy volunteers (80 males and 100 females) aged 19 to 60 years. All the serum samples had been collected of people who live in the urban area of Rio de Janeiro City/Brazil. The measurements were performed at the X‐Ray Fluorescence Beamline at the Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, São Paulo. We were able to determine the concentrations of the following 11 elements: Na, P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. In this study, we used statistical analysis for the principal components. We were able to verify the presence of two factors that divided the elements into two groups: group 1 formed by elements: Cl, K, S and Ca and group 2 by elements Cu and Zn. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
993.
994.
Dulce Alonso 《Tetrahedron letters》2007,48(6):907-910
New 1-formamido-2-siloxy-1,3-butadienes have been generated from 1,3-dichloroacetone by means of phosphorane formation, formamido substitution, Wittig olefination and silylation. The procedure demonstrates the utility and versatility of this methodology for the formation of polysubstituted dienes, designed as useful building blocks for the synthesis of polycyclic alkaloids and related analogues. 相似文献
995.
Griselda García Miguel Kiwi José Mejía-López Ricardo Ramírez 《Journal of magnetism and magnetic materials》2010,322(21):3329-3332
The magnitude of the exchange bias field of patterned systems exhibits a notable increase in relation to the usual bilayer systems, where a continuous ferromagnetic film is deposited on an antiferromagnet insulator. Here we develop a model, and implement a Monte Carlo calculation, to interpret the experimental observations which is consistent with experimental results, on the basis of assuming a small fraction of spins pinned ferromagnetically in the antiferromagnetic interface layer. 相似文献
996.
Ana Lí a Durá n Ricardo Estrada 《Proceedings of the American Mathematical Society》1999,127(6):1745-1751
We identify a class of functions for which an extension of the well known integral test holds, namely, the series is Cesàro summable if and only if the integral is. We also give the corresponding multidimensional results.
997.
We obtain error estimates for finite element approximations of the lowest degree valid uniformly for a class of three-dimensional narrow elements. First, for the Lagrange interpolation we prove optimal error estimates, both in order and regularity, in for . For it is known that this result is not true. Applying extrapolation results we obtain an optimal order error estimate for functions sligthly more regular than . These results are valid both for tetrahedral and rectangular elements. Second, for the case of rectangular elements, we obtain optimal, in order and regularity, error estimates for an average interpolation valid for functions in with and .
998.
Leovigildo Alonso Tarrí o Ana Jeremí as Ló pez Marí a José Souto Salorio 《Transactions of the American Mathematical Society》2003,355(6):2523-2543
We associate a -structure to a family of objects in , the derived category of a Grothendieck category . Using general results on -structures, we give a new proof of Rickard's theorem on equivalence of bounded derived categories of modules. Also, we extend this result to bounded derived categories of quasi-coherent sheaves on separated divisorial schemes obtaining, in particular, Belinson's equivalences.
999.
Fernandes PA Carvalho AT Marques AT Pereira AL Madeira AP Ribeiro AS Carvalho AF Ricardo ET Pinto FJ Santos HA Mangericão HD Martins HM Pinto HD Santos HR Moreira IS Azeredo MJ Abreu RP Oliveira RM Sousa SF Silva RJ Mourão ZS Ramos MJ 《Journal of computer-aided molecular design》2003,17(7):463-473
New designs for Magnetic Resonance Imaging contrast agents are presented. Essentially, they all are host–guest inclusion complexes between -cyclodextrins and polyazamacrocycles of gadolinium (III) ion. Substitutions have been made to the host to optimise the host–guest association. Molecular mechanics calculations have been performed, using the UFF force field for metals, to decide on the suitability of the substitutions, and to evaluate the host–guest energies of association. Interesting general conclusions have been obtained, concerning the improvement of Magnetic Resonance Imaging contrast agents; namely, a set of rational methodologies have been deduced to improve the association between the gadolinium (III) chelates and the cyclodextrins, and their efficiency is demonstrated with a large set of substituted complexes, opening new doors to increase the diagnostic capabilities of Magnetic Resonance Imaging. 相似文献
1000.
B. Konopelchenko L. Martínez Alonso E. Medina 《Theoretical and Mathematical Physics》2002,133(2):1529-1538
A
formalism for studying dispersionless integrable hierarchies is applied to the dispersionless KP (dKP) hierarchy. We relate this formalism to the theory of quasiconformal mappings on the plane and present some classes of explicit solutions of the dKP hierarchy. 相似文献