A joint experimental/theoretical study has been carried out on the putative MMA polymerization catalyzed by an yttrium isopropyloxide complex. Despite its high activity in lactone polymerization, this catalyst is found to be unreactive on methyl methacrylate (MMA) polymerization. This surprising result is rationalized using a computational approach at the DFT level. Indeed, the endothermicity o...

The decay characteristics of 90Sr-90Y ensure that the mother and daughter nuclides exist in radioactive equilibrium, unless they get discriminated on the basis of their chemical properties, as it happens during metabolism. Although bone is the ultimate organ of deposition, the two nuclides arrive at this target organ over different biokinetic pathways. As 90Y is not excreted, it goes through tr...

We have developed a semiautomatic procedure based on a sequential injection method for 90Sr/90Y determination that allows their radiochemical separation in about 30 min. The method has been tested using 90Sr/90Y solutions with activities lower than 12 Bq. The source is eluted in a pH = 6.5 medium through a MnO2-impregnated cotton filter, where 9OY is preconcentrated in preference by adsorption....

925. 45. Peacock-Villada E, Richardson BA, John-Stewart GC. Post-HAART outcomes in pediatric populations: comparison of resource-limited and developed countries. Pediatrics. 2011;127:e423 41. 46. Sutcliffe CG, van Dijk JH, Bolton C, Persaud D, Moss WJ. Effectiveness of antiretroviral therapy among HIV-infected children in sub-Saharan Africa. Lancet Infect Dis. 2008;8:477 89. 47. Leroy V, Malate...

The preparation of yttrium metal by the reduction of yttrium trifluoride with calcium is described. Alternate methods employing the formation of a low melting Y-Zn or Y-Mg intermediate alloy are evaluated and data on chemical and microscopic purity of the resulting metal are presented.