H1 is found in all, and Z1 in all but one, of the samples in their as-received state but with a wide range of concentrations. However, annealing the samples in air up to 900 degrees C reduces the volume concentration range and the areal concentrations all become of order 10(11) cm(-2). Irradiation with gamma-rays does not affect their concentration. The Z1 centers are found to be the same as those previously observed in ZrO2 powders that were attributed to Zr3+ ions in coordinatively unsaturated (cus) sites at and/or near the surface. Our results are consistent with this model for Z1 and with an analogous model of cus Hf3+ for H1, H4 and Z4 are 4SC-202 chemical structure centers of isotropic
symmetry with values LB-100 in vivo that are both within +/-0.0004 of 2.0027; they are produced in all HfO2 and ZrO2 samples, respectively, that are heated in vacuum at >= 300 degrees C. Their concentration reaches a maximum of order 10(17) cm(-3) or 10(12) cm(-2) in the range of 550-750 degrees C. They are also most likely to be mainly at and/or near the surface and to involve an electron trapped in an oxygen vacancy cluster. The EPR spectra of H2 and Z2 are consistent with those of S = 1/2 centers of orthorhombic symmetry with principal g values about equal to or just less than g(e) suggesting that they
are trapped electron centers. The electrons produced by gamma-irradiation are trapped at precursors to H2 but are easily detrapped. Z2 centers also appear to be shallow electron traps. Their identity is uncertain; they have some characteristics of electrons trapped in oxygen vacancies and of CO2- radicals. H3 and Z3 are likely to involve holes trapped click here oil oxygen, possibly as O- and O-2(-) type centers, respectively, but their location in not known. Their concentration increases to an upper limit as the gamma-ray dose is increased and this shows that their precursors are trapping
charge generated by the gamma-rays. Like the H2 and Z2 centers, even annealing at 100 degrees C releases the charge but their precursors, at least in HfO2, are not destroyed. The significance of these centers is discussed. (C) 2009 American Institute of Physics. [doi:10.1063/1.3259405]“
“Background and aims: The role of diet in the aetiology of metabolic syndrome (MetS) is not well understood. The aim of the present study was to evaluate the relationship between adherence to the Mediterranean diet (MedDiet) and MetS.
Methods and results: A cross-sectional study was conducted with 808 high cardiovascular risk participants of the Reus PREDIMED Centre. MetS was defined by the updated National Cholesterol and Education Program Adult Treatment Panel III criteria.
An inverse association between quartiles of adherence to the MedDiet (14-point score) and the prevalence of MetS (P for trend < 0.001) was observed.