For the undoped sample, electrons at the bottom of the conductor band return to the ground state via a process of free exciton and defect intermediate level, and subsequently emit 3.2 and 2.4 eV photons. Furthermore, their intensities both increase while their positions are almost invariant with increasing excitation intensity. For the doped nanostructure, compositional inhomogeneity results in localization of nonequilibrium carriers and enhances the photoluminescence performance. The near-band edge emission shows higher emission efficiency and is
dominated by the transition of free electrons to free holes. Moreover, it also exhibits a power-dependent redshift and a broader and more asymmetric line shape on its lower-energy side with increasing excitation intensity. For the green emission in codoping ZnO nanostructures, the formation of deeper traps from the complexes of defects buy GW786034 and impurities results into a redshift to 523 nm. Additionally, its position remains invariant with increasing excitation intensity. It is proposed that the charge compensation, surface passivation, and carrier delocalization lead to the fully suppressed green emission at higher excitation intensity. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3060423]“
“Aims. PLX4032 To evaluate carotid intima-media thickness (cIMT)
and biomarkers of the osteoprotegerin/receptor activator of nuclear factor-kappa B ligand (OPG/RANKL) system in type 1 diabetes (TIDM) children and adolescents and controls. Subjects and Methods. Fifty six TIDM patients (mean +/- SD age: 12.0
+/- 2.7 years, diabetes duration: 5.42 +/- 2.87 years and HbAIc: 8.0 +/- 1.5%) and 28 healthymatched controls, were studied with anthropometric and laboratory measurements, including serumOPG, soluble RANKL (sRANKL) and cIMT. Results. Anthropometric, laboratory, and cIMT measurements were similar between TIDM youngsters and controls. However patients with longer diabetes duration (>/7.0 years) had indicatively higher cIMT (cIMT selleck = 0.49 vs 0.44 mm, P 0.072) and triglyceride levels than the rest of the patients (93.7 vs 64.6mg/dl, P 0.025). Both in the total study population (beta 0.418,beta 0.027) and among T1DM patients separately (beta 0.604,beta 0.013), BMI was the only factor associated with cIMT. BMI was further associated with OPGin both groups (beta-0.335,beta 0.003 and beta-0.356,beta 0.008 respectively), while sRANKL levels were not associated with any factor. Conclusions. BMI was the strongest independent predictor of cIMT among the whole population, and especially in diabetics, suggesting a possible synergistic effect of diabetes and adiposity on atherosclerotic burden. BMI was overall strongly associated with circulating OPG, but the causes of this association remain unclear.