The x-ray photoelectron spectroscopy results provide evidence that Ag ions are mainly in the monovalent state and incorporated into the ZnO lattice at Zn2+ sites. It was found from the UV-visible spectra that the bandgap of ZnO decreases due to Ag doping. Excellent enhancement of luminescence properties in the green band is observed in Ag-doped ZnO nanocrystals. The origin of this
enhancement was discussed. It was demonstrated that oxygen vacancies and a spin-split impurity band are the key factors for deep level emissions. We believe that the present approach is a very simple but effective one for synthesis of novel ZnO complex micro/nanostructures, and these flowerlike Ag-doped ZnO nanocrystals may have good prospects in scientific and industrial applications. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3549826]“
“Little is known about the proportion this website of renal transplant candidates who are considered ineligible by the transplant center, the reasons of their ineligibility and their survival during dialysis. In this retrospective, single-center study of 445 adult
patients referred between 2001 and 2006, 36 (8%) were deemed ineligible for medical contraindications. The leading reason was cardiovascular (CV) (75%), specifically aorto-iliac, and/or limb vessels atheromatosis or calcifications; ischemic heart disease; or a combination thereof. Nine patients had other contraindications that were absolute for three of them; six patients displayed a combination of relative contraindications. selleck chemicals When compared to eligible patients (N = 409), those ineligible were significantly older (60 yr vs. 48), more often diabetics (50% vs. 15%), obese (39% vs. 17%) suffering from coronary artery disease (53% vs. 11%) and peripheral arterial disease (86% vs. 11%). Their primary nephropathy find more was more often diabetic and/or hypertensive/nephroangiosclerosis (61% vs. 23%), and their median dialysis vintage prior to evaluation was longer (29 months vs. 10, p < 0.0001). The actuarial survival of ineligible patients was significantly lower than that of
eligible patients (at five yr: 53% vs. 88%). Adequate control of CV risk factors before dialysis and early referral for transplantation might help to improve eligibility of renal transplant candidates.”
“Quasistatic measurements of room-temperature anelastic relaxation were used to characterize the properties of shear transformation zones (STZs) in amorphous Al(86.8)Ni(3.7)Y(9.5) in the dilute limit. Using a combination of nanoindenter cantilever bending and mandrel bend relaxation techniques, anelastic relaxation was measured over times ranging from 1 s to 3 x 10(7) s. Direct spectrum analysis yields relaxation-time spectra, which display seven distinct peaks. The results were analyzed using a linear dashpot-and-spring model, combined with transition-state theory, to yield several STZ properties.