Search results for "mines"
showing 10 items of 2609 documents
Analytical Performance Issues
2014
Contaminated hospital surfaces have been demonstrated to be an important environmental reservoir of microorganisms that can increase the risk of nosocomial infection in exposed patients. As a consequence, cleaning and disinfecting hospital environments play an important role among strategies for preventing healthcare-associated colonization and infections. The aim of the present study was to evaluate whether adenosine triphosphate (ATP) presence, measured by bioluminescence methods, can predict microbiological contamination of hospital surfaces. The study was carried out between September and December 2012 at the University Hospital "P. Giaccone" of Palermo. A total of 193 randomly selected…
Modeling of defects and surfaces in perovskite ferroelectrics
2002
The results of electronic structure calculations for different terminations of SrTiO3 (100) and (110) perovskite thin films are discussed. These calculations are based on the ab initio Hartree-Fock (HF) method and Density Functional Theory (DFT). Results are compared with previous ab initio plane-wave LDA and classical Shell Model (SM) calculations. Calculated considerable increase of the Ti – O chemical bond covalency nearby the surface is confirmed by experimental data. Our quantum chemical calculations performed by means of the intermediate neglect of differential overlap (INDO) method confirm the existence of self-trapped electrons in KNbO3, KTaO3 and BaTiO3 crystals. The relevant latti…
Low-Cost Synthesis of Smart Biocompatible Graphene Oxide Reduced Species by Means of GFP.
2015
The aim of this work is focused on the engineering of biocompatible complex systems composed of an inorganic and bio part. Graphene oxide (GO) and/or graphite oxide (GtO) were taken into account as potential substrates to the linkage of the protein such as Anemonia sulcata recombinant green fluorescent protein (rAsGFP). The complex system is obtained through a reduction process between GO/GtO and rAsGFP archiving an environmentally friendly biosynthesis. Spectroscopic measurements support the formation of reduced species. In particular, photoluminescence shows a change in the activity of the protein when a bond is formed, highlighted by a loss of the maximum emission signal of rAsGFP and a …
Effects of high pressure thermal treatments in oxygen and helium atmospheres on amorphous silicon dioxide and its radiation hardness
2009
The effects of thermal treatments at similar to 400 degrees C in oxygen or helium atmospheres at similar to 180 baron the radiation hardness of amorphous SiO(2) are studied. The generation efficiency of several point defects under gamma irradiation is compared to that of the untreated material. All the effects on point defects generation here observed can be explained in terms of changes in the precursor sites. In particular it has been observed that the thermal treatments can change the precursors sites of point defects both through temperature and pressure related processes, not depending on the atmosphere, and through oxygen related processes creating oxygen excess sites. The presence of…
DNA-binding of zinc(II) and nickel(II) salphen-like complexes extrapolated at 1 M salt concentration: Removing the ionic strength bias in physiologic…
2020
Abstract The DNA-binding of two salphen-like metal complexes of nickel(II) (1) and zinc(II) (2) was investigated in different ionic strength solutions by absorption spectroscopy. The data analysis allowed us to obtain the values of their extrapolated DNA-binding constant in physiological conditions, with DNA-binding strength in the order Ni > Zn, and to give relative weight to the electrostatic and non-electrostatic contributions to their DNA-interaction.
On the Low-Lying Excited States ofsym-Triazine-Based Herbicides
2005
We report a joint computational and luminescence study on the low-lying excited states of sym-triazines, namely, 1,3,5-triazine (1) and the ubiquitous herbicides atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (2)] and ametryn [6-methylthio-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (3)]. Geometrical structures, energetics, and transition and state properties of I and 2 were computed at the TD-DFT, CASSCF, and CASPT2 levels of theory. The fluorescence and phosphorescence emission spectra, lifetimes, and fluorescence quantum yields were measured for the three compounds, and from these, the energies of the lowest excited states and their corresponding radiative rates…
Luminescent osmium(II) bi-1,2,3-triazol-4-yl complexes: photophysical characterisation and application in light-emitting electrochemical cells
2016
The series of osmium(II) complexes [Os(bpy)3-n(btz)n][PF6]2 (bpy = 2,2’-bipyridyl, btz = 1,1’-dibenzyl-4,4’-bi-1,2,3-triazolyl, 1 n = 0, 2 n = 1, 3 n = 2, 4 n = 3), have been prepared and characterised. The progressive replacement of bpy by btz leads to blue-shifted UV-visible electronic absorption spectra, indicative of btz perturbation of the successively destabilised bpy-centred LUMO. For 4, a dramatic blue-shift relative to the absorption profile for 3 is observed, indicative of the much higher energy LUMO of the btz ligand over that of bpy, mirroring previously reported data on analogous ruthenium(II) complexes. Unlike the previously reported ruthenium systems, heteroleptic complexes 2…
Neutron-induced defects in F-doped fibers
2014
We present a study on 0.8 MeV neutron-induced defects up to fluences of 1017 n/cm² in fluorine doped fibers by using electron paramagnetic resonance, optical absorption and confocal micro-luminescence techniques. Our results allow to address the microscopic mechanisms leading to the generation of some Silica-related point-defects such as E’, H(I), POR and NBOH Centers.
Integration of polyamins in the cold acclimation response
2011
8 páginas, 1 figura, 3 tablas -- PAGS nros. 31-38
Multivariate standardisation for non-linear calibration range in the chemiluminescence determination of chromium.
2006
Multivariate standardisation is proposed for the successful chemiluminescence determination of chromium based on luminol-hydrogen peroxide reaction. In an extended concentration range, non-linear calibration model is needed. The studied instrumental situations were different detection cells, instruments, assemblies, time and their possible combinations. Chemiluminescence kinetic registers have been transferred using piecewise direct standardisation (PDS) method. The optimisation of transfer parameters has been carried out based on the prediction residual error criteria. Non-linear principal component regression (NL-PCR) and non-linear partial least square regression (NL-PLS) were chosen for…