Search results for " clusters"
showing 10 items of 1091 documents
Upconversion luminescence of a transparent glass ceramics with hexagonal Na(Gd,Lu)F4 nanocrystals
2017
Novel Er3+ doped transparent glass ceramics containing hexagonal Na(Gd,Lu)F4 nanocrystals were prepared from oxyfluoride glasses. The distribution of rare earth ions in the crystalline and glassy phase has been analyzed by X-ray diffraction and erbium luminescence decay kinetics measurement. A strong deviation of rare earth ion content in fluoride nanocrystals in comparison to the base glass has been observed. Preferential incorporation of Gd3+ over Lu3+ ions in the fluoride lattice leads to the stabilization of hexagonal Na(Gd,Lu)F4 structure and prevents the formation of cubic fluorite type solid solutions. A considerable enhancement of upconversion luminescence correlates with the format…
Tunable light emission by exciplex state formation between hybrid halide perovskite and core/shell quantum dots: Implications in advanced LEDs and ph…
2016
A perovskite–quantum dot exciplex has been detected, opening a broad range of possibilities for advanced optoelectronic devices.
Hybrid functional study of structural, electronic and magnetic properties of S-doped ZnO with and without neutral vacancy
2013
Abstract The structural and electronic properties of S-doped ZnO are investigated by density functional theory (DFT) and empirical pseudopotential method (EPM). Using the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional with an adjusted mixing coefficient α , we obtain a good agreement on lattice parameters and band gap energy with the available experimental data. We have also investigate the Zn-vacancy effects on the electronic and magnetic properties of S-doped ZnO. Our calculations demonstrate that S impurity prefers to be close to the cation vacancy in the apical position. The magnetic analysis with the HSE functional shows a triplet state character with a total magnetic moment of 1.81 μ…
Controlling the anisotropy of a van der Waals antiferromagnet with light
2020
Ultrafast optical control of magnetic anisotropy in a van der Waals antiferromagnet activates a sub-THz two-dimensional magnon.
Surface Chemistry Controls Magnetism in Cobalt Nanoclusters
2016
Magnetic properties of Co13 and Co55 nanoclusters, passivated by surface ligand shells that exhibit varying electronic interactions with the metal, are studied using density functional theory. The calculations show that the chemical nature of the bond between the ligand and the metal core (X-type or L-type) impacts the total magnetic moment of Co nanoclusters dramatically. Furthermore, the chemical identity of the ligand within each binding motif then provides a fine handle on the exhibited magnetic moment of the cluster. Thus, ligand shell chemistry is predicted to not only stabilize Co nanoclusters, but provide a powerful approach to control their magnetic properties, which combined enabl…
In-hospital death and adverse clinical events in elderly patients according to disease clustering: The REPOSI study
2010
OBJECTIVE: The aim of the study was to recognize clusters of diseases among hospitalized elderly and to identify groups of patients at risk of in-hospital death and adverse clinical events according to disease clustering. METHOD: This was a cross-sectional study conducted in 38 internal medicine and geriatric wards in Italy participating in the Registro Politerapie SIMI (REPOSI) study during 2008. The subjects were 1,332 inpatients aged 65 years or older. Clusters of diseases (i.e., two or more co-occurrent diseases) were identified using the odds ratios (OR) for the associations between pairs of conditions, followed by cluster analysis. Logistic regression models were used to evaluate the …
Limited cross-border infections in patients newly diagnosed with HIV in Europe
2013
Background: International travel plays a role in the spread of HIV-1 across Europe. It is, however, not known whether international travel is more important for spread of the epidemic as compared to endogenous infections within single countries. In this study, phylogenetic associations among HIV of newly diagnosed patients were determined across Europe.Results: Data came from the SPREAD programme which collects samples of newly diagnosed patients that are representative for national HIV epidemics. 4260 pol sequences from 25 European countries and Israel collected in 2002-2007 were included.We identified 457 clusters including 1330 persons (31.2% of all patients). The cluster size ranged bet…
Global burden of 87 risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019
2020
Background Rigorous analysis of levels and trends in exposure to leading risk factors and quantification of their effect on human health are important to identify where public health is making progress and in which cases current efforts are inadequate. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a standardised and comprehensive assessment of the magnitude of risk factor exposure, relative risk, and attributable burden of disease. Methods GBD 2019 estimated attributable mortality, years of life lost (YLLs), years of life lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 87 risk factors and combinations of risk factors, at the…
Marginalità e bioeconomia per lo sviluppo regionale
2014
La bioeconomia si riferisce ad un sistema che si fonda sull'uso intelligente delle risorse biologiche e rinnovabili provenienti dalla terra e dal mare come input industriali e della produzione di alimenti. La Commissione Europea, facendo seguito al lungo dibattito e al percorso effettuato negli ultimi anni sulla strada della sostenibilità, ha approvato la Strategia per l'innovazione per una crescita sostenibile e una bioeconomia per l'Europa. Il lavoro si propone di approfondire come la marginalità territoriale collegata alle disparità socio-economiche, possa essere elemento di vantaggio per la sfida proposta dalla bioeconomia in aree marginali come la Sicilia che hanno le potenzialità di c…
MARGINALITÀ E BIOECONOMIA PER LO SVILUPPO REGIONALE
2013
L'analisi dell'interazioni fra ecosistema e società assume un ruolo rilevante nello studio del sistema economico. La bioeconomia si riferisce ad un sistema che si fonda sull'uso intelligente delle risorse biologiche e rinnovabili provenienti dalla terra e dal mare come input industriali e della produzione di alimenti e mangimi. La bioeconomia, inoltre, comprende l'uso di rifiuti organici e di processi fondati su bioprodotti per un comparto industriale sostenibile. La Commissione Europa, facendo seguito al lungo dibattito e al percorso effettuato negli ultimi anni sulla strada della sostenibilità , ha approvato la strategia per L' innovazione per una crescita sostenibile: una bioeconomia per…