261 resultados para Nostradamus, 1503-1566.
Resumo:
The efficiency of solar-energy-conversion devices depends on the absorption region and intensity of the photon collectors. Organic chromophores, which have been widely stabilized on inorganic semiconductors for light trapping, are limited by the interface between the chromophore and semiconductor. Herein we report a novel orange zinc germanate (Zn-Ge-O) with a chromophore-like structure, by which the absorption region can be dramatically expanded. Structural characterizations and theoretical calculations together reveal that the origin of visible-light response can be attributed to the unusual metallic Ge-Ge bonds which act in a similar way to organic chromophores. Benefiting from the enhanced light harvest, the orange Zn-Ge-O demonstrates superior capacity for solar-driven hydrogen production.
Resumo:
A highly luminescent and sensitive terbium complex of a ligand comprising of a phthalimide group appended to a DO3A moiety is an active pH sensor that is conditional on its previous pH. © 2012 The Royal Society of Chemistry.
Resumo:
The preparation of Janus fibers using a new side-by-side electrospinning process is reported. By manipulating the angle between the two ports of the spinneret emitting the working fluids, Janus nanofibers with tunable structures in terms of width, interfacial area and also volume of each side can be easily fabricated.
Resumo:
The ammoxidation of ethanol is investigated as a renewable process for the production of acetonitrile from a bio-feedstock. Palladium catalysts are shown to be active and very selective (>99%) to this reaction at moderate to low temperatures (150-240 °C), with acetonitrile yields considered a function of Pd morphology. Further investigations reveal that the stability of these catalysts is influenced by an unselective product, and that any deactivation observed is reversible. Interpretation of this deactivation allows operating conditions to be defined for the stable, high yielding production of acetonitrile from ethanol.
Resumo:
Background: Little is known about prescribing appropriateness for community-dwelling people with dementia (PWD).
Objective To estimate potentially inappropriate prescribing (PIP) prevalence among PWD in primary care in Northern Ireland, and to investigate associations between PIP and polypharmacy, age and gender.
Methods: A retrospective cross-sectional study was conducted, using data from the Enhanced Prescribing Database. Patients were eligible if a medicine indicated for dementia management was dispensed to them during 01/01/2013 – 31/12/2013. Polypharmacy was indicated by use of ≥4 repeat medications from different drug groups. A subset of the Screening Tool of Older Persons Potentially Inappropriate Prescriptions (STOPP) criteria, comprising 36 indicators, was applied to the dataset. Overall prevalence of PIP and the prevalence per each STOPP criterion was calculated as a proportion of all eligible persons in the dataset. Logistic regression was used to investigate associations between PIP, polypharmacy, age and gender.
Results: The study population comprised 6826 patients. Polypharmacy was observed in 81.5% (n=5564) of patients. PIP prevalence during the study period was 64.4% (95% CI 63.2 – 65.5; n=4393). The most common instance of PIP was the use of anticholinergic/antimuscarinic medications (n=1718; 25.2%; 95% CI 24.2 – 26.2). In multivariable analyses, both polypharmacy and gender (being female) were associated with PIP, with odds ratios of 7.6 (95% CI 6.6 – 8.7) and 1.3 (95% CI 1.2 – 1.4) respectively. No association was observed between PIP and age, after adjustments for gender and polypharmacy.
Conclusion: This study identified a high prevalence of PIP in community-dwelling PWD. Future interventions may need to focus on certain therapeutic categories and polypharmacy.