RESUMO
With the rapid development of nanotechnology, the environmental behavior and ecological effect of nanoparticles (NPs) are receiving more and more attention. As an important environmental component, metal oxide NPs occur widely in nature, such as in water bodies, air, soils, and sediments. They have a large surface area and high surface activity, allowing them to control and affect the speciation, migration, transformation, and bioavailability of some contaminants and nutrients in the environment. The nano-size is a unique property of nanoparticles. The size of particles regulates and determines the structure and physicochemical properties of nano-oxides, which greatly affects interfacial reactions with the relevant elements and environmental geochemical behaviors. The effects of NPs size on the environmental geochemical behaviors, such as adsorption, (reductive) dissolution, (catalytic) oxidation, aggregation and transport, are briefly summarized, and the mechanism of the size effect is discussed. Finally, hot spots for future research of metal oxide nanoparticles related to size effects in the environment are proposed.
RESUMO
Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. The goal of the present study was to quantify the association between use of nonsteroidal anti-inflammatory drugs (NSAIDs) and risk of AF incidence. MEDLINE and EMBASE were searched for studies that reported risk of AF associated with nonaspirin NSAID use. Combined relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated using the random-effects model. Stratified meta-analyses were used to discern which patients were at the highest risk of AF due to NSAID use. Five studies were identified that met the inclusion criteria, 3 of which additionally reported specifically on the association between selective NSAIDs and risk of AF. Overall, NSAID use was associated with a 12% increased risk for AF incidence (RR 1.12, 95% CI 1.06 to 1.18). The association was found to be apparent among new users (RR 1.53, 95% CI 1.37 to 1.70). The increased risk of AF might be explained by the occurrence of chronic heart failure and kidney disease. In addition, use of selective NSAIDs was still related to an increased risk of AF (RR 1.24, 95% CI 1.18 to 1.30). Sensitivity analyses found results to be robust. In conclusion, use of nonaspirin NSAIDs was associated with an increased risk of incident AF. The association was found to be apparent for new users, with a 53% increase in risk. These findings suggest that AF needs to be added to the cardiovascular risks to be considered when prescribing NSAIDs.
Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Fibrilação Atrial/epidemiologia , Medição de Risco , Fibrilação Atrial/etiologia , Saúde Global , Humanos , Incidência , Fatores de RiscoRESUMO
The sorption and desorption characteristics of four kinds of organic phosphorus with different molecular structures (glycerophosphate (GP), glucose-6-phosphate (G6P), adenosine triphosphate (ATP), and myo-inositol hexakisphosphate (IHP)) on three kinds of aluminum (oxyhydr)oxides (amorphous Al(OH)3, boehmite, and alpha-Al2O3) were studied. The underlying mechanisms were also illustrated. Results showed that the maximum sorption amounts of OP onto Al (oxyhydr)oxides, on a per gram dry weight basis, decreased as following: amorphous Al(OH)3 > boehmite > alpha-Al2O3. This mainly related to the mineral crystallinity and surface heterogeneity. With the exception of sorption of IHP on amorphous Al (OH)3, the maximum sorption density decreased with increasing molecular weight (MW) of OP, following the order: GP > G6P > ATP > IHP. However, the sorption amount of IHP on amorphous Al (OH)3 was much higher than those of other OP, due to the transformation of surface complexes of IHP to surface precipitation and thus enhancing the sorption. The sorption kinetics results showed that sorption of OP underwent the first onset rapid sorption, i. e. a certain amount of sorption occurred within an onset extremely short period, and a following long and slow sorption process. Amorphous Al (OH)3 had the greatest onset rapid sorption density, and the onset rapid sorption density of OP on Al (oxyhydr) oxides decreased with increasing MW. Desorption capacities of OP by KCl and citrate solutions related to the surface affinity between OP and boehmite. Initial desorption percentages by KCl decreased in the order: G6P (10.53%) > GP(6.91%) > ATP (3.06%) > IHP (0.8%). The maximum desorption percentages of OP by citrate were 4-5 times greater than those by KCl. During resorption process of P by KCl, the maximum desorption rate achieved after a fast desorption in a few hours, followed by diffusion-resorption during which the desorption percentage gradually decreased. Specially, both diffusion-resorption and surface precipitation promoted the resorption of IHP on mineral surface. Conclusively, the strong specific sorption of OP occurs on the surface of Al (oxyhydr) oxides, and molecular structure and size of OP as well as the crystallinity and crystal structure of minerals are the key factors affecting the interfacial reactions and environmental behaviors of OP.