Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Biotechnol Rep (Amst) ; 37: e00787, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36818378

RESUMO

Selenium nanoparticles (SeNPs) have antimicrobial and antifungal activity. SeNPs using Se resistant bacteria is a low cost and eco-friendly technology. Fungal contamination of wood during drying is one of the main causes of economic losses in the wood industry. The bacterium Delftia sp. 5 resistance to Se and its ability to produce SeNPs able to inhibit the growth of the wood brown-rotting fungus Oligoporus pelliculosus was analyzed. The strain showed an optimal SeNPs production when selenite concentration was 160 mg L -1. The SeNPs were spherical with an average size 192.33 ± 8.6 nm and a zeta potential of -41.4 ± 1.3 nm. The SeNPs produced by Delftia sp. 5 (33.6 ± 0.1 mg L -1 Se) inhibited the growth of O. pelliculosus in agar plates and in Nothofagus pumilio (Lenga) wood samples. Delftia sp. 5 SeNPs could be used for embedding lenga wood prior to drying for preventing the growth of the deteriorating fungi O. pelliculosus.

2.
Photochem Photobiol Sci ; 22(3): 503-512, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36327035

RESUMO

Magnetic Fe-Cu nanocomposites with high adsorption capacity and photocatalytic properties were prepared via the precursor method using soluble substances isolated from urban biowaste (BBS) as carbon sources and different temperatures of the pyrolysis treatment (400, 600, and 800 °C). BBS is used as complexing agent for the Fe3+ and Cu2+ ions in the precursors. The as-prepared magnetic materials were tested in As(III) removal processes from water. Dark experiments performed with the materials obtained at 400 and 600 °C showed excellent adsorption capacities achieving a significant uptake of 911 and 840 mg g-1 for As(III), respectively. Experiments conducted under steady-state irradiation showed a reduction of 50-71% in As(III) levels evidencing the meaningful photocatalytic capacity of Fe-Cu nanocomposites. The best photocatalytic performance was obtained for the nanocomposite synthesized at the highest pyrolysis temperature, in line with the reported trend of HO· radicals production. Transient absorption spectroscopy experiments revealed the occurrence of an alternative oxidation pathway involving the valence band holes and yielded relevant kinetic information related to the early stages of the As(III) photooxidation. The higher absorption of the electron-hole pairs observed for the samples treated at lower temperature means that controlling the pyrolysis temperature during the synthesis of the Fe-Cu nanocomposites allows tuning the photocatalyst activity for oxidation of substrates via valence band holes, or via HO· radicals.

3.
Nanomaterials (Basel) ; 9(10)2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31561528

RESUMO

The use of iron-based nanomaterials for environmental remediation processes has recently received considerable attention. Here, we employed core-shell magnetite-humic acids nanoparticles as a heterogeneous photosensitizer and iron source in photo-Fenton reaction for the degradation of the psychiatric drug carbamazepine (CBZ). CBZ showed low photodegradation rates in the presence of the magnetic nanoparticles, whereas the addition of hydrogen peroxide at pH = 3 to the system drastically increased the abatement of the contaminant. The measured Fe2+ and Fe3+ profiles point to the generation of Fe3+ at the surface of the nanoparticles, indicating a heterogeneous oxidation of the contaminant mediated by hydroxyl radicals. Products with a higher transformation degree were observed in the photo-Fenton procedure and support the attack of the HO• radical on the CBZ molecule. Promising results encourage the use of the nanoparticles as efficient iron sources with enhanced magnet-sensitive properties, suitable for applications in photo-Fenton treatments for the purification of wastewater.

4.
Intern Emerg Med ; 9(7): 759-65, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24352793

RESUMO

The aim of the study was to determine the influence of the previous use of digoxin on the hospital mortality and complications of patients admitted because of acute coronary syndrome (ACS). We analyzed the data of patients included in the ARIAM-Andalucia Registry, which involves 49 hospitals in Andalucia, Spain, from 2007 to 2012. Patients on digoxin treatment prior to their admission because of ACS constituted the digoxin group (DG), and were compared with the group of patients not on digoxin. Logistic regression and propensity score matching were used to analyze the differences. We included 20,331 patients, of whom 244 (1.2%) were on digoxin. DG patients were older (73.1 vs 63.7 years old), more often women, and had more diabetes, hypertension, previous myocardial infarction, heart failure, stroke, atrial fibrillation, peripheral vascular disease, obstructive pulmonary disease or kidney disease. On univariate analysis, DG patients had significantly higher hospital mortality (13.5 vs 5.3% P < 0.001), and more cardiogenic shock, but less ventricular fibrillation, and no differences in atrioventricular block, stroke or reinfarction. After the multivariate analysis, DG had no significant influence on hospital prognosis [odds ratio (OR) 1.21, 95% confidence interval 0.79-1.86]. The analysis of a propensity-matched cohort of 464 patients (232 DG and 232 NoDG) did not find differences in hospital mortality (13.4 vs 13.4%) nor other complications. In our cohort of ACS patients, the previous treatment with digoxin was not associated with an increase in dysrhythmic complications nor was an independent predictor of mortality during hospitalization.


Assuntos
Síndrome Coronariana Aguda , Antiarrítmicos/uso terapêutico , Digoxina/uso terapêutico , Síndrome Coronariana Aguda/complicações , Síndrome Coronariana Aguda/mortalidade , Idoso , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Espanha , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA