RESUMO

The present work evaluates ozone driven processes (O3, O3/UVC, O3/TiO2/UVA) in the NETmix mili-photoreactor, as a cost-effective alternative for the removal of volatile organic compounds (VOCs) from air streams, using n-decane as a model pollutant. The network of channels and chambers of the mili-photoreactor was coated with a TiO2-P25 thin film, resulting in a catalyst coated surface per reactor volume of 990 m2 m-3. Ozone and n-decane streams were fed to alternate chambers of the mili-photoreactor, promoting a good contact between O3/n-decane/catalyst. Initially, direct reaction between n-decane and ozone (ozonation) was assessed for different O3/n-decane (O3/dec) feed molar ratios and total feed flow rates. Under the best conditions, ozonation process achieved total n-decane conversion (below the limit of detection), yielding a reaction rate (rdec) of 6.8 µmol min-1 or 6.7 mmol m-3reactor s-1. However, the low reactivity of ozone with the degradation by-products resulted in a quite poor mineralization (~10%). For the O3/UVC system, an increase on relative humidity from 7 to 40% slight improved the n-decane oxidation rate, mainly associated with the generation of HO from the reaction of active oxygen radicals (O) and water molecules. A strong synergistic effect was observed when coupling TiO2/UVA photocatalysis with ozonation (O3/TiO2/UVA), enhancing substantially the mineralization of n-decane molecules up to 100% under O3/dec feed molar ratio of 15, photonic flux of 2.67 ±â€¯0.03 J s-1 and a residence time of 2.0 s. Different reaction intermediates were detected for O3, TiO2/UVA and O3/TiO2/UVA oxidative systems, indicating the participation of different oxidant species (O3, HO, O, etc.).

RESUMO

Genetic diversity allows identification of potential intraspecific genotypes in the genus Passiflora. The objective of this study was to examine the morphological and genetic diversity of auxin-induced Passiflora mucronata. The experiments were arranged in a complete randomized block design, with a 9 x 2 factorial arrangement (nine genotypes x presence and absence of auxin, indole-3-butyric acid (IBA)), with four replicates of 16 cuttings. The rooting and vegetative growth responses were variable. Genotype 5 was more responsive in the absence of IBA and genotypes 3, 8 and 9 were more responsive in the presence of IBA. Auxin increased rooting rate and percentage, reducing the average time of root protrusion in eight days. IBA also contributed to increase photosynthesis and dry root and shoot mass in 55.55 and 44.44% of the genotypes, respectively. The highest relative contribution to phenotypic diversity in the absence of auxin was rate (38.75%) and percentage (20.27%) of rooting, whereas in the presence of auxin was stomatal conductance (23.19%) and root dry mass (20.91%). Similarity was found for phenotypic and molecular divergence in the presence of IBA, in which genotypes 1 and 6; genotypes 5, 8 and 9; and genotype 3 were clustered in distinct groups.

Assuntos

Variação Biológica da População/genética , Passiflora/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Gases/metabolismo , Marcadores Genéticos/genética , Variação Genética , Indóis/farmacologia , Passiflora/efeitos dos fármacos , Passiflora/genética , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Estômatos de Plantas/efeitos dos fármacos , Transpiração Vegetal/fisiologia , Plântula/genética

RESUMO

Background. Leprosy reactions are acute inflammatory episodes that occur mainly in the multibacillary forms of the disease. The reactions are classified as type 1 (reverse reaction) or type 2 (erythema nodosum leprosum). Leprosy-associated oxidative stress has been widely demonstrated. Several recent studies have shown uric acid (UA) to have antioxidative effects under pathologic conditions. The objective of this study was to assess serum levels of UA in patients with leprosy reactions, with the aim of monitoring their levels before and after treatment, compared with levels in leprosy patients without reactions. Methods. The study included patients aged 18-69 years assisted at a leprosy treatment reference center in the Central Region of Brazil. Patients who were pregnant; were using immunosuppressant drugs or immunobiologicals; or had an autoimmune disease, human immunodeficiency virus infection, acquired immune deficiency syndrome, or tuberculosis were excluded. Upon recruitment, all individuals were clinically assessed for skin lesions and neural or systemic impairment. Some patients had already completed treatment for leprosy, while others were still undergoing treatment or had initiated treatment after being admitted. The treatment of the reactional episode was started only after the initial evaluation. Laboratory assessments were performed upon admission (baseline) and at approximately 30 and 60 days (time points 1 and 2, respectively). Results. A total of 123 leprosy patients were recruited between June 2012 and June 2015; among them, 56, 42, and 25 presented with type 1, type 2, and no reactions, respectively. Serum UA levels were significantly reduced in patients with type 2 leprosy reactions compared with patients in the control group and remained lower in the two subsequent assessments, after initiation of anti-reaction treatments, with similar values to those recorded before the treatment. Discussion. The decreased serum UA levels in patients with type 2 leprosy reactions might be due to the consumption of UA to neutralize the enhanced production of oxygen- and nitrogen-reactive species that occurs during type 2 reactions. The maintenance of the reduced levels in the follow-up assessments may indicate persistence of oxidative stress in the initial post-treatment stages, despite improved clinical conditions. The results of this study suggest that serum UA may play an antioxidative role during type 2 leprosy reactions.