RESUMO
In this work, the performance of a photo-Fenton process-based textile effluent treatment was investigated using both solar and artificial light sources. A full 3(3) factorial experimental design was applied for the optimisation with respect to three parameters: initial pH, amounts of Fe(2+) (0.01-0.09 g L(-1)) and H(2)O(2) (1-7 g L(-1)). The photo-Fenton process response was evaluated on the basis of chemical oxygen demand (COD) removal and decolourisation. The optimum conditions of the photo-Fenton process were attained at concentration values of 0.05 g Fe(2+) L(-1) and 6.0 g H(2)O(2) L(-1) and pH 3, for both solar and artificial light sources. The effects of initial pH, and Fe(2+) and H(2)O(2) concentrations were evaluated. From the monitoring of TOC, COD, turbidity and decolourisation over time, the progress of the mineralisation of dyes was analysed, forming nitrate, ammonia nitrogen and nitrite. Low amounts of residual peroxide and iron, which were below the limit allowed by Brazilian environmental legislation, were attained after 360 min of irradiation time for both artificial and solar sources. An operational cost of US$ 6.85 per m(3) of treated effluent was estimated using solar irradiation.
Assuntos
Resíduos Industriais , Fotoquímica/métodos , Têxteis , Eliminação de Resíduos Líquidos/métodos , Análise da Demanda Biológica de Oxigênio , Peróxido de Hidrogênio/química , Ferro/químicaRESUMO
The main objective of this study was to evaluate the metal content in water and sediment from the Toledo municipal lake, as well as the concentration levels of heavy metals in muscle and liver of four fish species. A digestion procedure was performed in all fish samples. Metal analysis was performed by using the Synchrotron Radiation X-ray Fluorescence technique. The accuracy and validity of the measurements were determined by analysis of certified reference materials. The highest Cr, Cu and Se concentration levels above the maximum tolerance limit according to the Brazilian norms in fish tissue could be associated with the metal uptake and accumulation due to the direct contact with contaminated water and sediment.
Assuntos
Peixes/fisiologia , Água Doce/análise , Sedimentos Geológicos/análise , Metais/análise , Poluentes Químicos da Água/análise , Animais , Brasil , Fígado/química , Músculos/química , Espectrometria por Raios XRESUMO
This study is focused on the analysis of an accumulation of inorganic elements in muscles, liver and gonad of seven fish species from São Francisco River located in the Paraná state of Brazil. Concentrations of the elements were determined using the SR-TXRF technique. In the muscles of fish species, negative length dependent relationships were observed for chromium and zinc ion absorption. The obtained results showed that accumulated Cr ions values are above the limits defined in the Brazilian legislative norm on food.
Assuntos
Peixes/metabolismo , Gônadas/metabolismo , Fígado/metabolismo , Músculos/metabolismo , Oligoelementos/metabolismo , Animais , Brasil , Especificidade da EspécieRESUMO
The effect of Cr(6+) on Allium cepa root length was studied using both clean and polluted river waters. Seven series of Cr(6+)-doped polluted and non-polluted river waters were used to grow onions. Chromium concentration (Cr(6+)) of 4.2 mg L(-1)(EC(50) value), doped in clean river water caused a 50% reduction of root length, while in organically polluted samples similar root growth inhibition occurred at 12.0 mg Cr(6+) L(-1). The results suggested that there was a dislocation to higher values in toxic chromium concentration in polluted river water due to the eutrophization level of river water.
Assuntos
Cromo/toxicidade , Cebolas/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Rios/química , Poluição da Água , Cromo/farmacologia , Relação Dose-Resposta a Droga , Cebolas/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Testes de Toxicidade/métodosRESUMO
INTRODUCTION: Chronic daily headache (CDH) is a chronic painful clinical condition that is frequently found in neurological practice. Diagnosis is clinical and the therapeutic approach is complex. Its mechanism of production is still not altogether clear, but a genetic component is acknowledged as a predisposing factor. Numerous areas are involved in the generation of primary headaches, including the periaqueductal grey matter (PAGM), which plays a role as a neuromodulator both in headaches and in other chronic painful conditions. AIMS: In order to evaluate possible biochemical changes in patients with CDH, magnetic resonance imaging was used to study the spectra produced in the PAGM. SUBJECTS AND METHODS: The spectra in the PAGM were studied in 17 patients with CDH. These were compared with the average spectra in 17 healthy subjects by means of differential spectroscopy. RESULTS: Subjects with CDH show a reduction of over 70% in the level of the metabolite N-acetyl-aspartyl-glutamate (NAAG) in the PAGM. NAAG is a peptide involved in antinociceptive activity. CONCLUSIONS: The reduction of NAAG in the PAGM suggests altered neuromodulation of the antinociceptive systems in subjects with CDH. Whether CDH is the cause or the consequence has still to be determined.
Assuntos
Transtornos da Cefaleia/fisiopatologia , Dor/fisiopatologia , Substância Cinzenta Periaquedutal/metabolismo , Adulto , Dipeptídeos/metabolismo , Feminino , Transtornos da Cefaleia/metabolismo , Transtornos da Cefaleia/patologia , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Fármacos Neuroprotetores/metabolismo , Substância Cinzenta Periaquedutal/anatomia & histologia , Substância Cinzenta Periaquedutal/patologiaAssuntos
Humanos , Masculino , Pessoa de Meia-Idade , Diarreia , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Vipoma , Pâncreas , Técnicas HistológicasRESUMO
In order to evaluate the survival of patients with myasthenia gravis (MG) after thymectomy (T), 100 patients with MG in which T had been performed between 1967 and 1995 were studied. Patients were divided into different groups for their analysis: patients with thymoma (TI), 22 cases; and patients without thymoma (NTI), 78 cases. In addition those patients belonging to the latter group were further separated according to the date of their surgery into two other subgroups: patients operated before 1980 (A80), 43 cases; and after 1980 (D80), 35 cases; trying to evaluate the prognostic implications of the therapeutical advances achieved over the last 15 years. The population studied was composed mainly of women (78%) but with a slight predominance of men in TI. The mean age was 29.47 years (range 10-70) for the entire population, with a tendency toward older ages in TI (mean 46 years, range 23-70). The mean follow-up period was 4.3 years (range 0.08-23.2) without significant differences between TI and NTI. The results showed that the overall mortality rate was 16/100 (16%) [Fig. 1], with nine of those deaths corresponding to TI (9/22, 40.91%) and only the remaining seven to NTI (7/78, 8.97%). These differences in mortality rate between TI and NTI were statistically significant in all the specific times of follow-up analyzed up to 10 years after surgery (p < 0.05) [Fig. 2]. Notoriously, all deaths in NTI occurred in the A80 subgroup giving a p value < 0.001 when compared with D80 [Fig. 3]. In terms of morbidity, 55/100 (55%) reached complete clinical remission (CCR) defined by the complete absence of symptoms related to MG: 8/22 (36.36%) in TI and 47/78 (60.25%) in NTI [Fig. 4]. Most interestingly the differences were statistically significant (p < 0.01) when the rates of CCR in A80 and D80 were compared for all the times assessed [Fig. 5-6-7-8]. It can be concluded that the best results in survival in MG after T are obtained in patients without thymoma and also that the benefits of the rational use of modern therapeutic modalities, including surgery and immunosuppression with drugs, can offer those patients high possibilities of leading completely normal lives.