No abstract

Martelo-Vidal M.J., Vázquez M. (2014): Evaluation of ultraviolet, visible, and near infrared spectroscopy for the analysis of wine compounds. Czech J. Food Sci., 32: 37-47.Spectroscopy of UV-VIS-NIR combined with chemometric analyses was used as a non-destructive technique to build models for the quantitative characterisation of the main compounds of wine. The work in mixtures can give insight into how interferences affect the performance of calibrations in wines. Ethanol, glycerol, glucose, tartaric acid, malic acid, lactic acid, and acetic acid were evaluated as pure compounds and in mixtures. Different pre-treatments for the spectra and modelling strategies such as partial least squares (PLS) regression or Principal Component Regression (PCR) were evaluated. All pure compounds studied showed a good relationship between spectra and concentrations. However, interferences were observed in the mixtures and only good models for ethanol, tartaric acid, and malic acid were obtained. The best model was obtained in the NIR region for ethanol and in the UV region for tartaric acid and malic acid. The results indicate that NIR spectroscopy could be used as an alternative to conventional chemical methods for ethanol determination and UV spectroscopy for the determination of tartaric acid and malic acid.

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Patients with prednisone-resistant nephrotic syndrome and biopsy-proven focal segmental glomerulosclerosis were treated with intravenous methylprednisone. After the first 2 weeks of therapy, the average urine protein excretion decreased from 247 to 96 mg/m²/h (p < 0.04). Two of the 7 patients have had long-term, nearly complete remissions. The other patients relapsed. One relapsing patient was retreated with methylprednisolone and is now in remission. Four relapsing patients were treated with alkylating agents, in combination with methylprednisolone. All of these patients entered complete or partial remissions. Methylprednisolone causes a significant decrease in the proteinuria of children with focal segmental glomerulosclerosis. In addition, although the follow-up period is relatively short, it would appear that methylprednisolone, often in conjunction with an alkylating agent, has significantly improved the clinical status of these patients.

Sugar cane bagasse was hydrolyzed under different concentrations of hydrochloric acid (2-6%), reaction times (0-300 min), and temperatures (100-128 degrees C). Sugars obtained (xylose, glucose, arabinose, and glucose) and degradation products (furfural and acetic acid) were determined. Based on the Saeman model and the two-fraction model, kinetic parameters for predicting these compounds in the hydrolysates were developed. The influence of temperature was studied using the Arrhenius equation. The optimal conditions selected were 128 degrees C, 2% HCl, and 51.1 min. Using these conditions, 22.6 g xylose/L, 3.31 g arabinose/L, 3.77 g glucose/L, 3.59 g acetic acid/L, and 1.54 g furfural/L were obtained.