Determinarea capacitătii antioxidante totale a unor vinuri roşii prin metode electrometrice şi spectrofotometrice

Phenolic compounds from various food matrices can be investigated with different analytical techniques such as spectrophotometric, cromatographic or electrochemic methods. Cupric Reducing Antioxidant Capacity method (CUPRAC) is a convenient assay for determining total antioxidant capacity in food substrates. In this work, electrochemical and spectrophotometrical approaches were used to estimate the total antioxidant capacity by means of an alternative of the CUPRAC assay, as the concentrations of the participating species ([Cu(Nc)2]2+ and [Cu(Nc)2]1+) can be evaluated by electrochemical and spectrophotometrical methods. The electrometric–CUPRAC methods have been applied to measure total antioxidant capacity of different local wines and validated against the spectrophotometric CUPRAC assay. The electrochemical methods proved to be easy, fast and with low detection limits. A good correlation for the total antioxidant capacity determined by CUPRAC spectrofotometric and electrometric method versus total phenol content (determined by Folin-Ciocalteu Method) was recorded, wich highlights that wines antioxidant activity results mainly from their phenolics content

Hydroxymethylation of technical lignins from South American sources with potential use in phenolic resins

This work investigates the valorization of sodium lignosulfonate, kraft, and organosolv lignins from South America. A detailed characterization of the lignins and their chemical modification by hydroxymethylation through its reaction with formaldehyde were performed. The characterization included measurements of moisture, ash, carbohydrate contents, elemental and thermogravimetric analysis, and functional groups, molar mass distributions by Fourier transform infrared spectroscopy, and size exclusion chromatography, respectively. Also, reactive aromatic hydrogens ( HAr) were quantified by the measurement of phenolic hydroxyl groups (P-OH) content by UV–Vis spectroscopy. The different initial formaldehyde/lignin weight ratios (0.07, 1.47), temperatures (40, 50, and 70 C), and pHs (9, 11); and the following of hydroxymethylation reactions by UV–Vis spectroscopy were investigated. All lignins resulted attractive for the use as replacement of phenol in phenolic resins, but sodium lignosulfonate was the most appropriate due to its water solubility. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47712.Fil: Taverna, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Felissia, Fernando Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Estenoz, Diana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Nicolau, Verónica Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional; Argentin

The Synergic Effect of AT(N) Profiles and Depression on the Risk of Conversion to Dementia in Patients with Mild Cognitive Impairment

Few studies have addressed the impact of the association between Alzheimer’s disease (AD) biomarkers and NPSs in the conversion to dementia in patients with mild cognitive impairment (MCI), and no studies have been conducted on the interaction effect of these two risk factors. AT(N) profiles were created using AD-core biomarkers quantified in cerebrospinal fluid (CSF) (normal, brain amyloidosis, suspected non-Alzheimer pathology (SNAP) and prodromal AD). NPSs were assessed using the Neuropsychiatric Inventory Questionnaire (NPI-Q). A total of 500 individuals with MCI were followed-up yearly in a memory unit. Cox regression analysis was used to determine risk of conversion, considering additive and multiplicative interactions between AT(N) profile and NPSs on the conversion to dementia. A total of 224 participants (44.8%) converted to dementia during the 2-year follow-up study. Pathologic AT(N) groups (brain amyloidosis, prodromal AD and SNAP) and the presence of depression and apathy were associated with a higher risk of conversion to dementia. The additive combination of the AT(N) profile with depression exacerbates the risk of conversion to dementia. A synergic effect of prodromal AD profile with depressive symptoms is evidenced, identifying the most exposed individuals to conversion among MCI patients