Search

The demands of learning in the twenty-first century require being skilled in the use and comprehension of multiple documents. Some individual factors such as the metacognitive skill of theory of mind (ToM) are related to this ability. This study investigated the relationship between university students' ability to comprehend multiple documents, measured through an argumentative essay task, and their ToM. The participants were 84 undergraduates. We assessed their ToM (using the strange stories task) and their mental state talk (using a think-aloud protocol during the reading of multiple documents—MSTR—and through the content of their subsequent written essays—MSTW). The relation between students' ToM and their MSTW was mediated through MSTR. In addition, students' ToM was significantly associated with the quality of the essays, through MSTR, and the relation between MSTR and the argumentative quality was mediated through MSTW. MSTW was the only significant predictor of the quality of the essays. The involvement of ToM in multiple-document comprehension suggests, from an educational perspective, the possibility to support multiple-document comprehension by scaffolding mental state talk. [ABSTRACT FROM AUTHOR]

The residue of chestnut processing generates a large amount of waste material, a resource not adequately exploited. The antioxidant and antitumoral properties of cold and hot water extracts from discarded pericarp of four chestnut Sardinian accessions and one marron variety were studied. The antioxidant capacity of the extracts was determined by spectrophotometric and electrochemical tests. The 1,1-diphenyl-2-pic-rylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) results were highly correlated with each other; likewise, a good correlation was found between Ferric Reducing Antioxidant Power (FRAP) and cyclic voltammetry (CV) values, both based on the direct transfer of electrons. The antiproliferative effect on normal cells (fibroblasts), and on colon (RKO and SW48) and breast (MCF7) cancer cells was evaluated. Additionally, this paper marks the first application of chestnut extracts to investigate their effects on melanoma (B16F10) cells. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test demonstrated that temperature and different extraction times significantly influenced the growth of cells, both normal and tumor. The fibroblast growth was significantly inhibited by moderate doses of cold extracts, while the GI50 values calculated for hot extracts were high, regardless of the accession or cultivar. An even more marked inhibitory action of the cold extracts was observed both on the growth of RKO and SW48 cells and on B16F10 melanoma cells. Otherwise, an extract concentration, both cold and hot, of no less than 243 µg mL−1 is required to achieve a 50% inhibition of MCF7 cell growth. [ABSTRACT FROM AUTHOR]

Simple Summary: In this paper the phenolic composition of Syrah and Chardonnay grape pomaces was studied to assess their antioxidant and prooxidant properties, and their effect on melanoma cancer cells. The phenolic composition of Syrah and Chardonnay grape pomaces was studied to assess their antioxidant and prooxidant properties. Polyphenols were extracted by a "green" hydroalcoholic solvent (ethanol/water 1:1 v/v), and a detailed chemical and electrochemical characterization of the phenolic compounds was performed. The antioxidant and prooxidant capacity of the pomace was first studied by cyclic voltammetry (CV) and other reference analytical assays, then with biological tests on B16F10 metastatic melanoma cancer cells. Electrochemical data showed that, when a +0.5 V potential was applied, a low to moderate antioxidant capacity was observed. MTT test showed an increasing viability of melanoma cells, after treatments at low concentration (up to 100 μg/mL) and for a short time (6 h), but when cells were treated with higher doses of extract (≥250 μg/mL for 12/24 h), their viability decreased from 25 to 50% vs. control, depending on treatment time, dose, and extract origin. A stronger prooxidant activity resulted when 250 μg/mL of extract was combined with non-toxic doses of H2O2; this activity was correlated with the presence of copper in the extracts. This study shows the potential of winemaking by-products and suggests the opportunity to exploit them for the production of cosmeceuticals, or for combined therapies with approved anticancer drugs. [ABSTRACT FROM AUTHOR]