Structural Investigation and Functional Properties of MgxNi1−xFe2O4 Ferrites

The preparation, structural, microstructural, dielectric, and low temperature magnetic properties of Mg_xNi_1?xFe₂O₄ (x = 0, 0.17, 0.34, 0.50, 0.66, 0.83, 1) ferrites synthesized by using a self‐combustion sol–gel method is presented. Good insulating properties were found for all the compositions at high frequencies (kHz and MHz range), which might drive the present ceramics as interesting for RF/microwaves applications. By increasing the Mg²⁺ concentration, the total resistivity strongly increases (from ~10⁶ Ωm for the Ni ferrite to 10⁹ Ωm for the Mg ferrite), corresponding to conductivities in the range 10^?9–10^?6 S/m at f = 1 Hz. Typical ferrimagnetic character with a small coercivity and saturation magnetization in the range (30–50) Am²/kg, which slightly decreases with increasing the Mg content, were found. On the basis of the combined results from the infrared spectroscopy and XRD analysis, it was shown that the magnetic properties depend on the Mg²⁺ ions distribution on the octahedral and tetrahedral sites and the experimental saturation magnetization allowed to compute the cation distribution for the Mg_xNi_1?xFe₂O₄ ferrites.     

Morphology and Mechanical Properties of iPP/Silica Composites Modified with (Styrene-b-ethylene-co-butylene-b-styrene) Grafted with Maleic Anhydride

The effects of different silica grades and elastomer content on interfacial properties, morphology and mechanical properties of polypropylene/silica 96/4 composites modified with added 5, 10, 15, and 20% of poly(styrene-b-ethylene-co-butylene-b-styrene) grafted with maleic anhydride (SEBS-g-MA) were investigated. The iPP/silica/SEBS-g-MA composites were designed by adding four silica fillers differing in size (nano- vs. micro-) and in surface properties (hydrophilic vs. hydrophobic) and SEBS-g-MA that was used as a proven effective impact modifier and compatibilizer simultaneously. The morphology of every composite was a spectrum of several morphologies rather than one exclusive morphology. Good concordance between observed and predicted morphology indicated that the morphology of a particular composite was controlled primarily by interfacial properties. Tensile and impact properties were influenced primarily by competitive effects of a stiff filler and tough SEBS-g-MA elastomer. Increased impact strength and strain at break caused by adding SEBS-g-MA indicated a significant overcoming of the elastomeric toughening effect in relation to the filler’s stiffening effect.     

Resveratrol Modulation of Apoptosis and Cell Cycle Response to Cisplatin in Head and Neck Cancer Cell Lines

In head and neck cancers, the effectiveness of cisplatin (CisPt) treatment is limited by its toxicity, especially when higher doses are necessary, and the possible occurrence of cisplatin resistance. This study evaluated the effects of resveratrol (RSV) on the expression of different genes involved in the response of human tumor cells (FaDu, PE/CA-PJ49) to cisplatin therapy. Our results revealed that RSV induced apoptosis amplification in both FaDu and PE/CA-PJ49 cells and modulated the expression of specific genes differently than in normal HaCaT cells. In FaDu cells, combined CisPt + RSV treatment induced an increase in apoptosis, which was associated with an increase in c-MYC and TP53 and a decrease in BCL-2 expression. While CisPt + RSV treatment induced apoptosis in PE/CA-PJ49 cells by inhibition of BCL-2 associated with high levels of MDM-2 and subsequently led to inhibition of TP53 gene expression. Decreased c-MYC expression in PE/CA-PJ49 treated with CisPt + RSV was accompanied by cell cycle blockage in G0/G1 phase. In conclusion, RSV influences tumor cell response to CisPt by inducing apoptosis and modulating gene expression. In addition, in normal HaCaT cells, RSV was able to reduce the harmful effects of CisPt.     

A motivational interviewing and common factors approach to change in working with alcohol use and abuse in college students.

The authors describe an approach for intervening with college students who present for self-referred or mandated treatment for alcohol or other drug issues. The authors offer a conceptual framework for working with such clients that is influenced by the evidence-based motivational interviewing literature and the evidence-based common factors approach to psychotherapy in general. Implications for practice are elaborated on and exemplified through a case study that includes motivational interviewing's guiding principles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wheat dough rheology and bread quality effected by Lactobacillus brevis preferment,dry sourdough and lactic acid addition

The influence of chemical and biological acidification on dough rheological properties and bread quality has been investigated. Two different flour types were used. Dough was chemically acidified with lactic acid. Two types of biologically acidified dough were prepared: dough with dry sourdough and with a Lactobacillus brevis preferment. Wheat dough rheological properties were investigated using the Farinograph, Extensograph and Amylograph. The baking response was also determined using standard baking tests. Addition of acidifiers resulted in firmer doughs with less stability, decreased extensibility and decreased gelatinisation maximum. The biological acidifiers increased the bread specific volume. Lactic acid addition had no influence on bread specific volume. In general, biological and chemical acidification decreased bread hardness. The addition of dry sourdough significantly decreased the lightness and increased the yellowness and redness of the bread crumb. The crust chroma, hue angle and brownness index were significantly changed by addition of acidifiers.     

Poly(vinylpyrrolidone) – A Versatile Polymer for Biomedical and Beyond Medical Applications

The high versatility of poly(vinylpyrrolidone) (PVP) can be explained by its diverse properties including its solubility in water and in a broad range of liquid media, high chemical and thermal resistance, and unique wetting, binding, and film-forming properties. Thanks to biocompatibility, absence of toxicity and high capacity to form interpolymer complexes, PVP is widely used for designing materials for different applications, such as biomaterials for medical and nonmedical uses. This review summarizes a vast diversity of applicative examples showing the tremendous opportunities for future research and developments of PVP based biomaterials.     

Improving TiO2 activity in photo-production of hydrogen from sugar industry wastewaters

A series of TiO₂ photocatalysts dispersed on SiO₂, modified with metals (Mn, Cr, V) or non-metals (N or S) or covered with Au nanoparticles were prepared by incipient wetness impregnation, impregnation with urea or thiourea, and deposition-precipitation, respectively. The photocatalysts where characterized by chemical analysis, X-ray diffraction (XRD), diffuse reflectance UV-Vis spectroscopy (DR-UV-Vis) and Fourier transform infrared spectroscopy (FTIR). The photocatalytic activity was checked in the photogeneration of hydrogen from sugar solutions. The nature of the modifying species was found to influence the photoactivity and N and S led to more effective catalysts than metals. This behavior was attributed to the fact the N and S are less effective in forming recombination centers compared with the metals.