Polyurethane-acrylate based films as humidity sensors

Fluorescence spectroscopy, together with a conventional gravimetric method, were employed to study the mechanism and kinetics of water diffusion in UV-cured polyurethane-acrylate based adhesive films doped with organic fluorescent sensors. The diffusion of water through the films followed Fick's law during almost the whole mass sorption curve. Whilst the fluorescence data showed that boundary conditions are more complex and Fickian behaviour is only observed after different periods, depending on the molar volume of the fluorescent probe and the adhesive composition. The influence of hydrophilic monomers is discussed. Good correlation between diffusion coefficients by both methods is obtained in the range where water uptake is diffusion controlled.

The fluorescence of the studied probes or labels in these films shows high sensitivity to humidity, good long-term stability and fast response time. Therefore, it appears that these doped films can be used as efficient humidity sensors.     

Acidity and DAG Content of Olive Oils Recently Produced on the Island of Mallorca

In this study, the quality characteristics, i.e., the acidity and acylglycerols, of currently produced Mallorcan oil was analyzed by titration and gas-chromatographic technique, respectively, in approximately 400 samples of monovarietal olive oil made from three genetic varieties (Arbequina, Empeltre, and Picual) on the island of Mallorca during the 2003/2004 and 2005/2006 seasons, and the differences in the compositions were discussed. Composition analysis showed that free fatty acids (FFAs) and DAGs were produced mainly by hydrolysis of triacylglycerols (TAGs). Fruit storage tests revealed that hydrolysis occurred during storage of olive fruits. The DAG content was higher in oil with higher acidity, but the maximal DAG content was only about 10 with 30% acidity, and the primary isomer found in Mallorcan oil was 1,3-DAG. However, the chiral-chromatographic study on the ratio of sn-1,2-DAG to the sum of sn-1,2-DAG and sn-2,3-DAG in a slightly hydrolyzed oil sample indicated that Empeltre and Picual fruits possess an sn-3-enantioselective lipase that leads to accumulation of sn-1,2-DAG. In currently produced Mallorcan oil, significant isomerization appears to occur and hydrolysis of the resulting 1,3-DAGs seems to lessen DAG accumulation.     

Resveratrol as an anti-inflammatory and anti-aging agent: mechanisms and clinical implications

Resveratrol is a phytoalexin polyphenolic compound found in various plants, including grapes, berries, and peanuts. Multiple lines of compelling evidence indicate its beneficial effects on neurological, hepatic, and cardiovascular systems. Also one of the most striking biological activities of resveratrol soundly investigated during the late years has been its cancer-chemopreventive potential. In fact, recently it has been demonstrated that this stilbene blocks the multistep process of carcinogenesis at various stages: tumor initiation, promotion, and progression. One of the possible mechanisms for its biological activities involves downregulation of the inflammatory response through inhibition of synthesis and release of pro-inflammatory mediators, modification of eicosanoid synthesis, inhibition of activated immune cells, or inhibiting such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) via its inhibitory effects on nuclear factor (kappa)B (NF-(kappa)B) or the activator protein-1 (AP-1). More recent data provide interesting insights into the effect of this compound on the lifespan of yeast and flies, implicating the potential of resveratrol as an anti-aging agent in treating age-related human diseases. It is worthy to note that the phenolic compound possesses a low bioavailability and rapid clearance from the plasma. As the positive effects of resveratrol on inflammatory response regulation may comprise relevant clinical implications, the purpose of this article is to review its strong anti-inflammatory activity and the plausible mechanisms of these effects. Also, this review is intended to provide the reader an up-date of the bioavailability and pharmacokinetics of resveratrol and its impact on lifespan.     

Interaction of porosity with a planar solid/liquid interface

In this article, an investigation of the interaction between gas porosity and a planar solid/liquid (SL) interface is reported. A two-dimensional numerical model able to accurately track sharp SL interfaces during solidification of pure metals and alloys is proposed. The finite-difference method and a rectangular undeformed grid are used for computation. The SL interface is described through the points of intersection with the grid lines. Its motion is determined by the thermal and solute gradients at each particular point. Changes of the interface temperature because of capillarity or solute redistribution as well as any perturbation of the thermal and solute field produced by the presence of non-metallic inclusions can be computed. To validate the model, the dynamics of the interaction between a gas pore and a solidification front in metal alloys was observed using a state of the art X-ray transmission microscope (XTM). The experiments included observation of the distortion of the SL interface near a pore, real-time measurements of the growth rate, and the change in shape of the porosity during interaction with the SL interface in pure Al and Al-0.25 wt pct Au alloy. In addition, porosity-induced solute segregation patterns surrounding a pore were also quantified.     

Chemopreventive effect of dietary curcumin on inflammation‐induced colorectal carcinogenesis in mice

Scope: Curcumin is a polyphenol with a variety of pharmacologic effects. We evaluate the effect of dietary curcumin on the severity of repeated colitis‐associated colorectal cancer. Methods and results: Six‐week‐old C57BL/6 mice were randomized into two dietary groups: standard diet and curcumin at 0.6% diet. The mice were exposed to 15 cycles of 0.7% dextran sodium sulphate for 1 week followed by distilled water for 10 days. After curcumin diet, the disease activity index presented a statistical reduction in the last cycles, macroscopic tumors were not seen and the microscopic study showed minor neoplasic lesions with respect to standard diet‐group. β‐Catenin translocation to the cytoplasm and/or nucleus was observed in the tumor tissue, but this translocation and its intensity were significantly minor in the curcumin diet‐DSS animals. Cytokines as tumor necrosis factor‐α and IFN‐γ were significantly diminished in DSS‐animals fed with curcumin. Conversely, non‐modification of p53 expression was observed and cyclo‐oxygenase‐2 and inducible nitric oxide synthase were significantly reduced in the curcumin diet‐DSS group. Conclusion: We demonstrate the protective/preventive effect of curcumin in the progression of colorectal cancer associated to colitis, which was correlated with a lowered immunoreactivity of ß‐catenin, a non‐modification of p53 expression, a reduction of proinflammatory cytokine levels and a decrease of inflammatory protein overexpression.     

New Insights in the Use of Trehalose and Modified Starches for the Encapsulation of Orange Essential Oil

During the encapsulation of aromas by spray-drying, some volatile components may be lost; consequently, the sensory profile could be modified in the final product. Therefore, the selection of the carrier matrix for the encapsulation is crucial to obtain high aroma retention and long shelf-life stability, reduce aroma oxidation and increase physical stability of the powder. With the aim of studying the use of trehalose for the encapsulation of orange essential oil, emulsions were prepared containing mixtures of trehalose–maltodextrin (TMD) and sucrose–maltodextrin (SMD). Two modified starches were used as emulsifiers. The emulsions were spray-dried and stored at 25 and 37 °C. The aroma retention was evaluated using head space–solid phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC-MS) and by sensory evaluation. In addition, some physical properties of orange essential oil powders, such as water sorption and glass transition temperature (T _g), were determined. The sensory profiles obtained for TMD and SMD were different: TMD formulations retained mainly limonene, while SMD retained mostly α-pinene and myrcene. The modified starches (Capsul and Hi Cap) used as emulsifiers also affected the retention of certain volatiles. Therefore, the selection of components in the carrier matrix is relevant to the retention of aromas in orange oil powders. Regarding the physical properties, TMD formulations presented better characteristics in comparison to SMD, particularly due to the higher T _g values. The high aroma retention levels and the good physical characteristics are promising results in relation to the inclusion of the developed formulations in dehydrated citric juices.     

Study of Spray System Applications of Edible Coating Suspensions Based on Hydrocolloids Containing Cellulose Nanofibers on Grape Surface (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.)

An edible coating is a useful technology to preserve fruit quality by covering them with a protective layer which improves the appearance and provides a semipermeable barrier for gases and water vapor transfer, allowing extension of their shelf life. In this study, edible coatings based on hydroxypropyl methyl cellulose, k-carrageenan, glycerol, and cellulose nanofibers were formulated. The operational conditions of the spray system were studied to obtain a coating with optimal adhesion on grape (Vitis vinifera L.) surface. Furthermore, the physico-chemical properties of grapes covered with edible coatings were evaluated during refrigerated storage. A full factorial 2³ experimental design was applied, where liquid suspension flow (1–5 L h^?1), air pressure (50–200 kPa), and height of impact (0.3–0.5 m) were evaluated as independent variables, whereas the percentage of coating and thickness of coating was the response variables. Both mechanical and physico-chemical properties were evaluated during 41 days in both coated and uncoated grapes as shelf life criteria. Throughout the storage time, noticeable changes in pH and total soluble solids were not found in grapes covered with edible coatings and they showed the highest stability for the evaluated mechanical properties. Moreover, coated grapes showed final weight loss and water vapor permeability values of approximately 30 and 34% lower, respectively, than uncoated grapes, suggesting a shelf life extension.     

Regulation of food advertising on television for the prevention of childhood obesity

Obesity is a serious global epidemic and the prevention strategies implemented have been insufficient. Numerous environmental factors have been associated with risk of obesity and their full consideration in prevention policies is important. The connection between food advertising on television and childhood obesity has been demonstrated. The large number of advertisements for unhealthy foods targeted at children through television and its possible impact on health has led some countries to legislate on this matter. However, a conceptual framework of reference enabling legislation must be internationally defined in order to achieve a real impact in preventing childhood obesity. This paper reviews scientific evidence on the relationship between food advertising and childhood obesity as a basis for developing public policies to regulate food marketing on television.