Enzymatic de-glycosylation of rutin improves its antioxidant and antiproliferative activities

Bioavailability and biological properties of flavonoid glycosides can be improved after the enzymatic hydrolysis of specific glycosyl groups. In this study, we evaluate the antioxidant and antiproliferative potential of rutin after enzymatic hydrolysis performed by α-l-rhamnosidases (hesperidinase from Penicillium sp. and naringinase from Penicillium decumbens) previously heated at 70 °C for 30 min to inactivate the undesirable β-d-glucosidase activity. The highest in vitro antioxidant activity determined by DPPH radical scavenging was achieved with rutin hydrolyzed by hesperidinase. Rutin was predominantly bioconverted into quercetin-3-glucoside. There was no statistical difference between xanthine oxidase inhibition by rutin before and after hydrolysis. However, in vitro inhibitory activity against ten human tumor cell lines showed that hydrolyzed rutin exerted a more potent antiproliferative effect than quercetin and rutin on various cancer cell lines, specially glioma, and ovarian and breast adenocarcinomas. These results indicate that quercetin-3-glucoside could be a promising functional derivative obtained by rutin hydrolysis.     

The effectiveness of ozone and acidulant treatments in extending the refrigerated shelf life of fresh-cut potatoes

Abstract: The objective of the study was to determine the effectiveness of acidulant dip treatments (with or without aqueous ozone) to reduce enzymatic browning and to extend the shelf life of fresh‐cut potato slices during refrigerated storage (4 °C) for 28 d. Potato slices subjected to aqueous ozone (2 ppm) had significantly (P≤ 0.05) higher L‐values and lower a‐values, but ozone did not appear to have any effect on aerobic plate counts (APCs) or polyphenol oxidase (PPO) activity. NatureSeal (NS) and sodium acid sulfate (SAS) were the most effective acidulant treatments in reducing browning (significantly [P≤ 0.05] higher L‐values, lower a‐values, and browning index values) regardless of ozone treatment. NS and SAS also had lower PPO activity compared to other treatments on days 0 and 28, and significantly (P≤ 0.05) lower APCs (≤2.00 log CFU/g) over refrigerated storage. Therefore, the SAS treatment was comparable to NS, a commercially available product, and showed promise as an effective antibrowning dip to reduce browning and spoilage in fresh‐cut potato products. Practical Application: A 1% SAS dip treatment which included 1% citric and 1% ascorbic acid was found to be an effective antibrowning dip for fresh‐cut potatoes along with NatureSeal®'s PS‐10, compared to other treatments. They were both effective in maintaining low microbial counts over refrigerated storage. Additionally, aqueous ozone washes (2 ppm) showed significant benefits to reduce browning; however, ozone did not affect microbial counts or PPO enzyme activity. Therefore, the SAS treatment could have potential use in the fruit and vegetable industry to reduce browning and spoilage in fresh‐cut potato products.     

3D Printing of Customized Li‐Ion Batteries with Thick Electrodes

The growing demand for rechargeable lithium‐ion batteries (LIBs) with higher capacity in customized geometries underscores the need for new battery materials, architectures, and assembly strategies. Here, the design, fabrication, and electrochemical performance of fully 3D printed LIBs composed of thick semisolid electrodes that exhibit high areal capacity are reported. Specifically, semisolid cathode and anode inks, as well as UV curable packaging and separator inks for direct writing of LIBs in arbitrary geometries are created. These fully 3D printed and packaged LIBs, which are encased between two glassy carbon current collectors, deliver an areal capacity of 4.45 mAh cm^?2 at a current density of 0.14 mA cm^?2, which is equivalent to 17.3 Ah L^?1. The ability to produce high‐performance LIBs in customized form factors opens new avenues for integrating batteries directly within 3D printed objects.     

Acts of will?

Discusses the articles contained in the present volume addressing the issue of will and the frequent disconnect between what people intend to do and what they actually do. The authors in the series suggest that people perceive themselves to have more control over everyday behavior than they actually do. The authors present a conceptual and empirical framework for understanding the causes of behavior for the times when it is recognized that "will" has broken down and people are unable to act as they desire. According to the authors, the source of behavioral control comes not from active awareness but from subtle cues in the environment and from thought processes and information not readily accessible to consciousness. The theory and data presented in these articles represent recent fundamental breakthroughs in the understanding of motivations, free will and behavioral control. The premise of the 4 articles is this: There are mental activations of which we are unaware and environmental cues to which we are not consciously attending that have a profound effect on our behavior and that help explain the complex puzzle of human motivation and actions that are seemingly inexplicable, even to the individual performing the actions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

L'attachment à l'age scolaire et le développement des troubles de comportement.

The purpose of this longitudinal study was to examine the association between the mother–child attachment relationship and behavioural problems among a test group of 120 Francophone Canadian children from mixed social and economic backgrounds. The Strange Situation protocol was used to measure attachment styles when the children were between the ages of 5 and 7 yrs. Each child's behavioural difficulties were assessed by his or her educator or teacher during 3 developmental periods: 3–5 yrs, 5–7 yrs, and 7–9 yrs. Results show that disorganized insecure attachment is associated with an increased risk of developing exteriorized and interiorized behavioural troubles between the ages of 5 and 7. The authors also observed exteriorized behavioural problems among children with anxious-ambivalent attachment, especially in the 3–5 age group. Avoidant children, usually assessed positively, received exteriorization scores during the 5–7 period which were significantly below those of securely attached children. Avoidant boys also exhibited more interiorized symptoms during this time-frame. Analyses of the persistence of behavioural problems also showed increased risk among disorganized and ambivalent children with secure or avoidant attachment styles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimization of electrically conductive films: Poly(3-methylthiophene) or polypyrrole in Kapton

A method to generate conductive films composed of small amounts of conductive polymer absorbed into the surface of polyimide films has been optimized. Both pyrrole (PY) and 3-methylthiophene (3MT) were evaluated as precursors for the conductive phase. Predictive models were empirically derived for each precursor to describe the effects of polymerization variables on the conductivity of the films. The variables studied were found to be highly synergistic. An optimum set of conditions was found for each conductive polymer that produces the highest conductivity. Using p-3MT as the conductive phase, films with conductivity as high as 5.7 Ω⁻¹ cm⁻¹ can be produced, an improvement of four orders of magnitude over previously reported results with Kapton as a base polymer. The highest conductivity achieved using p-PY as the conductive phase was 0.041 Ω⁻¹ cm⁻¹, still a two order of magnitude improvement over previously reported results. Mean mechanical properties of the 3MT-treated films were not significantly lower than that for untreated Kapton. The conductivities of p-3MT/Kapton films tested over time under ambient temperature in air persist fairly well for 300 days. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 821–834, 1997     

Simultaneous reconstruction of evolutionary history and epidemiological dynamics from viral sequences with the birth–death SIR model

The evolution of RNA viruses, such as human immunodeficiency virus (HIV), hepatitis C virus and influenza virus, occurs so rapidly that the viruses'' genomes contain information on past ecological dynamics. Hence, we develop a phylodynamic method that enables the joint estimation of epidemiological parameters and phylogenetic history. Based on a compartmental susceptible–infected–removed (SIR) model, this method provides separate information on incidence and prevalence of infections. Detailed information on the interaction of host population dynamics and evolutionary history can inform decisions on how to contain or entirely avoid disease outbreaks. We apply our birth–death SIR method to two viral datasets. First, five HIV type 1 clusters sampled in the UK between 1999 and 2003 are analysed. The estimated basic reproduction ratios range from 1.9 to 3.2 among the clusters. All clusters show a decline in the growth rate of the local epidemic in the middle or end of the 1990s. The analysis of a hepatitis C virus genotype 2c dataset shows that the local epidemic in the Córdoban city Cruz del Eje originated around 1906 (median), coinciding with an immigration wave from Europe to central Argentina that dates from 1880 to 1920. The estimated time of epidemic peak is around 1970.     

Electron Impact Mass Spectra With Supercritical Fluid Chromatography/Mass Spectrometry

ABSTRACT

An SFC/MS system has been constructed through additions and appropriate modifications to a GC/MS instrument. Supercritical fluid conditions were effected by transport of liquid carbon dioxide mobile phase through a micro pump to the injector and then into a fused silica capillary column. Two approaches to a successful coupling of the resultant effluent to the GC/MS system in order to yield EI mass spectra have been demonstrated. In one configuration, an open-split GC/MS interface was used to eliminate excess mobile phase. Inside the heated interface was a frit restrictor connected to a deactivated, uncoated fused silica capillary column (also heated) which functioned as a transfer line into the ion source. An alternate configuration omitted the open-split interface and located the frit restrictor inside the ion source. A specially fabricated stainless steel rod, heated by the ion source heater, had a conical opening into which the restrictor tip was positioned and also heated. In both configurations, a turbomolecular pump was used in the ion source. In the above systems, EI mass spectra were satisfactorily produced without ion-molecule contributions or carbon dioxide clusters. The resulting spectra can thus be searched against a conventional mass spectral library for the identification of compounds separated by supercritical fluid chromatography.     

A potential biodegradable lubricant from castor biodiesel esters

Worldwide, 12 million tonnes per year of lubricants are disposed of in the environment through leakages, exhausted gas, incorrect disposal, water–oil emulsions and so on. Some are resistant to biodegradation, representing an environmental threat. One solution to modify this situation is the replacement of mineral oils by biodegradable synthetic lubricants. Esters, whose chemical structures are similar to natural triglycerides, are excellent substitutes for mineral oils. Castor oil contains around 90% ricinoleic acid, and as a result, castor oil has a higher viscosity and a lower viscosity index, compared with other vegetable oils. This work was based on the production of biodegradable lubricant base fluids from castor biodiesel esters, using various chemical catalysts to yield products with interesting properties, such as high viscosity index and good oxidation stability, compared with mineral oils. This route to lubricants is safer, more economical and more efficient. Copyright © 2012 John Wiley & Sons, Ltd.