LC–MS analysis of the cis isomers of chlorogenic acids

The behaviour of cis isomers of selected mono- and di-acyl chlorogenic acids produced by UV-irradiation has been investigated by LC–MSⁿ. cis Isomers fragment identically to the more common trans isomers. cis-5-Acyl chlorogenic acids are more hydrophobic and elute later than their mono- or di-trans counterparts whereas the reverse is true for cis-3-acyl and cis-4-acyl chlorogenic acids. The cis isomers of 1,3-dicaffeoylquinic acid, the only 1-acyl chlorogenic acid investigated, are also more hydrophobic than the di-trans isomer. Coffee leaves had a proportionately greater content of cis isomers relative to trans isomers compared with coffee beans suggesting that UV-irradiation in vivo may also cause geometric isomerisation.     

Effect of irradiation on the antioxidative and antigenotoxic activities of a green tea leaf and stem extract

Green tea (Camellia sinensis) leaf and stem extract, a major byproduct of the green tea industry, was investigated for its antioxidative and antigenotoxic activities after 20 kGy of irradiation. In vitro antioxidative activities, including 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, hydrogen peroxide inhibition, tyrosinase inhibition activities, and the reducing power were tested. Green tea leaf extract (GTLE) had higher antioxidative activities than the green tea stem extract (GTSE). Irradiation of 20 kGy to GTLE showed a decreasing tendency in DPPH radical, hydrogen peroxide‐scavenging activities, and reducing power, while that to GTSE showed an increasing tendency of the antioxidative activities. Tyrosinase inhibition activity showed no difference on irradiation, in GTLE and GTSE. Overall, irradiation had positive influences on the antioxidative activity in the GTSE more than in the GTLE. Antigenotoxic effect of the green tea extracts on an oxidative DNA damage in human leucocytes by a DNA comet assay also indicated a protective effect of GTLE. The irradiated GTLE began to decrease the DNA damage significantly at 10 μg mL^?1, which showed a higher inhibition activity than the non‐irradiated GTLE. The non‐irradiated and irradiated GTSE showed similar inhibition trends and they were comparable with that of the GTLE. Results suggest that the extract of GTSE, a major byproduct of the green tea industry, can be considered as a cost‐effective functional ingredient for industrial applications. Furthermore, irradiation of the GTSE may have beneficial effects on its functional activity.     

Mindful Attention Awareness Scale (MAAS): Psychometric properties of the French translation and exploration of its relations with emotion regulation strategies.

Over the past few years, several questionnaires have been developed to measure mindfulness. The Mindful Attention Awareness Scale (MAAS) was created to specifically capture attention and awareness in daily life (Brown & Ryan, 2003). In this article, we present a French adaptation of the MAAS. In the 1st study, we explored the psychometric properties of this adaptation. In the 2nd study, we investigated its relation to cognitive emotion regulation and depressive symptomatology using path analysis. As in the original version of the MAAS, the French adaptation has a strong 1-factor structure. Moreover, there was a negative relationship between the MAAS and the severity of depressive symptoms, both directly and indirectly. The indirect pathway was mediated by the nonadaptive cognitive emotion regulation strategy of self-blame and the adaptive cognitive emotion regulation strategy of positive reappraisal. In conclusion, this questionnaire represents a valid mindfulness measure for French-speaking clinicians and researchers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Flood Control in the Cuiabá River Basin, Brazil, with Multipurpose Reservoir Operation

Periodic flooding in the Cuiabá River Basin (CRB), which is located in the upper Pantanal region, in central-western Brazil, led to the construction of the Manso multipurpose reservoir and power plant. This study evaluates the influence of the Manso reservoir on the attenuation of downstream flooding specifically in the metropolitan area of Cuiabá, which is the capital city of the state of Mato Grosso. The flood routing provided by the Manso reservoir was simulated by means of the Puls modified method (level-pool routing method), and the translation of the flood wave during floodplain passage was calculated with the CLiv hydrodynamic model for critical hydrological events. It is demonstrated that the reservoir reduces the frequency of flood risk to downstream communities for return periods between 50 and 100 years. Despite the flood attenuation, other measures should be undertaken in addition to the reservoir operation to mitigate the impacts of flooding in a comprehensive and appropriate way. In particular, measures related to floodplain land use planning and management are important to ensure that the safety of the population does not exclusively depend on the upstream reservoir.     

Evaluation of the conditions of carotenoids production in a synthetic medium by Sporidiobolus salmonicolor (CBS 2636) in a bioreactor

This work studied the cultivation conditions for the production of carotenoids by Sporidiobolus salmonicolor (CBS 2636) in a bioreactor. A Plackett–Burman design was used for the screening of the most important factors, followed by a complete second order design, to maximise the concentration of total carotenoids. The maximum concentration of 3425.9 μg L^?1 of total carotenoids was obtained in a medium containing 80 g L^?1 glucose, 15 g L^?1 peptone and 5 g L^?1 malt extract, with an aeration rate 1.5 vvm, 180 r.p.m., 25 °C and an initial pH of 4.0. Fermentation kinetics showed that the maximum concentration of total carotenoids was reached after 90 h of fermentation. Carotenoid bio‐production was partially associated with cell growth. The specific carotenoid production (Y_P/X) was 238 μg carotenoids/g cells, whereas Y_P/S (substrate to product yield) was 41.3 μg g^?1. The specific growth rate (μ_x) was 0.045 h^?1. The highest cell and total carotenoid productivity were 0.19 g L^?1 h^?1 and 56.9 μg L^?1 h^?1, respectively.     

Electrochemical and morphologic studies of nickel incorporation on graphite electrodes modified with polytyramine

Electrodes modified with electropolymerized films have received considerable attention in the development of catalysts and sensors, and their use is rapidly increasing. This work reports modification of the surface of graphite electrodes by electrochemical polymerization of tyramine. These modified electrodes were used to nickel incorporation and hydrogen evolution. Tyramine electrooxidation, in acid and basic media, yielded polymeric films onto graphite surface. In ferrocyanide/ferricyanide solution, the electrodes modified in acid medium showed higher electron transfer efficiency. Impedance studies indicated higher charge transfer resistance to electrodes modified with Ptyr prepared in basic pH. Scanning electron microscopy showed that the formed films present different morphology for the several pH values studied. Interferometry and scanning electron microscopy analysis showed higher coverage to films formed in acid medium. Polymers produced in more alkaline medium present growth self-limited. Nickel was incorporated in the films through immersion of the modified electrodes in solution of potassium hexafluoronickelate, followed of electrochemical reduction of the metal. The electrocatalytic activity of the modified electrodes with nickel incorporated was tested for hydrogen evolution reaction. The amount of nickel mass incorporated as well as the current density of hydrogen evolution reaction was higher in electrodes modified with polytyramine produced in acid medium.     

Conducting Flame-Sprayed Al Coatings on Textile Fabrics

Electrical conductive and flexible flame-sprayed Al coatings using powder and wire as raw material were successfully deposited onto diverse textile fabrics. The influences of the raw materials, spraying parameters, and fabric materials on the electrical conductivity and microstructure of the metal-fabric composites were investigated. A first series of experiments showed that a coating quantity higher than 20 mg/cm² is necessary for a very good surface conductivity. After the optimization of the spraying parameters, such as a reduced standoff distance and the use of a cooling setup, a high surface conductivity (∼500 S _A) was obtained, which is attributed to a better melting of the spray particles. The improvement in conductivity enables a reduction of the coating quantity, and therefore, the flexibility of the fabric materials is better conserved. This study showed that optimized electrically conductive composites onto flexible fabrics can be produced, without any preliminary thermal or chemical fabric specifications.     

Viscoelastic properties of wood across the grain measured under water-saturated conditions up to 135 °C: evidence of thermal degradation

In this paper, the viscoelastic properties of wood under water-saturated conditions are investigated from 10 to 135 °C using the WAVE^T apparatus. Experiments were performed via harmonic tests at two frequencies (0.1 and 1 Hz) for several hours. Four species of wood were tested in the radial and tangential material directions: oak (Quercus sessiliflora), beech (Fagus sylvatica), spruce (Picea abies) and fir (Abies pectinata). When the treatment is applied for several hours, a reduction of the wood rigidity is significant from temperature values as low as 80–90 °C and increases rapidly with the temperature level. The storage modulus of oak wood is divided by a factor two after 3 h of exposure at 135 °C. This marked reduction in rigidity is attributed to the hydrolysis of hemicelluloses. The softening temperature of wood is also noticeably affected by hygro-thermal treatment. After three short successive treatments up to 135 °C, the softening temperature of oak shifted from 79 °C to 103 °C, at a frequency of 1 Hz. This reduction in mobility of wood polymers is consistent with the condensation of lignins observed by many authors at this temperature level. In the same conditions, fir exhibited a softening temperature decrease of about 4 °C. In any case, the internal friction clearly rises.