The toxicity of copper to crucian carp (Carassius carassius) in soft water

Crucian carp (Carassius carassius) were exposed to a Cu rich medium (pH 6.6, conductivity 25 microS/cm, 2.91 mg Ca(2+)/l, approximately 300 microg Cu(2+)/l). Untreated department water (pH 6.6, conductivity 25 microS/cm, 2.91 mg Ca(2+)/l) acted as control. Mortality in crucian carp was first observed after 13 days of exposure to the Cu rich medium. There were, however, significant changes in haematocrit, plasma chloride, plasma sodium and water content in muscle in fish exposed to the Cu rich medium after two days. After 14 days of exposure to copper, haematocrit increased to 52+/-2% (control: between 37 and 40%), plasma chloride decreased to 45+/-5 mmol/l (control: 99-106 mmol/l), plasma sodium decreased to 81+/-6 mmol/l (control: 116-137 mmol/l), and water content in muscle increased to 83.0+/-0.3% (control: 78.7-79.9%). No apparent changes in blood ethanol, and minor changes in plasma lactate were observed in copper exposed fish. Analyses of the gills revealed an increasing concentration of copper on the gills from fish exposed to Cu rich water. After 14 days, the concentration of copper accumulated in the gill was 12.8+/-4.1 microg Cu/g wet weight (control: 0.91-1.19 microg Cu/g wet weight). A reduction of the respiratory area in fish exposed to copper was observed, in terms of both lamellar and filamental fusion. The normoxic O(2) uptake did not change, but the critical oxygen tension was elevated to 6.12+/-1.04 mg O(2)/l after a 6 day exposure to copper (control: 1.03+/-0.05 mg O(2)/l). This study shows that crucian carp has a higher tolerance to copper compared to other freshwater fish species. Our results suggest that this tolerance is based on the ability of crucian carp to avoid becoming hypoxic as well as an extreme tolerance to severe loss of plasma ions.     

Effects of two chelating agents (EDTA and DTPA) on the autochthonous vegetation of a soil polluted with Cu, Zn and Cd

Chelating agents are thought to be useful for the remediation of metal-polluted soils with adequate organic matter, but the effects of these substances on the plants or seed bank of plant communities that occur in the soils are relatively unknown. In this work, the effects of two chelating substances (EDTA and DTPA) on a wet grassland plant community affected by the presence of the abandoned copper mine "Fernandito" (Garganta de los Montes, Madrid) were compared. A microcosm bioassay (6 months) was designed using the soil's top layer containing the grassland's seed bank. This soil showed a high Cu pollution level, significant contents of Zn and Cd (1120, 190, and 15 ppm, respectively), a pH of 5 and an OM content of 6.2%. The soil was subjected to three different treatments: a) untreated soil (control), b) the addition of 1 g/kg EDTA, or of c) 1 g/kg DTPA. The results presented here are those related to the plant cover, species richness, aboveground and subterranean biomass and chemical composition of the most abundant plants. Neither EDTA nor DTPA caused intense negative effects on the plants rather they significantly increased the amount of copper accumulated in aboveground parts and roots. In particular, Agrostis castellana and Corrigiola telephiifolia extracted high amounts of copper when grown in the soil with added EDTA, although they showed some nutritional imbalances (lower P contents). In contrast, lower metal concentrations were detected in plants grown in the DTPA amended soil.     

Use of dendrochronological method in Pinus halepensis to estimate the soil erosion in the South East of Madrid (Spain)

The rate of soil erosion in pine forests (Pinus halepensis) located in the Southeast of Madrid has been estimated using dendrochronological analysis based on the change in ring-growth pattern from concentric to eccentric when the root is exposed. Using 49 roots spread across five inclined areas, it has been found that the length and direction of the hillsides, as well as their vegetation cover affect the rate of erosion, while the slope itself does not. The erosion rates found for the different areas studied vary between 3.5 and 8.8 mm year(-1), that is between 40 and 101 t ha(-1) year(-1) respectively. These values are between 2 and 3 times greater than those predicted by USLE, for which this equation underestimates soil loss for Central Spain's Mediterranean conditions. Nonetheless, both methods (using dendrochronology to determine actual soil loss and theoretical prediction with USLE) are able to establish the same significant differences among the areas studied, allowing for the comparative estimate of the severity of the area's erosion problem.     

Yttrium incorporation in Cr2AlC: On the metastable phase formation and decomposition of (Cr,Y)2AlC MAX phase thin films

Herein we report on the synthesis of a metastable (Cr,Y)₂AlC MAX phase solid solution by co-sputtering from a composite Cr–Al–C and elemental Y target, at room temperature, followed by annealing. However, direct high-temperature synthesis resulted in multiphase films, as evidenced by X-ray diffraction analyses, room-temperature depositions, followed by annealing to 760°C led to the formation of phase pure (Cr,Y)₂AlC by diffusion. Higher annealing temperatures caused a decomposition of the metastable phase into Cr₂AlC, Y₅Al₃, and Cr-carbides. In contrast to pure Cr₂AlC, the Y-containing phase crystallizes directly in the MAX phase structure instead of first forming a disordered solid solution. Furthermore, the crystallization temperature was shown to be Y-content dependent and was increased by ∼200°C for 5 at.% Y compared to Cr₂AlC. Calculations predicting the metastable phase formation of (Cr,Y)₂AlC and its decomposition are in excellent agreement with the experimental findings.     

Structural performance of alkali/acid-ultrasound modified Agave fibers during the melt mixing process with polyvinyl alcohol

This study aims to investigate changes in the structural properties of alkali/acid-ultrasound modified Agave fibers and their performance immersed on a polyvinyl alcohol (PVA) matrix with plasticizer during melt mixing processing. Structural analysis revealed that ultrasound enhances the effectiveness of the conventional alkaline/acid treatments to modify fibers since the simultaneous treatment increased the partial removal of lignocellulosic components, water molecules, and amorphous regions which improved their processability on a PVA matrix. Specific energy consumption values indicated that during melt mixing the modified fibers required more energy to expose the chains of cellulose fraction to function as an interaction site for PVA chains. Once the mixture was homogenized, the fiber-matrix interactions promoted high viscosity, friction, and mechanical stress in the chamber. Therefore, the modified fibers restricted the interaction between plasticizer and PVA in the obtained films, resulting in a highly structured, and reinforced network, increasing the storage modulus as dynamic mechanical analysis indicated. These findings highlight a feasible way to valorize Agave fibers and allow the understanding of the matrix-fiber interactions during melt mixing processing, useful to predict the structural and mechanical properties of the films.     

Production of Cocoa Butter Microcapsules Using an Electrospray Process

An experimental approach to the production of cocoa butter microcapsules containing an aqueous solution or an oil‐in‐water emulsion via electrified coaxial jets is presented here. Recently, a new method to generate nano‐micrometric coaxial jets has been reported. These coaxial jets are generated by electrohydrodynamic forces with diameters that range from hundreds of nanometers to tens of microns. The controlled break‐up of the jets gives rise to an aerosol of compound droplets in which an outer liquid coats an inner one. This technique has turned out to be an effective method to encapsulate aqueous‐based food ingredients such as flavors, aromas, enzymes, salts, minerals, and vitamins in the micrometric range with relatively high monodispersity and controllable geometrical parameters of the capsules such as thickness of the shell or number of inner cores in the capsules.     

Brazilian red propolis: unreported substances, antioxidant and antimicrobial activities

BACKGROUND: Chloroform, ethyl acetate and methanol extracts of a sample of red propolis from the state of Alagoas (northeast Brazil) were analyzed by gas chromatography–mass spectrometry and high‐performance liquid chromatography–diode array detection–electrospray ionization‐mass spectrometry. Antimicrobial and antioxidant activities were also obtained. RESULTS: The propolis sample contained low content of narigenin‐8‐C‐hexoside, this being the first report of a C‐glycoside in propolis. The main constituent found was characterized as 3,4,2′,3′‐tetrahydroxychalcone. Other important constituents were the chalcone isoliquiritigenin, the isoflavans (3S)‐vestitol, (3S)‐7‐O‐methylvestitol, the pterocarpan medicarpin, the phenylpropenes trans‐anethol, methyl eugenol, elimicin, methoxyeugenol and cis‐asarone, and the triterpenic alcohols lupeol and α‐ and β‐ amyrins. The methanol extract exhibited high antioxidant activities by 2,2‐diphenyl‐1‐picrylhydrazyl and β‐carotene/linoleic acid assay methods, and antimicrobial activity toward Gram‐positive and Gram‐negative bacteria. CONCLUSION: Structures are suggested for new substances never before seen in any kind of propolis. This is the first report of 3,4,2′,3′‐tetrahydroxychalcone and a flavone C‐glycoside in a propolis sample. Copyright © 2011 Society of Chemical Industry     

Anthocyanin composition and extractability in berry skin and wine of Vitis vinifera L. cv. Aglianico

BACKGROUND: The present article reports the anthocyanin content in the berry skin and wine of the Italian red grape cultivar Aglianico (clone VCR11 grafted onto 1103 Paulsen), one of the most ancient vines and famous for its deep‐red colour. Anthocyanins were extracted from frozen berry skin in an acidified methanol solution. The extraction mixtures, monitored for 120 h, were analysed by high‐performance liquid chromatography. RESULTS: The extraction from berry skin of delphinidin, petunidin and malvidin appeared to be a time‐independent process, whereas the concentration of peonidin increased linearly with time. Peonidin‐O‐acetyl‐glucoside was transferred from skin more slowly than petunidin‐O‐acetyl‐glucoside and malvidin‐O‐acetyl‐glucoside. The anthocyanin composition of the resulting wine showed that the total anthocyanin content was about one‐tenth of the corresponding berry skin content. The ratio acetyl/coumaroyl anthocyanins in the wine was sharply higher than the value in berry skin (0.85 and 0.10, respectively), indicating an enrichment of acetyl derivatives in the wine. CONCLUSION: Levels of single anthocyanins in wine were not always correlated with those detected in grapes, as they were affected by winemaking. The high values of some anthocyanins in Aglianico wine could ameliorate its quality, increasing the chromatic properties, aging stability and product acceptance. Copyright © 2011 Society of Chemical Industry