Evaluation of Portuguese and Spanish Quercus pyrenaica and Castanea sativa species used in cooperage as natural source of phenolic compounds

A study on the phenolic composition of Portuguese and Spanish Castanea sativa and Quercus pyrenaica woods used in cooperage has been carried out with the aim of looking for an extra value for the wood residues generated in cooperage industries. Results showed that both species are an important source of valuable phenolic compounds, although differences in the phenolic content were found. Chestnut samples showed the highest concentration of total phenolic compounds, being especially rich in vescalagin, gallic acid, vanillic aldehyde and syringaldehyde. The geographical origin was another parameter to take into account. Portuguese chestnut samples showed higher amounts of phenolic compounds than the Spanish samples, with vescalagin, gallic acid, vanillic acid and syringaldehyde being the most important features. As a consequence, the residues generated in the cooperage industry from chestnut and Q. pyrenaica heartwood seem to be an important source of valuable phenolic compounds, particularly those from Portuguese chestnuts.     

An open framework for translating portable applications into operating system‐specific wireless sensor networks applications

Wireless sensor networks (WSNs) are distributed systems integrated by tiny devices, called sensor nodes, with capabilities to monitor the environment and forward their measurements to a special node, the sink, where the results can be collected and further processed. The trend in WSN is moving towards heterogeneous networks that will contain different sensor nodes running different instances of custom operating systems. Given the growing demand of new hardware platforms and operating systems specifically designed for sensor nodes, the applications programming for sensor nodes is becoming a challenging process that needs to be alleviated. Currently, application programming for sensor nodes is a complex, ad hoc, and error‐prone process where the portability among different platforms has been sacrificed. In this paper, we propose an open framework aimed to achieve application portability in heterogeneous sensor networks. Our approach provides the programming abstractions needed to support the application development process for sensor nodes. We have implemented an open framework that provides a set of tools on top of the most popular WSN operating systems to translate portable applications to the native operating system in an automatic, simple, and transparent way for developers. We have also evaluated the applications thus generated in terms of productivity and overhead, by comparing their footprint to those originally developed in each specific operating system. The results show that the overhead is minimal—4% in the worst case—and in some cases, it was even possible to reduce the footprint by using code optimizations. Copyright © 2012 John Wiley & Sons, Ltd.     

Optimisation of pressurised liquid extraction for the determination of monosaccharides and polyalcohols in woods used in wine aging

BACKGROUND: The carbohydrate profile of woods used to age wines and spirits is largely unstudied in spite of its possible influence on the quality of aged beverages. This experiment evaluated the feasibility of employing pressurised liquid extraction to isolate monosaccharides and polyalcohols from woods used in aging, yielding a reliable analytical extraction method for characterising these compounds. Various solvents were tested and the extraction procedure was optimised by a three‐level factorial experimental design based on two main factors: extraction temperature and extraction time. The total extraction yield of target compounds was taken as response variable, and model parameters were estimated by multiple linear regression. RESULTS: Methanol was best at extracting the target compounds and hence was selected as solvent. Temperature was the most important factor in the extraction process, and the optimal extraction conditions were 90 °C for 15 min. CONCLUSION: Pressurised liquid extraction proved to be a highly suitable and powerful technique for extracting the monosaccharides and polyalcohols from wood samples. Analysis of the carbohydrate profile of the woods revealed differences among samples of different species and types of wood. Copyright © 2009 Society of Chemical Industry     

Long-term evaluation of a sequential batch reactor (SBR) treating dairy wastewater for carbon removal.

Many dairy industries have been using SBR wastewater treatment plants because they allow optimal working condition to be reached. However, to take advantage of SBR capabilities, strong process automation is needed. The aim of this work is to study the factors that influence SBR performance to improve modelling and control. To better understand the whole process we studied the kinetic modelling, the carbon removal mechanism and the relation between reactor performance, aerobic heterotrophic activity and bacterial population dynamics (by terminal restriction fragment length polymorphisms of 16S rDNA, T-RFLP). The heterotrophic activity values presented high variability during some periods; however, this was not reflected on the reactor performance. As sludge health indicator, the average activity in a period was better than individual values. Although all the carbon removal mechanisms are still unclear for this process, they seemed to be influenced by non-respirometric ways (storage, biosorption, accumulation, etc.). The variability of heterotrophic activity could be correlated with the bacterial population diversity over time. Despite the high variability of the activity, a simple kinetic model (pseudo ASM1) based on apparent constant parameters was developed and calibrated. Such modellisation provided a good tool for control purposes.     

Determination of the potency of hexyl‐ciprofloxacin molecules that interact with gold nanoparticles in a reversible manner

This work determined the potency of hexyl‐ciprofloxacin molecules that reversibly interact with gold nanoparticles (AuNPs) passivated with 11‐mercaptoundecanoic acid (MUA) on Escherichia coli cells. For this, partition of modified antibiotic between different compartments of the gold colloid was determined using analytical techniques. First, concentration of hexyl‐ciprofloxacin was determined in the continuous phase of the colloid. Subsequently, the colloid was exposed to a volume of organic immiscible solvent and concentration of the transferred molecules was determined in the organic phase. Comparison of the amount of hexyl‐ciprofloxacin in each phase revealed that interaction between molecules and nanoparticles was reversible. Later, this work determined the potency of a population of hexyl‐ciprofloxacin molecules contained in a volume of the colloid, and the potency of other population of molecules that only interact with the continuous phase of the colloid. The absolute difference between these two values was proportional to the potency of a number of molecules that interact with the nanoparticles of the colloid.Inspec keywords: organic compounds, nanoparticles, gold, colloids, microorganisms, molecular biophysics, drug delivery systems, nanomedicineOther keywords: continuous phase, hexyl‐ciprofloxacin molecules, gold nanoparticles, gold colloid, 11‐mercaptoundecanoic acid, Escherichia coli cells, modified antibiotics, RP‐HPLC, organic immiscible solvent, reversible interaction, Au     

Monitoring of carboxylic carbon nanotubes in surface water by using multiwalled carbon nanotube-modified filter as preconcentration unit

In this paper, for the first time, the possibility of preconcentrating and determining carboxylic single-walled carbon nanotubes (c-SWNTs) from environmental water samples is demonstrated. The method is based on the preconcentration of c-SWNTs and their further electrophoretic analysis. The preconcentration of c-SWNTs has been successfully performed on a filter modified with multiwalled carbon nanotubes (MWNTs), which allows the use of high preconcentration rates. MWNT-modified filters were fabricated in the laboratory from a surfactant dispersion of MWNTs. The main variables affecting the preconcentration of analytes are studied and discussed in the paper. Electrophoretic separation of carboxylic SWNTs was accomplished by using a 50 mM ammonium acetate solution at pH 7.5 as a background electrolyte and a potential of 15 kV. Under these conditions, separation was completed within only 5 min. Recoveries for the analysis of spiked samples ranged from 70 to 85% and the precision from 6.4 to 7.3%.     

ATR-FT-IR membrane-based sensor for integrated microliquid-liquid extraction and detection

A novel straightforward membrane-based sensor, which uses attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy has been developed. The flow cell designed permits the on-line microliquid-liquid extraction of the target analyte into a organic solvent layer (OSL), which was deposited on the ATR surface using a sequential injection manifold. The aqueous and organic phases are separated via a commercial hydrophobic membrane placed on the PTFE piece of the cell. The main advantage of the proposed device is that the OSL can be created and regenerated in a continuous manner using the automatic manifold without opening the cell. The analytes are enriched into the OSL after diffusion through the membrane, which excludes the typical absorption bands of water. In addition, the behavior of different organic solvents was evaluated in order to increase the applicability and versatility of the proposed system. Finally, the analytical performance of the design was established for the detection and quantitation of Triton X100 in water.     

Autoanalyzer for milk quality control based on the lactose,fat, and total protein contents

A novel autoanalyzer was developed to assess the quality of milk samples according to the percentage of lactose, fat, and total protein they contain. The module comprises two pumps (one of high pressure), an injection valve, a filter, and an evaporative light-scattering detector. A volume of 15 microL of dilute milk was injected in an ethanol-water (50% v/v) stream for precipitation/retention of protein/fat, being the lactose content determined in the filtrate. The fat fraction was calculated using an ethanol stream, and total protein was finally dissolved by means of a 1.7 mol/L acetic acid solution. The simplicity of the proposed automatic module lies in the universal response of the detector, which permits the determination of the three macrocomponents in milk. In addition, the flow injection method allows their sequential analysis in the same injected sample by using selective reagents for each compound. The proposed method was validated with an SRM milk sample as well as by comparison of the results obtained with those provided by the IR method. In addition, the proposed analyzer is cheaper than its counterpart that is based on infrared technique.     

Nucleotide sequence and chromosomal localization of the gene encoding the old yellow enzyme from Kluyveromyces lactis

A 6·6 kb genomic DNA fragment from the yeast Kluyveromyces lactis was isolated. Sequence analysis of this fragment revealed the presence of two incomplete open reading frames (ORFs) in one strand, one coding for the carboxyl terminus of the plasma membrane H⁺-ATPase and the other for the amino terminus of an unidentified product. In the complementary strand, a full-length ORF which encodes for a protein homologous to the yeast NADPH-dependent Old Yellow Enzyme was found. The deduced amino acid sequence of this ORF predicts a protein of 398 residues with 84% similarity in its full length to OYE1 from Saccharomyces carlsbergensis and OYE2 from Saccharomyces cerevisiae. In addition, an internal region showed considerable similarity to the bile acid-inducible polypeptide from Eubacterium sp., to the NADH oxidase from Thermoanaerobium brockii, to the trimethylamino dehydrogenase from bacterium W₃A₁ and to the estrogen-binding protein from Candida albicans, suggesting a functional or structural relationship between them. Inactivation of the KYE1 (K luyveromyces Y ellow E nzyme) gene by deletion of 0·6 kb fragment between positions +358 and +936 produced viable cells with a slight increase in their generation time. Haploid cells carrying the disrupted allele showed one-third of the NADPH oxidase activity, compared to wild-type cells. Southern blotting analysis of digested DNA and chromosomes separated by contour-clamped homogeneous electric field electrophoresis from K. lactis indicated that this is a single-copy gene and it is localized on chromosome II, whose molecular size has been estimated to be approximately 1·3 Mb. The sequence reported in this paper has been deposited in the GenBank data base (Accession No. L37452).     

Water-induced coacervation of alkyl carboxylic acid reverse micelles: phenomenon description and potential for the extraction of organic compounds

Coacervates made up of alkanoic (C8-C16) and alkenoic (C18) acid reverse micelles were described for the first time, and their potential for the extraction of organic compounds prior to liquid chromatography was examined. The coacervation process occurred in miscible binary mixtures of water and a variety of protic and aprotic solvents. The phase behavior of alkyl carboxylic acids was found to be a function of both the Hildebrand solubility parameter, delta, and the hydrogen-bonding capability of the solvent. The best solvents for analytical extractions were those featuring the lowest delta values. The phase behavior of alkyl carboxylic acid/water/tetrahydrofuran (THF) ternary systems as a function of component concentration, pH, ionic strength, and temperature was investigated. The efficiency and the time required for phase separation depended on the experimental procedure used (i.e., standing, centrifugation, stirring, and sonication). The formation of alkyl carboxylic acid reverse micelles in THF was proven using both hydrophilic fluorescent probes and scattered light measurements. The structure of the coacervates consisted of spherical droplets dispersed in a continuous phase. Phase volume ratios were a function of both alkyl carboxylic acid and THF concentration. The low volume obtained (e.g., 1.5 microL per mg of decanoic) compared to that obtained by other coacervates (e.g., 5.1 microL per mg of dodecane sulfonic acid and 11.3 microL per mg of Triton X-114) greatly improved the concentration factors reached by coacervation-based extractions. Parameters affecting the extraction efficiency were assessed. Analytes in a wide range of polarity were efficiently extracted on the basis of the hydrophobic (e.g., PAHs) and hydrogen bond (e.g., chlorophenols, bisphenols, pesticides, phthalates, nonionic surfactants, dyes, and photographic developers) interactions that reverse micelles can establish. The coacervates were compatible with the chromatographic determination of analytes following UV or MS detection. They were successfully applied to the extraction of alkylphenol ethoxylates (octyl and nonyl) and alcohol ethoxylates (C12-C16) from influent and effluent wastewater and river water samples. Nonionic surfactants in the coacervate were directly separated and quantified by liquid chromatography-ion trap mass spectrometry. Concentration factors were around 160. The recovery of nonionics in the environmental water samples ranged from 90 to 104%.