bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Freshwater Planarians Dugesia (Girardia) tigrina Testing Toxicity of a Petroleum Refinery Wastewater
Authors: Barros Gislaine Silva , Angelis D. F. , Furlan L. T. , Corrêa-Junior B.
Published: March 2010

The action of wastewater from Paulínia Petroleum Refinery (REPLAN) was tested in freshwater planarian regeneration, from the species Dugesia (Girardia) tigrina. This chronic toxicity test was realized to establish conditions to use them as a monitoring species of the refinery treatment efficiency. The tested samples wore collected at six points: rio Jaguari (REPLAN water intake); wastewater beginning biological treatment (after physical treatment); wastewater entering stabilization lagoon (last stage of treatment); discharge of stabilization lagoon; upstream from effluent discharge at rio Atibaia; downstream from the effluent discharge. Drinking water was used as control. Five or eight adult planarian at regeneration stage was tested in each point. The adult tested specimens were selected and weren’t feed during the experiment. The test was initiated immediately after the removal of planarian’s head (cut with blade) and finalized when the regeneration was complete. It was detected high toxic effect only at the sample from the primary treatment discharge, before realizing the aeration and biological treatment. We can conclude that REPLAN effluent, at the end of the treatment process don’t cause any effect in Dugesia (Girardia) tigrina cephalic regeneration.
Fenarimol Effects on the Animal Development and Rats Reproduction
Authors: Castro Vera , Scramin S. , Melo M.
Published: March 2010

The search of biomarkers of effects due to the non-target organisms’ exposure to fungicides is intensifying. Nowadays, the alterations of biochemical and of developmental parameters are among the measures of events most studied as possible biomarkers depending of the critical periods in the development; since many of these products alter several aspects of the reproductive system. Beyond the biomarker used traditionally as fertility percentage, abortions and still-born, other parameters related to the reproductive physical development were added; and in vitro establishment of the method for evaluation of the possible pesticides interference in CYP19 aromatase activity, that catalyzes the conversion of androgens in estrogens. In this work, it was evaluate the possible effects of the fungicide Fenarimol after perinatal exposure, since the fenarimol placental transport increases from the 18th gestational day and is excreted via maternal milk. The females Wistar rats were exposed to 150 or 300 mg.kg–1 of Fenarimol (S.C.) during the initial or final gestational period or during the six first days of suckling. Both studied doses, in spite of having affected the observed physical parameters in a punctual way, did not cause clear evidence of a dose-response effect to Fenarimol within the same phase (gestation and lactation). Such observations emphasize the importance of these products prospective studies, with the biomarkers use that may evidence subtle alterations. The obtained data of more sensitive targets will be able to contribute for the amelioration of the methods and polices that are able to minimize the risks regarding the environmental health. Thus, it is being adapted the method for the evaluation of possible fungicide interference in aromatase activity, in which are used mice liver microsomes as enzyme source to be evaluated at the presence of Fenarimol.
Hydrothermal Vents as a Possible Natural Pollution Laboratory: Metal Detoxification Mechanisms in Mussels and Fishes from Lucky Strike
Authors: Company Rui , Serafim A. , Felícia H. , Cosson R. , Fiala-Médioni A. , Bebianno M. J.
Published: March 2010

Deep-sea hydrothermal vent environments are considered highly toxic with high temperatures, sulphide, methane, carbon dioxide and heavy metals. Paradoxically, life at the vents exhibits high productivity and therefore provides a unique way to study the effect of long-term adaptation to environmental stress. The aim of this study was to compare the responses of some biomarkers of metal exposure between two hydrothermal species, the mussel Bathymodiolus azoricus and the chimaera fish Hydrolagus pallidus from Lucky Strike vent field. Results show high metal levels in B. azoricus compared to their coastal counterparts, especially for Ag, Cd, Cu and Zn in the gills. However, metallothionein (MT) levels were surprisingly low taking into account the metal accumulation. H. pallidus also exhibited significantly higher metal concentrations in the gills than the muscle, however with MT levels 2-fold higher in the muscle. Superoxide dismutase (SOD) and catalase (CAT) activities in the mussels were significantly higher in the gills, while glutathione peroxidases (GPx) were present mainly in the mantle, suggesting the two tissues have different antioxidant responses to deal with stress factors. Lipid peroxidation (LPO) was more evident in the gills, indicating that defence mechanisms in this tissue may not be completely effective against metal toxicity. Although the major food source for H. pallidus consists in metal overloaded mussels, no evidences of metal bioamplification were found. Chimaeras may possess other detoxification mechanisms that can be more important than MT.
Effects of the Microcystis aeruginosa Strain RST9501 from Patos Lagoon, RS, on Growth and Reproduction of the Cladocera Ceriodaphnia dubia
Authors: Coimbra Nade Janara , Yunes J. S. , Bohrer-Morel M. B.
Published: March 2010

This study evaluates the toxicity of the Microcystis aeruginosa strain RST9501, isolated from Patos Lagoon, to cladocerans using standard tests with Ceriodaphnia dubia. The strain RST9501 was compared with the non-toxic M. aeruginosa strain NPJT-01. Chronic effects were estimated by evaluating reproduction and growth in C. dubia exposed to increasing concentrations of M. aeruginosa. Alternative food source constituted by Pseudokirchneriella subcapitata and Artemia chow was made available for all treatments. The presence of the two strains of M. aeruginosa inhibited both reproduction and growth in C. dubia. Also, regardless the presence of microcystin, there was an increase in toxicity as the cell concentration of both strains increased.
Laboratory Study of Arsenic Accumulation and Toxicity in Eichhornia crassipes and Salvinia auriculata
Authors: Guimarães Fernanda Pereira , Gomes C. Q. , Magalhães A. B. S. , Freitas T. V. , Oliveira J. A. , Aguiar R.
Published: March 2010

The evaluation of the toxicity effects of arsenic (As) and the tolerance potential of Eichhornia crassipes and Salvinia auriculata regarding to this element, is an important step in the selection of plants for the purpose of phytoremediation. Both species were collected at clean water bodies, disinfected, acclimatized and submitted to treatments with As as sodium arsenate at the concentrations: 0, 0.5, 2.5 and 5.0 mg.L–1. After seven days of exposure to As, the plants were washed in a solution of HCl 0.1N. Shoot and root tissues were separated, dried and weighed. The As content analyses were carried out by acid digestion of dried tissue samples followed by measurement of total concentration of arsenic by Inductively-Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The results indicate that S. auriculata accumulated more As, presenting marginal necroses in leaves, while, E. crassipes didn’t present any visible morphological alteration. The As absorption for both species increased substantially with the external concentration and S. auriculata was more sensitive. This effect was found either for roots and shoots in both species, highlight, the higher accumulation in roots. In the treatment of 5.0 mg.L–1 S. auriculata accumulated in roots an average of 146.66 μg As g–1 dry weight and E. crassipes accumulated 56.29 μg g–1 As dry weight. Probably, the highest As accumulation in this concentration in both species, was caused by the highest proportion of arsenic/phosphate in the solution, since the arsenate absorption competes with phosphate. It was observed, along the experiment, that the “parent” plants of S. auriculata, although with leaves damaged, produced “daughter” plants healthy. This probably tolerance mechanism can be related to some process that blocks the translocation of arsenic to “daughter” plants or can be a process of acclimatization to the pollution.
Modulatory Effect of Extract of Stryphnodendron adstringens Mart. (Barbatimão) Against Induced Damage by Mitomicyn C in Mice
Authors: Silva-de-Andrade L. , Barros-de-Castro D. , Chen-Chen Lee
Published: March 2010

Stryphnodendron adstringens (Martius) Coville (Leguminosae), popularly known as “barbatimão”, is a medicinal plant that grows in the central Savannas of Brazil. Decoctions or infusions of the stem bark are traditionally used by the native population of Brazil in the treatment of leukorrhea, diarrhea and as an anti-inflammatory medicine. The aim of this study was to evaluate the antigenotoxicity effect of ethanolic extract of barbatimão (EEB) against induced damage by mitomycin C (MMC) by the bone marrow micronucleus test in mice. Doses of EEB (50 mg/kg, 100 mg/kg e 200 mg/kg) and MMC (4 mg/kg) were administered simultaneously by intraperitonial injection (i.p.) in groups of 5 (five) animals for treatment. The positive control received a MMC i.p. (4 mg/kg) and negative control, distilled and sterilized H2O. Cytological preparations were done according Heddle (1973). For all the doses, micronucleated polychromatic erythrocytes frequency (MNPCE) was evaluated at period of 24 h. The obtained results showed no significantly inhibition of MNPCE frequency (mean = 28.6; SD = 1.67) in the dose of 50 mg/kg of EEB compared to positive control (mean = 30.6; SD = 2.70) (p > 0.05). However, the EEB in doses of 100 mg/kg (mean = 19.8; SD = 2.28) and 200 mg/kg (mean = 16.8; SD = 2.58) suppressed significantly the frequency of MNPCE induced by MMC (p < 0.05). Thus, the results indicated that the EEB exhibited antigenotoxic activity in bone marrow of mice.
Spatial Distribution of Mercury Concentration in Suspension Solids of the Upper Madeira River, Rondônia
Authors: Gomes João Paulo de Oliveira , Nascimento E. L. do , Almeida R. , Bastos W. R. , Bernardi J. V. E. , Barros P. R. H. B. de
Published: March 2010

The main goal of this work was going to study the spatial distribution of mercury in suspension solid in the upper Madeira river, comprehended between its formation by Beni and Mamoré rivers until Porto Velho’s city, using geostatistical analysis techniques. The samplings were performed in November 22th to 29th, 2003, and soon after, the total mercury was determined by atomic absorption spectrophotometer coupled cold vapor generation. The results revealed average increase in Hg concentrations at the Upper Madeira river, from its formation (Beni and Mamoré rivers) and along its course, but mostly in the area of its main right bank affluents (Jaci-Paraná and Mutum-Paraná rivers), demonstrated by Pontual Kriging technique. The geostatistical technique used allowed to observe important increase of Hg in the main tributaries, which suggests the natural source of Hg or its redisponibilization from forests areas near gold mining by the regional land use.
Toxicological Evaluation of the Hexadecanoic Acid and β Sitosterol for Daphnia similis Claus, 1876 (Cladoceran, Crustacean)
Authors: Sobreira Romena Galvani , Heid-Furley T. , Effigen J. I. , Oliveira-Filho A. C. de
Published: March 2010

The wood used as raw material by cellulose and paper factories has high levels of extractives with high toxic potential, such as fatty acids and the phytosterol β sitosterol, which promote toxic effects (masculinization of females, among others) in aquariums such as fish and invertebrates. Due to the growing concern about the environment in Brazil, factories such as Aracruz Celulose S.A. routinely carry out ecotoxicological tests to evaluate the effects of their effluents on the environment and anticipate possible environmental problems. The present study was carried out in two stages with the objective of relating the toxicity of the mixed effluent from Aracruz Celulose with some of the reference extractives. The first stage consisted of identifying and quantifying fatty acids and β-sitosterol present in sectoral effluents through chromatographic analysis. In the second stage, ecotoxicological analyzes were carried out with two of the most abundant extractives and with the mixed (untreated) effluent, to assess whether the acute toxicity of this effluent for the organism Daphnia similis is related to the current concentrations of the extractives tested. The quantification of extractives present in Aracruz Celulose's sectoral effluents showed that effluents from purification, acid bleaching and evaporation developed with the highest concentrations of these compounds, while effluents from the wood yard and alkaline bleaching developed with the lowest values. Linoleic, hexadecanoic, hexacosanoic, octadecenoic and docosanoic fatty acids were the most abundant, and β sitosterol was identified in all effluents analyzed, being in higher concentration in the purification effluent. The chosen extractives did not present acute toxicity to test organisms, even at concentrations ten times greater than those present in Aracruz Celulose's sectoral effluents, however, the results of the three mixed effluent toxicity tests for D. similis showed acute toxicity, with EC50 equal to 16.66%, 23.62% and 52.02%.
Toxicological Effect of Soapberry, Paullinia clavigera (Sapindaceae) on Daphnia magna and on Two Biological Control of Agriculture Pests
Authors: Iannacone José , Alvariño L. , Salcedo C.
Published: March 2010

Soapberry, Paullinia clavigera Simpson (Sapindaceae) is used as a craft insecticide in Peruvian Amazon. The aim of the current research was to evaluate the toxicological effect of P. clavigera proceeding of Pucallpa, Peru, on Daphnia magna Strauss, 1820 (Crustacea: Daphniidae), and on two biological controls of agriculture pests: Copidosoma koehleri Blanchard, 1940 (Hymenoptera: Encyrtidae), and Chrysoperla externa (Hagen 1861) (Neuroptera: Chrysopidae). In D. magna (LC50 at 48 h exposure), the highest effects were found with leaves (LC50 = 237 mg L–1) and stem cortex (LC50 = 398 mg L–1) chlorophormic extracts. In C. koehleri (LC50 at 48 h exposure and emergence of adults), only hexanic extracts of leaves (LC50 = 145 mg L–1; 38.9%) and stem cortex (LC50 = 298.6 mg L–1; 16.8%) produced effects on mortality and emergency of adults, respectively. Toxicological effects of stem cortex chlorophormic botanic extracts on larvae of C. externa (at 96 h of exposure) were not found. Leaves and stem cortex ethanolic extracts had the most potential for use in an integrated pest management (IPM) because they were less toxic and selective to biological control and for D. magna in the freshwater environment.
Extraction and Concentration of Freshwater – and Seawater – Derived Dissolved Organic Matter for Use in Aquatic Toxicology Studies
Authors: Rodrigues S. C. , Bianchini Adalto
Published: March 2010

Dissolved organic matter (DOM) is defined as the organic matter that passes through a 0.45 μm-mesh filter. Recent studies have shown the DOM importance in mitigating trace metals and organic pollutants toxicity. In general, studies with DOM are performed using commercial organic matter. However, it has been demonstrated that this organic matter has little structural similarity with the aquatic humic acids. Furthermore, a natural DOM is composed by different fractions, which can exhibit different complexing properties with metals. Thus, it is important to evaluate the effect of different sources of natural DOM on pollutants toxicity. To use natural DOM in aquatic toxicity tests, it is necessary to extract and provide suitable storage for samples in the laboratory. The ideal process for DOM isolation from natural waters should be capable of rapidly and effectively extracting large quantities of DOM from water without fractionation, chemical alteration and/or other losses. Therefore, in the present paper we describe the methodological approaches currently in use in our laboratory for extraction and concentration of both freshwater and seawater-derived DOM using reverse osmosis (freshwater) and solid phase extraction (seawater).
Quanto Options
Authors: Wystup Uwe
Published: March 2010

A quanto option can be any cash‐settled option, whose payoff is converted into a third currency at maturity at a prespecified rate, called the quanto factor. This allows the buyer to hedge the foreign exchange conversion risk. Any (exotic) option contract can be “quantoed” into the home currency of the investor.
Stochastic Differential Equations with Jumps: Simulation
Authors: Bruti‐Liberati Nicola , Platen Eckhard
Published: March 2010

In finance and economics the key dynamics are often specified via stochastic differential equations (SDEs) of jump‐diffusion type. The class of jump‐diffusion SDEs that admits explicit solutions is rather limited. In this paper we give a brief overview on strong and weak discrete time approximations for solutions of SDEs with jumps.
Combustion Fundamentals
Authors: Janbozorgi Mohammad , Far Kian Eisazadeh , Metghalchi Hameed
Published: March 2010

The sections in this article are

Introduction

Combustion Thermodynamics

Enthalpy of Reaction

Flame Temperature

Chemical Equilibrium

Chemical Kinetics

Combustion Chemical Reactions

Kinetic Rate Equations

Chemical Time Scales and Nonequilibrium Effects

Kinetics Simplification and Reduction

Rate‐Controlled Constrained‐Equilibrium (
RCCE
) Method

Laminar Premixed Flames

Governing Equations

Experimental Approach

Laminar Burning Speed Measurement Techniques

Diffusion Flames

Conclusions
Recent Advances in the Study of Structural Materials Compatibility with Hydrogen
Authors: Dadfarnia M. , Novak P. , Ahn D. C. , Liu J. B. , Sofronis P. , Johnson D. D. , Robertson I. M.
Published: March 2010

Hydrogen is a ubiquitous element that enters materials from many different sources. It almost always has a deleterious effect on mechanical properties. In non‐hydride‐forming systems, research to date has identified hydrogen‐enhanced localized plasticity and hydrogen‐induced decohesion as two viable mechanisms for embrittlement. However, a fracture prediction methodology that associates macroscopic parameters with the degradation mechanisms at the microscale has not been established, as of yet. In this article, we report recent work on modeling and simulation of hydrogen‐induced crack initiation and growth. Our goal is to develop methodologies to relate characteristics of the degradation mechanisms from microscopic observations and first‐principles calculations with macroscopic indices of embrittlement. The approach we use involves finite element analysis of the coupled hydrogen transport problem with hydrogen‐assisted elastoplastic deformation, thermodynamic theories of decohesion, and ab initio density functional theory calculations of the hydrogen effect on grain boundaries.
Copper(II) Bromide/Boron Trifluoride Etherate‐Cocatalyzed Cyclization of Ketene Dithioacetals and p‐Quinones: a Mild and General Approach to Polyfunctionalized Benzofurans
Authors: Liu Yingjie , Wang Mang , Yuan Hongjuan , Liu Qun
Published: March 2010

A new application of copper(II) bromide‐activated ketene dithioacetals as nucleophiles in organic chemistry has been developed. Under the cocatalysis of copper(II) bromide (2.0 mol%) and boron trifluoride etherate (10 mol%), the conjugate addition and sequential cyclization of α‐electron‐withdrawing group‐substituted ketene dithioacetals with p‐quinones in acetonitrile at room temperature gave a variety of benzofurans. This formal [3+2] cycloaddition provides a general method for catalytic synthesis of polyfunctionalized benzofurans with the advantages of readily available starting materials, cheap catalysts, mild reaction conditions, good yields and wide range of synthetic potential for the benzofuran products. Further transformations of the resulting benzofurans to 2‐aminobenzofurans and benzofuro[2,3‐d]pyrimidine derivatives are also investigated.
Silver‐Catalyzed Aldehyde Olefination Using Siloxyalkynes
Authors: Sun Jianwei , Keller Valerie A. , Meyer S. Todd , Kozmin Sergey A.
Published: March 2010

We describe the development of a silver‐catalyzed carbonyl olefination employing electron‐rich siloxyalkynes. This process constitutes an efficient synthesis of trisubstituted unsaturated esters, and represents an alternative to the widely utilized Horner–Wadsworth–Emmons reaction. Excellent diastereoselectivities are observed for a range of aldehydes using either 1‐siloxy‐1‐propyne or 1‐siloxy‐1‐hexyne. This mild catalytic process also enables chemoselective olefination of aldehydes in the presence of either ester or ketone functionality. Furthermore, since no by‐products are generated, this catalytic process is perfectly suited for development of sequential reactions that can be carried out in a single flask.
A Simple, Effective Boron‐Halide Ethoxylation Catalyst
Authors: Moloy Kenneth G.
Published: March 2010

Boron esters B(OR)3, readily derived from boric acid and alcohols, combine with iodide or bromide to catalyze the ethoxylation of alcohols and phenols, giving good rates and narrow product distributions. The combined action of a weak electrophile [B(OR)3] and a weak nucleophile (halide) allows for the ethoxylation of base‐sensitive alcohols. Experiment suggests a new mechanism for this commercially important reaction proceeding through key β‐haloalkoxy intermediates.
Microbial systems engineering: First successes and the way ahead
Authors: Dietz Sven , Panke Sven
Published: March 2010

The first promising results from “streamlined,” minimal genomes tend to support the notion that these are a useful tool in biological systems engineering. However, compared with the speed with which genomic microbial sequencing has provided us with a wealth of data to study biological functions, it is a slow process. So far only a few projects have emerged whose synthetic ambition even remotely matches our analytic capabilities. Here, we survey current technologies converging into a future ability to engineer large‐scale biological systems. We argue that the underlying synthetic technology, de novo DNA synthesis, is already rather mature – in particular relative to the scope of our current synthetic ambitions. Furthermore, technologies towards rationalizing the design of the newly synthesized DNA fragment are emerging. These include techniques to implement complex regulatory circuits, suites of parts on a DNA and RNA level to fine tune gene expression, and supporting computational tools. As such DNA fragments will, in most cases, be destined for operating in a cellular context, attention has to be paid to the potential interactions of the host with the functions encoded on the engineered DNA fragment. Here, the need of biological systems engineering to deal with a robust and predictable bacterial host coincides with current scientific efforts to theoretically and experimentally explore minimal bacterial genomes.
Heat Effects upon Electrochemical Copper Deposition on Polycrystalline Gold
Authors: Etzel Kai D. , Bickel Katrin R. , Schuster Rolf
Published: March 2010

Heat effects upon Cu deposition on polycrystalline Au surfaces from sulphuric acid electrolytes were calorimetrically measured. By combination of pyroelectric temperature detection at the backside of a thin electrode foil with pulsed electrochemistry, sensitivities to electrochemical conversions of a few percent of a Cu monolayer (ML), corresponding to about 1 μJ cm−2 were achieved. We compared the heat evolution upon Cu under potential deposition (UPD), Cu deposition onto a fully developed Cu UPD layer and bulk Cu deposition onto a 300 ML thick Cu layer on Au. The heat effects were measured dependent on the amplitudes of the applied potential steps, that is, the driving forces of the respective reactions. From the differences of the heat effects among the Cu deposition processes, we deduced implications on the reaction mechanisms. For Cu UPD, the heat effects were explicable by the deposition of 1.3 Cu atoms per two electrons flowing to the electrode accompanied by sulphate coadsorption, similar to Cu UPD from sulphuric acid solutions on Au(111). Upon Cu deposition on a Cu UPD layer the heat effects signal considerable anion coadsorption up to the deposition of about 0.5 ML of Cu. At higher conversions the deposition mechanism gradually changes towards bulk Cu deposition, accompanied by reduction of the sulphate coverage.
Cooperative spectrum sensing with imperfect feedback channel in the cognitive radio systems
Authors: Oh Dong‐Chan , Lee Yong‐Hwan
Published: March 2010

The primary object of cognitive radio is to increase spectral efficiency, while causing limited interference to primary users who are using the spectrum. Hence, an essential part of cognitive radio is a spectrum sensing that determines whether a particular spectrum is occupied or not by a primary user. However, the sensing decision of a local secondary user alone may not be reliable enough due to shadowing and multipath fading of wireless channels. Recently, cooperative spectrum sensing has emerged as a remedy to the problems of local sensing. To sense the spectrum in a cooperative manner, secondary users report their local decisions to a cognitive base station through a feedback channel that is subject to fading and shadowing. Therefore, though the local sensing result is obtained accurately, it might not be suitable for making a cooperative decision due to feedback error. To alleviate this problem, we propose a hard decision combining‐based cooperative spectrum sensing scheme in the presence of a feedback error caused by imperfect channel condition. In the proposed scheme, only the most favorable secondary users, those whose reporting channel conditions are peak, are allowed for cooperation. Through the proposed scheme, we can maximize the detection probability while guaranteeing that the desired false alarm probability is maintained. The simulation results show that the proposed scheme provides better spectrum sensing performance than the conventional scheme. Copyright © 2010 John Wiley & Sons, Ltd.
Broadening the Synthetic Scope of the Iron(III)‐Catalyzed Aza‐Prins Cyclization
Authors: Carballo Rubén M. , Valdomir Guillermo , Purino Martín , Martín Víctor S. , Padrón Juan I.
Published: March 2010

The nature and influence of the N‐sulfonyl group in aza‐Prins cyclization and the reactivity of the six‐membered aza‐cycle generated has been studied. The aza‐Prins cyclization of γ,δ‐unsaturated amines with a tosyl group at the nitrogen atom produces 2‐alkyl‐4‐halo‐1‐tosyl‐1,2,5,6‐tetrahydropyridines with a halovinyl function, extraordinarily stable to further derivatization and detosylation conditions. To modulate the reactivity of such aza‐cycles, a general study of the aza‐Prins cyclization reaction was performed with several sulfonamides. Ring formation occurs satisfactorily with both N‐nosyl and N‐mesylamines providing optimal conditions for further synthetic transformations. To exemplify the scope of this methodology, a short synthesis of the alkaloid coniine was successfully carried out.
Comparative Microbial Fuel Cell Evaluations of Shewanella spp.
Authors: Bretschger Orianna , Cheung Andrea C. M. , Mansfeld Florian , Nealson Kenneth H.
Published: March 2010

To date several different strains of Shewanella have been sequenced; however, many of these isolates have not been evaluated in microbial fuel cell (MFC) systems. Here we present a summary of power densities, current densities, cell attachment, and coulombic efficiencies for eight different Shewanella strains in two different MFC configurations. Our results show that different Shewanella strains have unique characteristics as MFC biocatalysts and that strain S. putrefaciens W3‐18‐1 significantly outperforms S. oneidensis MR‐1. Further, these results suggest that Shewanella strain performance in MFCs is strongly impacted by system parameters such as buffer composition and ion exchange membrane selection.
Enzymatic Anodes for Hydrogen Fuel Cells based on Covalent Attachment of Ni‐Fe Hydrogenases and Direct Electron Transfer to SAM‐Modified Gold Electrodes
Authors: Rüdiger Olaf , Gutiérrez‐Sánchez Cristina , Olea David , Pereira Inês A. C. , Vélez Marisela , Fernández Víctor M. , De Lacey Antonio L.
Published: March 2010

Immobilization of hydrogenases onto electrodes is of great interest for developing biofuel cells that use H2 as a fuel. In this way, hydrogenases replace Pt as electrocatalyst for oxidizing H2 in the anode. We have developed a method of covalent bonding of Desulfovibrio gigas Ni‐Fe hydrogenase and Desulfovibrio vulgaris Hildenborough Ni‐Fe‐Se hydrogenase to gold electrodes modified with a self assembled monolayer (SAM) of 4‐aminothiophenol for measuring high electrocatalytic currents of H2‐oxidation in the absence of redox mediators. Electrochemical measurements and atomic force microscopy characterization show that direct electron transfer between enzyme and the Au support is due to formation of an organized monolayer of hydrogenase over the SAM‐modified surface.
Development of a Chitosan Scaffold Electrode for Fuel Cell Applications
Authors: Lau Carolin , Martin Georgianna , Minteer Shelley D. , Cooney Michael J.
Published: March 2010

Hydrophobically modified chitosan has been proposed for enzyme immobilization and stabilization at bioelectrodes in biofuel cells. In this paper, we analytically evaluate the attributes of employing hydrophobically modified chitosan molded into high porosity scaffolds to improve enzyme activity and mass transport of malate dehydrogenase bioelectrodes. Results suggest that the hydrophobically modified chitosan can alter catalytic activity of malate dehydrogenase and that scaffold structure improves power density over chitosan thin films. Fluorescence measurements are also presented that correlate the improved activity to alterations in the amphiphilic nature of the chemical microenvironment (immediately surrounding the enzyme) that the modified chitosan affords. Commentary is also given on how mass transport through the chitosan matrix can be improved in order to achieve higher power densities.
The Role of Shewanella oneidensis MR‐1 Outer Surface Structures in Extracellular Electron Transfer
Authors: Bouhenni Rachida A. , Vora Gary J. , Biffinger Justin C. , Shirodkar Sheetal , Brockman Ken , Ray Ricky , Wu Peter , Johnson Brandy J. , Biddle Eulandria M. , Marshall Matthew J. , Fitzgerald Lisa A. , Little Brenda J. , Fredrickson Jim K. , Beliaev Alexander S. , Ringeisen Bradley R. , Saffarini Daad A.
Published: March 2010

The ability of the metal reducer Shewanella oneidensis MR‐1 to generate electricity in microbial fuel cells (MFCs) depends on the activity of a predicted type IV prepilin peptidase; PilD. Analysis of an S. oneidensis MR‐1 pilD mutant indicated that it was deficient in pili production (Msh and type IV) and type II secretion (T2S). The requirement for T2S in metal reduction has been previously identified, but the role of pili remains largely unexplored. To define the role of type IV or Msh pili in electron transfer, mutants that lack one or both pilus biogenesis systems were generated and analyzed; a mutant that lacked flagella was also constructed and tested. All mutants were able to reduce insoluble Fe(III) and to generate current in MFCs, in contrast to the T2S mutant that is deficient in both processes. Our results show that loss of metal reduction in a PilD mutant is due to a T2S deficiency, and therefore the absence of c cytochromes from the outer surface of MR‐1 cells, and not the loss of pili or flagella. Furthermore, MR‐1 mutants deficient in type IV pili or flagella generated more current than the wild type, even though extracellular riboflavin levels were similar in all strains. This enhanced current generating ability is in contrast to a mutant that lacks the outer membrane c cytochromes, MtrC and OmcA. This mutant generated significantly less current than the wild type in an MFC and was unable to reduce Fe(III). These results indicated that although nanofilaments and soluble mediators may play a role in electron transfer, surface exposure of outer membrane c cytochromes was the determining factor in extracellular electron transfer in S. oneidensis MR‐1.
An L‐Lactate Amperometric Enzyme Electrode Based on L‐Lactate Oxidase Immobilized in a Laponite Gel on a Glassy Carbon Electrode. Application to Dairy Products and Red Wine
Authors: Zanini Veronica Paz , de Mishima Beatriz López , Labbé Pierre , Solís Velia
Published: March 2010

A biosensor based on the immobilization of Lactate oxidase in laponite–organosilasesquioxane films on glassy carbon electrode for the quantification of L‐lactate in wine and dairy products is presented. The bioelectrode showed a very high sensitivity (0.33±0.01) A cm−2 M−1 and a short time response (10 s) for less than 1 U of enzyme. No significant interferences, including ascorbic acid, were detected. For red wine, matrix effects assigned to polyphenols and anthocyanins were observed, which ware easily overcome by sample dilution. Our L‐lactate determinations were in good agreement with those of two standard methods.
Self‐Assembly of Gold Nanoparticles/Electroactive Polyelectrolyte Multilayer Films for Tunable Electrocatalysis
Authors: Liu Xiaoqing , Wang Fuan , Han Shuang , Shi Lihong , Xu Guobao
Published: March 2010

This study described fabrication, characterization, and application of multilayer films based on layer‐by‐layer assembly of ferrocene poly(ethylenimine) and gold nanoparticles. Assembly process of the multilayer film was investigated by atomic force microscopy, UV‐visible absorption spectroscopy and electrochemical impedance spectroscopy. The multilayer films exhibited a pair of well‐defined redox peaks as revealed by cyclic voltammetry, as well as bifunctional and fine‐tunable electrocatalysis for oxidation of ascorbic acid and reduction of oxygen. Both the outer layer and layer number had effect on the electrocatalytic response. Electrocatalytic activity of the films could be controlled with assemblies at the nanoscale level by simply adjusting deposition cycles or amount of component in the films.
Simultaneous Determination of Dihydroxybenzene Isomers at MWCNTs/β‐Cyclodextrin Modified Carbon Ionic Liquid Electrode in the Presence of Cetylpyridinium Bromide
Authors: Yu Qiong , Liu Yong , Liu Xiaoying , Zeng Xiandong , Luo Shenglian , Wei Wanzhi
Published: March 2010

Simultaneous determination of dihydroxybenzene isomers was investigated at a multi‐wall carbon nanotubes (MWCNTs)/β‐cyclodextrin composite modified carbon ionic liquid electrode in phosphate buffer solution (pH 7.0, 1/15 mol/L) in the presence of cationic surfactant cetylpyridinium bromide (CPB). With the great enhancement of surfactant CPB, the voltammetric responses of dihydroxybenzene isomers were more sensitive and selective. The oxidation peak potential of hydroquinone was about 0.024 V, catechol was about 0.140 V and resorcinol 0.520 V in differential pulse voltammetric (DPV) measurements, which indicated that the dihydroxybenzene isomers could be separated entirely. The electrode showed wide linear behaviors in the range of 1.2×10−7–2.2×10−3, 7.0×10−7–1.0×10−3, 2.6×10−6–9.0×10−4 mol/L for hydroquinone, catechol and resorcinol, respectively. And the detection limits of the three dihydroxybenzene isomers were 4.0×10−8, 8.0×10−8, 9.0×10−7 mol/L, respectively. The proposed method could be applied to the determination of dihydroxybenzene isomers in artificial wastewater, and the recovery was from 97.4% to 104.2%.
Delta2D and Proteomweaver: Performance evaluation of two different approaches for 2‐DE analysis
Authors: Millioni Renato , Miuzzo Manuela , Sbrignadello Stefano , Murphy Ellen , Puricelli Lucia , Tura Andrea , Bertacco Elisa , Rattazzi Marcello , Iori Elisabetta , Tessari Paolo
Published: March 2010

2‐DE is a fundamental technology used in proteomics research. However, despite its high capacity to simultaneously separate several proteins for subsequent identification and quantitative comparison studies, a drawback for this technique is its limited reproducibility, especially when comparing data from different laboratories. 2‐DE‐related variability can be broadly divided into two categories: experimental and post‐experimental. Experimental variability depends on physical and chemical parameters, whereas post‐experimental variability arises when gels are analyzed by different software packages, particularly when different workflows are followed. In this paper, we compared the analysis performance of two software packages, Delta2D and Proteomweaver, using both standard and experimental gel images. Using standard gel images, the false negative spot count was 50% lower, the false positive count was 77% lower, the true positive count was 19% higher and spot matching was 4% higher in Delta2D when compared to Proteomeweaver. Using experimental gel images, we found that the total amount of time taken to complete the analysis with Delta2D was 30% that of the time needed with Proteomweaver and required fewer user interventions. The differences between ease of use and workflow strategy of these programs is discussed.
Protein microarrays: Reduced autofluorescence and improved LOD
Authors: Walter Johanna‐Gabriela , Stahl Frank , Reck Michael , Praulich Inka , Nataf Yakir , Hollas Markus , Pflanz Karl , Melzner Dieter , Shoham Yuval , Scheper Thomas
Published: March 2010

In protein microarray performance, the choice of an appropriate surface is a crucial factor. Three‐dimensional substrates like nitrocellulose are known to have higher binding capacities than planar surfaces. Furthermore, they can enable the immobilization of proteins in a functional manner. One disadvantage of today's nitrocellulose‐based microarrays is the high background fluorescence, which can interfere with the detection of low‐abundance proteins. We have developed an innovative black nitrocellulose membrane‐based protein microarray that exhibits low autofluorescence in combination with increased sensitivity and improved LOD (limit of detection). The applicability of the novel material was demonstrated with main focus on reversed‐phase microarray experiments. In comparison to various commercially available microarrays, a higher sensitivity in regard to the spotted protein was achieved. In contrast to other porous nitrocellulose‐based microarrays, the black nitrocellulose provides a significant lower autofluorescence and background intensity.
Possibilities and limitations of modeling environmental exposure to engineered nanomaterials by probabilistic material flow analysis
Authors: Gottschalk Fadri , Sonderer Tobias , Scholz Roland W. , Nowack Bernd
Published: March 2010

Information on environmental concentrations is needed to assess the risks that engineered nanomaterials (ENM) may pose to the environment. In this study, predicted environmental concentrations (PEC) were modeled for nano-TiO2, carbon nanotubes (CNT) and nano-Ag for Switzerland. Based on a life-cycle perspective, the model considered as input parameters the production volumes of the ENMs, the manufacturing and consumption quantities of products containing those materials, and the fate and pathways of ENMs in natural and technical environments. Faced with a distinct scarcity of data, we used a probabilistic material flow analysis model, treating all parameters as probability distributions. The modeling included Monte Carlo and Markov Chain Monte Carlo simulations as well as a sensitivity and uncertainty analysis. The PEC values of the ENMs in the different environmental compartments vary widely due to different ENM production volumes and different life cycles of the nanoproducts. The use of ENM in products with high water relevance leads to higher water and sediment concentrations for nano-TiO2 and nano-Ag, compared to CNTs, where smaller amounts of ENM reach the aquatic compartments. This study also presents a sensitivity analysis and a comprehensive discussion of the uncertainties of the simulation results and the limitations of the used approach. To estimate potential risks, the PEC values were compared to the predicted-no-effect concentrations (PNEC) derived from published data. The risk quotients (PEC/PNEC) for nano-TiO2 and nano-Ag were larger than one for treated wastewater and much smaller for all other environmental compartments (e.g., water, sediments, soils). We conclude that probabilistic modeling is very useful for predicting environmental concentrations of ENMs given the current lack of substantiated data. Environ. Toxicol. Chem. 2010;29:1036–1048. © 2010 SETAC
Path forecast evaluation
Authors: Jordà Òscar , Marcellino Massimiliano
Published: March 2010

A path forecast refers to the sequence of forecasts 1 to H periods into the future. A summary of the range of possible paths the predicted variable may follow for a given confidence level requires construction of simultaneous confidence regions that adjust for any covariance between the elements of the path forecast. This paper shows how to construct such regions with the joint predictive density and Scheffé's S‐method of 1953. In addition, the joint predictive density can be used to construct simple statistics to evaluate the local internal consistency of a forecasting exercise of a system of variables. Monte Carlo simulations demonstrate that these simultaneous confidence regions provide approximately correct coverage in situations where traditional error bands, based on the collection of marginal predictive densities for each horizon, are vastly off the mark. The paper showcases these methods with an application to the most recent monetary episode of interest rate hikes in the US macroeconomy. Copyright © 2010 John Wiley & Sons, Ltd.
Antiapoptotic effects of anthocyanins on rotator cuff tenofibroblasts
Authors: Park Hyung Bin , Hah Young‐Sool , Yang Jin‐Won , Nam Jung‐Been , Cho Se‐Hyun , Jeong Soon‐Taek
Published: March 2010

Degeneration of the rotator cuff tendon, which involves apoptosis of the tenofibroblasts, is one of the most common shoulder problems that can lead eventually to a full‐thickness rotator cuff tendon tear. The current authors evaluated both the ability of anthocyanins, which are powerful antioxidants, to reduce apoptosis in oxidation‐stressed rotator cuff tenofibroblasts, and the molecular mechanism for this antiapoptotic action. Anthocyanins demonstrated a dose‐dependent ability to inhibit H2O2‐induced apoptosis in cultured tenofibroblasts, as assessed by MTT assay and FACS analysis. H2O2 increased the phosphorylation of extracellular regulated kinase1/2 (ERK1/2) and of c‐Jun N‐terminal kinase (JNK) and the production of reactive oxygen species (ROS). In contrast, treatment with anthocyanins decreased this activation of ERK1/2 and JNK, as confirmed by Western blot analysis, and reduced the production of ROS, as verified by fluorescent microscopic and FACS analyses. These findings suggest that anthocyanins, by suppressing JNK, ERK1/2, and intracellular ROS production, have a concentration‐dependent antiapoptotic effect on rotator cuff tenofibroblasts exposed to an oxidative stressor, and may have therapeutic potential. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1162–1169, 2010
Raman spectroscopic study of the mineral gerstleyite Na2(Sb,As)8S13·2H2O and comparison with some heavy‐metal sulfides
Authors: Frost Ray L. , Bahfenne Silmarilly , Keeffe Eloise C.
Published: March 2010

The mineral gerstleyite is described as a sulfosalt as opposed to a sulfide. This study focuses on the Raman spectrum of gerstleyite Na2(Sb,As)8S13·2H2O and makes a comparison with the Raman spectra of other common sulfides including stibnite, cinnabar and realgar. The intense Raman bands of gerstleyite at 286 and 308 cm−1 are assigned to the SbS3E antisymmetric and A1 symmetric stretching modes of the SbS3 units. The band at 251 cm−1 is assigned to the bending mode of the SbS3 units. The mineral stibnite also has basic structural units of Sb2S3 and SbS3 pyramids with C3v symmetry. Raman bands of stibnite Sb2S3 at 250, 296, 372 and 448 cm−1 are assigned to SbS stretching vibrations and the bands at 145 and 188 cm−1 to SSbS bending modes. The Raman band for cinnabar HgS at 253 cm−1 fits well with the assignment of the band for gerstleyite at 251 cm−1 to the SSbS bending mode. Raman bands in similar positions are observed for realgar AsS and orpiment As2S3. Copyright © 2010 John Wiley & Sons, Ltd.
Interfacial electronic properties of AuGaAs interfaces studied by photomodulation Raman spectroscopy (pump–probe technique)
Authors: El‐Brolossy T. A. , Negm S. , Talaat H.
Published: March 2010

Photomodulation Raman spectroscopy (PM‐RS) was employed to investigate the interfacial properties of Au: n‐type GaAs interfaces, using the forbidden longitudinal optical (LO) phonon scattering as a probe. In PM‐RS, the photomodulating pump beam (PB) is incident on the sample while the Raman measurements are in progress; hence, PM‐RS can be viewed as a pump–probe technique. The photogenerated carriers partly neutralize the surface charges, which decreases the interfacial field and consequently the intensity of forbidden LO scattering. Two molecular beam epitaxy (MBE) junctions of 80 Å Au on n‐type GaAs (001) substrate with two different doping densities were used. The total surface charge density and change in the band bending were obtained as a function of the PB intensity considering a constant depletion electric field for the lower doped sample. Furthermore, the interfacial minority carrier trap lifetime was determined through dynamical measurements of the PM‐RS intensity. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical profiling of PortuguesePinus pineaL. nuts
Authors: Evaristo Isabel , Batista Dora , Correia Isabel , Correia Paula , Costa Rita
Published: March 2010

BACKGROUND:The first detailed chemical characterisation of Portuguese pine nut(Pinus pinea L.)is reported concerning proximate composition, fatty acid, mineral and vitamin contents.

RESULTS:Based on the analysis of 27 different populations, pine nuts were characterised by high contents of fat (47.7 g per 100 g dry matter (DM)), protein (33.8 g per 100 g DM) and phosphorus (1130 mg per 100 g DM) and low contents of moisture (5.9 g per 100 g DM) and starch (3.5 g per 100 g DM). They were also found to be a good source of zinc, iron and manganese.

CONCLUSION:Mineral composition seemed to be most prone to variation, suggesting its potentially useful role in discriminating Mediterranean pine nuts. A significant variability was found in the nut composition of PortugueseP. pineapopulations. Copyright © 2010 Society of Chemical Industry
Utilisation of corn (Zea mays) bran and corn fiber in the production of food components
Authors: Rose Devin J , Inglett George E , Liu Sean X.
Published: March 2010

The milling of corn for the production of food constituents results in a number of low‐value co‐products. Two of the major co‐products produced by this operation are corn bran and corn fiber, which currently have low commercial value. This review focuses on current and prospective research surrounding the utilization of corn fiber and corn bran in the production of potentially higher‐value food components. Corn bran and corn fiber contain potentially useful components that may be harvested through physical, chemical or enzymatic means for the production of food ingredients or additives, including corn fiber oil, corn fiber gum, cellulosic fiber gels, xylo‐oligosaccharides and ferulic acid. Components of corn bran and corn fiber may also be converted to food chemicals such as vanillin and xylitol. Commercialization of processes for the isolation or production of food products from corn bran or corn fiber has been met with numerous technical challenges, therefore further research that improves the production of these components from corn bran or corn fiber is needed. Published 2010 by John Wiley & Sons, Ltd.