bluuebunny/crossref_metadata_2025 huggingface dataset:
When right is all that is left: plasticity of right‐hemisphere tracts in a young aphasic patient
Authors: Zipse Lauryn , Norton Andrea , Marchina Sarah , Schlaug Gottfried
Published: April 2012

Using an adapted version of Melodic Intonation Therapy (MIT), we treated an adolescent girl with a very large left‐hemisphere lesion and severe nonfluent aphasia secondary to an ischemic stroke. At the time of her initial assessment 15 months after her stroke, she had reached a plateau in her recovery despite intense and long‐term traditional speech‐language therapy (approximately five times per week for more than one year). Following an intensive course of treatment with our adapted form of MIT, her performance improved on both trained and untrained phrases, as well as on speech and language tasks. These behavioral improvements were accompanied by functional MRI changes in the right frontal lobe as well as by an increased volume of white matter pathways in the right hemisphere. No increase in white matter volume was seen in her healthy twin sister, who was scanned twice over the same time period. This case study not only provides further evidence for MIT's effectiveness, but also indicates that intensive treatment can induce functional and structural changes in a right‐hemisphere fronto‐temporal network.
Pediatric neuroimaging in early childhood and infancy: challenges and practical guidelines
Authors: Raschle Nora , Zuk Jennifer , Ortiz‐Mantilla Silvia , Sliva Danielle D. , Franceschi Angela , Grant P. Ellen , Benasich April A. , Gaab Nadine
Published: April 2012

Structural and functional magnetic resonance imaging (fMRI) has been used increasingly to investigate typical and atypical brain development. However, in contrast to studies in school‐aged children and adults, MRI research in young pediatric age groups is less common. Practical and technical challenges occur when imaging infants and children, which presents clinicians and research teams with a unique set of problems. These include procedural difficulties (e.g., participant anxiety or movement restrictions), technical obstacles (e.g., availability of child‐appropriate equipment or pediatric MR head coils), and the challenge of choosing the most appropriate analysis methods for pediatric imaging data. Here, we summarize and review pediatric imaging and analysis tools and present neuroimaging protocols for young nonsedated children and infants, including guidelines and procedures that have been successfully implemented in research protocols across several research sites.
Effects of perceptual experience on children's and adults’ perception of unfamiliar rhythms
Authors: Hannon Erin E. , Vanden Bosch der Nederlanden Christina M. , Tichko Parker
Published: April 2012

Rhythm and meter are fundamental components of music that are universal yet also culture specific. Although simple, isochronous meters are preferred and more readily discriminated than highly complex, nonisochronous meters, moderately complex nonisochronous meters do not pose a problem for listeners who are exposed to them from a young age. The present work uses a behavioral task to examine the ease with which listeners of various ages acquire knowledge of unfamiliar metrical structures from passive exposure. We examined perception of familiar (Western) rhythms with an isochronous meter and unfamiliar (Balkan) rhythms with a nonisochronous meter. We compared discrimination by American children (5 to 11 years) and adults before and after a 2‐week period of at‐home listening to nonisochronous meter music from Bulgaria. During the first session, listeners of all ages exhibited superior discrimination of isochronous than in nonisochronous melodies. Across sessions, this asymmetry declined for young children but not for older children and adults.
Introduction to The Neurosciences and Music IV: Learning and Memory
Authors: Altenmüller E. , Demorest S.M. , Fujioka T. , Halpern A.R. , Hannon E.E. , Loui P. , Majno M. , Oechslin M.S. , Osborne N. , Overy K. , Palmer C. , Peretz I. , Pfordresher P.Q. , Särkämö T. , Wan C.Y. , Zatorre R.J.
Published: April 2012

The conference entitled ``The Neurosciences and Music‐IV: Learning and Memory'' was held at the University of Edinburgh from June 9–12, 2011, jointly hosted by the Mariani Foundation and the Institute for Music in Human and Social Development, and involving nearly 500 international delegates. Two opening workshops, three large and vibrant poster sessions, and nine invited symposia introduced a diverse range of recent research findings and discussed current research directions. Here, the proceedings are introduced by the workshop and symposia leaders on topics including working with children, rhythm perception, language processing, cultural learning, memory, musical imagery, neural plasticity, stroke rehabilitation, autism, and amusia. The rich diversity of the interdisciplinary research presented suggests that the future of music neuroscience looks both exciting and promising, and that important implications for music rehabilitation and therapy are being discovered.
Glycans, galectins, and HIV‐1 infection
Authors: Sato Sachiko , Ouellet Michel , St‐Pierre Christian , Tremblay Michel J.
Published: April 2012

During sexual transmission, HIV‐1 must overcome physiological barriers to establish a founder cell population. Viral adhesion represents a bottleneck for HIV‐1 propagation that the virus widens by exploiting some specific host factors. Recognition of oligomannosyl glycans of gp120 by C‐type lectins is one such example. Recent works suggest that complex glycans of gp120 are recognized by another host lectin, galectin‐1. This interaction results in rapid association of HIV‐1 to susceptible cells and facilitates infection. The peculiar presentation of complex glycans on gp120 seems to impart specificity for galectin‐1, as another member of the same family, galectin‐3, is unable to bind gp120 or enhance HIV‐1 infection. Other studies have shown that galectin‐9 could also increase HIV‐1 infectivity but via an indirect mechanism. Thus, current research suggests that galectins play various roles in HIV‐1 pathogenesis. Drug discovery approaches targeting host lectins at early steps could benefit the current arsenal of antiretrovirals.
Therapeutic Change in Colombian Families Dealing With Violence: Therapists, Clients, and Referring Systems in Conversation
Authors: Ripoll‐Núñez Karen , Villar‐Guhl Carlos Felipe , Villar‐Concha Eduardo
Published: April 2012

There is a gap in the Marriage and Family Therapy literature regarding clients’, therapists’, and family judges’ theories of change in relational therapy for family violence. We conducted in‐depth interviews with eleven court‐referred families, their therapists, and two family judges in Bogota, Colombia. Interviews focused on their expectations of therapy outcomes, their understanding of change, and their evaluation of individual and relational therapy outcomes. We followed a grounded theory approach to data analysis. Analyses showed that therapists, family judges, and clients hold different expectations and theories regarding therapeutic change. Findings are discussed based on existing research on clients’ and therapists’ ideas about change. Implications for future research and practice are presented.
Exhaled nitric oxide decreases during exercise in non‐asthmatic children
Authors: Evjenth Bjørg , Hansen Tonje E. , Holt Jan
Published: April 2012

Introduction:  Exhaled nitric oxide (FENO) measurements are recommended to be performed before spirometry and exercise challenge tests because forced breathing might influence FENO values. Information on the effect of exercise on FENO is lacking in non‐asthmatic children.

Aim:  To investigate the effect on FENO of a standardized exercise challenge test on a treadmill in non‐asthmatic children with and without allergic rhinoconjunctivitis (AR) symptoms.

Methods:  From the case‐control study ‘Asthma and allergy among school children in Nordland’, 330 non‐asthmatic pupils age 8–16 years were enrolled. FENO was measured at baseline and at 1 min and 30 min after exercise challenge test by the single breath technique with EcoMedics Exhalazer® (Eco Physics, Duernten, Switzerland).

Results:  Pair‐wise comparison of FENO from baseline demonstrated a highly significant reduction in FENO post‐exercise for all children at 1 min (27.4%) and at 30 min (16.1%) (P < 0.001). The AR group had a significantly higher decline in FENO value at 1 min post‐exercise compared to the non‐AR group, 4.2 parts per billion (ppb) vs 2.6 ppb (P < 0.001). Decline in FENO immediately post‐exercise was more significant if baseline FENO was ≥ 20 ppb; mean reduction 9.9 (95% CI: 8.7–11.4) ppb.

Conclusion:  FENO is reduced by 27.4% immediately after a standardized treadmill exercise test in non‐asthmatic children. Pupils reporting AR symptoms demonstrate a larger decline in FENO value at 1 min post‐exercise compared to pupils without AR symptoms. These findings confirm that children should refrain from physical activity before FENO measurement.

Please cite this paper as: Evjenth B, Hansen TE and Holt J. Exhaled nitric oxide decreases during exercise in non‐asthmatic children. Clin Respir J 2013; 7: 121–127.
Vigilance of alternatives to blood components
Authors: CROMEY CATHERINE , THOMAS DAFYDD
Published: April 2012

To help minimize the risks of blood component transfusion various techniques have been developed. These novel therapies have focused on the use of autologous transfusion techniques and the use of pharmacologic agents to reduce bleeding and therefore reduce transfusion requirements. These have the potential to drastically reduce transfusion requirements and benefit patients enormously. However, it is important that these therapies are not considered risk‐free and auditing their safety and monitoring their use is essential. There is a need to develop a hemovigilance reporting system to identify and quantify adverse effects associated with the use of these transfusion alternatives.
Cumulative sum method in nonzero fixed action level setup correction strategy: An application of statistical process control for targeted prostate radiotherapy
Authors: Ung N. M. , Wee L.
Published: April 2012

Purpose:

This study aims to incorporate a statistical process control tool, the cumulative sum (CUSUM) method, in the nonzero fixed action level setup correction strategy for the detection and correction of systematic shifts in prostate position during prostate image‐guided radiotherapy.

Methods:

A daily nonzero action level setup correction strategy using CUSUM chart was proposed and tested retrospectively on 34 nonrandomized patients with prostate‐implanted fiducial markersin situ plus daily localization via stereoscopic electronic portal imaging. A cumulative error index, which monitors a cumulative process index over time, was implemented in parallel with the localization offsets of the prostate. A value of this index exceeding a decision interval H indicated that a systematic change in the mean value of localization had occurred. When a value of the index exceeding H was recorded, the magnitude of the systematic shift was estimated and the subsequent prescribed offsets were corrected to account for the new setup positions. With the new protocol, the authors produced simulated treatment histories in which the detection of systematic shifts and the frequency of localization offset exceeding action level were evaluated. The protocol was examined against three levels of mean systematic shifts of localization for detection (μ1) of 3, 5, and 7 mm.

Results:

The overall rates of detection of systematic shifts using this algorithm were relatively high. The level μ1 = 3 mm resulted in the highest rate of detection of systematic offset change, in 42% of the charts. For larger values of μ1, the overall detection numbers fell to 18% and 12% of the charts for μ1 = 5 and 7 mm, respectively. The mean magnitude of change in systematic offset at time of detection was 3.1, 4.4, and 5.2 mm for μ1 = 3, 5, and 7 mm, respectively. By adapting the setup position for any change in systematic localization offset over a course of treatment using the new protocol, it has been shown that the frequency of localization offsets exceeding action levels was reduced. For the optimal choice of intervention levels for correction and μ1, the number of localization offsets exceeding action levels has been reduced by approximately half.

Conclusions:

The nonzero fixed action level setup correction strategy incorporating CUSUM charts has been shown to provide an objective method for (i) detecting a systematic shift of a patient localization offset, (ii) quantifying the magnitude of a systematic change based on previous observations, and (iii) correcting the prescribed offset by accounting for the systematic shift(s) in patient setup position.
Human papillomavirus vaccine practices in the USA: do primary care providers use sexual history and cervical cancer screening results to make HPV vaccine recommendations?: Table 1
Authors: Kepka Deanna , Berkowitz Zahava , Yabroff K Robin , Roland Katherine , Saraiya Mona
Published: April 2012

Objectives

Guidelines recommend against the use of Papanicolaou (Pap) or human papillomavirus (HPV) testing when determining eligibility for the HPV vaccine. Optimally, the HPV vaccine should be administered before sexual initiation. Guidelines recommend that age-eligible women with past exposure to HPV should still be vaccinated. Little is known about how primary care providers (PCPs) use sexual history and HPV and Pap tests in their HPV vaccine recommendations.

Methods

Data from the 2007 Cervical Cancer Screening Supplement (CCSS) administered with the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) were used to assess HPV vaccination recommendations. The CCSS investigates cervical cancer screening practices, HPV testing and HPV vaccine recommendations among PCPs. A summary measure of compliance with guidelines was defined as rarely or never using the number of sexual partners and HPV tests and Pap tests to determine vaccine receipt. A total of 421 PCPs completed the CCSS in 2007.

Results

Among NAMCS and NHAMCS providers who recommend the HPV vaccine, only 53% (95% CI 42% to 63%) reported making guideline-consistent recommendations. The majority reported sometimes to always recommending the HPV vaccine to women with a history of an abnormal Pap result (85%; 95% CI 75% to 91%) and a positive HPV test (79%; 95% CI 70% to 86%).

Conclusions

A large proportion of providers report practices that are inconsistent with guidelines. Providers may also be recommending the vaccine to women who may receive little benefit from the vaccine. Provider and system-level efforts to improve guideline-consistent practices are needed.
RESONANCE RESPONSE OF A SIMPLY SUPPORTED ROTOR-MAGNETIC BEARING SYSTEM BY HARMONIC BALANCE
Authors: LEUNG A. Y. T. , GUO ZHONGJIN
Published: April 2012

Both the primary and superharmonic resonance responses of a rigid rotor supported by active magnetic bearings are investigated by means of the total harmonic balance method that does not linearize the nonlinear terms so that all solution branches can be studied. Two sets of second order ordinary differential equations governing the modulation of the amplitudes of vibration in the two orthogonal directions normal to the shaft axis are derived. Primary resonance is considered by six equations and superharmonic by eight equations. These equations are solved using the polynomial homotopy continuation technique to obtain all the steady state solutions whose stability is determined by the eigenvalues of the Jacobian matrix. It is found that different shapes of frequency-response and forcing amplitude-response curves can exist. Multiple-valued solutions, jump phenomenon, saddle-node, pitchfork and Hopf bifurcations are observed analytically and verified numerically. The new contributions include the foolproof multiple solutions of the strongly nonlinear system by means of the total harmonic balance. Some predicted frequency varying amplitudes could not be obtained by the multiple scales method.
ON UNIQUENESS FOR TIME HARMONIC ANISOTROPIC MAXWELL'S EQUATIONS WITH PIECEWISE REGULAR COEFFICIENTS
Authors: BALL JOHN M. , CAPDEBOSCQ YVES , TSERING-XIAO BASANG
Published: April 2012

We are interested in the uniqueness of solutions to Maxwell's equations when the magnetic permeability μ and the permittivity ε are symmetric positive definite matrix-valued functions in ℝ3. We show that a unique continuation result for globally W1, ∞ coefficients in a smooth, bounded domain, allows one to prove that the solution is unique in the case of coefficients which are piecewise W1, ∞ with respect to a suitable countable collection of subdomains with C0 boundaries. Such suitable collections include any bounded finite collection. The proof relies on a general argument, not specific to Maxwell's equations. This result is then extended to the case when within these subdomains the permeability and permittivity are only L∞ in sets of small measure.
IMPROVING CONVERGENCE IN NUMERICAL ANALYSIS USING OBSERVERS — THE WAVE-LIKE EQUATION CASE
Authors: CHAPELLE D. , CÎNDEA N. , MOIREAU P.
Published: April 2012

We propose an observer-based approach to circumvent the issue of unbounded approximation errors — with respect to the length of the time window considered — in the discretization of wave-like equations in bounded domains, which covers the cases of the wave equation per se and of linear elasticity as well as beam, plate and shell formulations, and so on. Namely, taking advantage of some measurements available on the system over time, we adopt a strategy inspired from sequential data assimilation and by which the discrete system is dynamically corrected using the discrepancy between the solution and the measurements. In addition to the classical cornerstones of numerical analysis made up by stability and consistency, we are thus led to incorporating a third crucial requirement pertaining to observability — to be preserved through discretization. The latter property warrants exponential stability for the corrected dynamics, hence provides bounded approximation errors over time. Special care is needed to establish the required observability at the discrete level, in particular due to the fact that we focus on an original observer method adapted to measurements of the main variable, whereas measurements of the time-derivative — admissible, of course, albeit less frequent in practical systems — lead to a stability analysis in which existing results can be more directly applied. We also provide some detailed application examples with several such wave-like equations, and the corresponding numerical assessments illustrate the performance of our approach.
A successful model: 30 years of the Lincolnshire Chalk model
Authors: Hutchinson M. J. , Ingram R. G. S. , Grout M. W. , Hayes P. J.
Published: April 2012

The Lincolnshire Chalk aquifer on the east coast of England is used regionally for water supply. However, groundwater abstraction can exceed recharge during times of drought, resulting in saline intrusion. Following hydrogeological investigations in the 1970s and 1980s, a regional groundwater model was developed to underpin the tactical management of the aquifer. Although it is a coarse, single-layer, constant-density model, routine regulatory use of the model since 1988 has enabled a sustainable level of groundwater abstraction to be reached and brought saline intrusion under control. Abstraction rates have been proactively adjusted to suit prevailing conditions using model forecasts. Forecasts are evaluated against model-based thresholds, set by comparing model output (e.g. aquifer–estuary flux) with observed data (e.g. groundwater salinity). The success of the model in managing groundwater resources is attributed to: field-based hydrogeological investigations informing the model design; collaboration between regulators and abstractors, which has built confidence in the model results; commitment to updating the model; and flexibility in the supply network through conjunctive use of ground and surface water. The model has also been applied for purposes not considered during development and has therefore provided value for money for the UK water industry over a 30 year period.
Catchment-scale water balance modelling in a Carboniferous Limestone aquifer
Authors: Ingram R. G. S. , Stone N. , Carey M. , Smart P.
Published: April 2012

Groundwater models are used to manage water resources in carbonate aquifers throughout the UK. These models often utilize non-linear modifications of equivalent porous media (EPM) assumptions to simulate the observed head-flow relationships. This paper describes the application of similar principles to time-variant water balance modelling of a karstified aquifer: the Carboniferous Limestone in SW England. The non-linear model successfully simulates the large changes in bulk hydraulic conductivity required to adequately model flows from two karstic spring catchments. Model results illustrate that the rate of drainage from the vadose zone is affected by the extent and thickness of soil cover. In a catchment with mixed soil cover, vadose zone drainage is shown not to be significant in sustaining summer low flows at the spring. The performance of the model is limited in some cases: summer storm flows in particular are poorly simulated. The limitations suggest that the true response of the system is dependent on recharge intensity (rate) as well as antecedent water levels and that the EPM assumption of good connection between conduits and the diffuse flow zone is not always valid in this aquifer. This may have implications for groundwater model design in other carbonate aquifers.
The use of groundwater levels and numerical models for the management of a layered, moderate-diffusivity aquifer
Authors: Shepley M. G. , Soley R. W. N.
Published: April 2012

The predictions from a numerical time-variant distributed groundwater model are used to assess the spatial and temporal impacts of groundwater abstraction for an unconfined and layered, moderate diffusivity aquifer; the West Midlands–Worfe Permo-Triassic Sandstone in the UK. These impacts have been determined by comparing a recent actual baseline predictive simulation with simulations where groundwater abstractions are switched off, including a ‘naturalized’ simulation. By reference to the historic simulation, the predictive model results are compared against observed groundwater levels. The predictive simulations demonstrate that observed groundwater levels could be an indicator of groundwater abstraction impacts on surface water flows where widespread stream disconnection has occurred due to high rates of abstraction. This relationship also depends on the aquifer hydraulic characteristics, the interaction between groundwater levels and the surface drainage network and other artificial flow influences. Abstraction impacts on groundwater levels are large for the West Midlands–Worfe aquifer, but can be obscured by the climatic recharge signal in observed groundwater level records. This is a consequence of the moderate diffusivity and the main groundwater abstraction development preceding systematic monitoring. The groundwater model can be used to identify which observation boreholes have negligible abstraction impacts; this may be valuable for identifying groundwater level records that are useful for climate change analysis.
Start, development and status of the regulator-led national groundwater resources modelling programme in England and Wales
Authors: Whiteman M. I. , Seymour K. J. , Van Wonderen J. J. , Maginness C. H. , Hulme P. J. , Grout M. W. , Farrell R. P.
Published: April 2012

Over the last 10 years there has been a unique regulator-led programme involving extensive development of regional groundwater models across England and Wales for water resources purposes by the Environment Agency for England and Wales. Eight regionally managed programmes are underpinned by a framework, which has allowed a coordinated national approach. The main uses of the models are for catchment abstraction management and licensing. Models have also assisted in monitoring network design, investigating groundwater quality and implementing groundwater source protection zones. A five-yearly review of the programmes recognized the importance of benefit realization and stakeholder involvement as well as technical good practice. The programme already delivered provides a solid foundation for supporting the management decisions required in areas such as climate change mitigation and integrated catchment management using appropriate tools at a time of rapid organization change and financial uncertainty.
How to get your model results used: a guide to stakeholder engagement
Authors: Hughes A. G. , Van Wonderen J. J. , Rees J. G. , Seymour K. J. , Manful D. , Karl H.
Published: April 2012

The usage of modelling results by their intended audience is an important aspect of undertaking any project. However, providing the appropriate results in the correct way to key stakeholders is not a straightforward task. Fortunately, there is a growing body of work about approaching the engagement of stakeholders in a way to maximize the impact of modelling results. Using the lessons learnt from a number of recent workshops, including those conducted for the benefits realization process undertaken for the Environment Agency of England and Wales, suggestions for best practice are presented and their relative merits discussed. Best practice for getting groundwater modelling results used by their intended audience is proposed.
Advances in modelling groundwater behaviour in Chalk catchments
Authors: Butler A. P. , Hughes A. G. , Jackson C. R. , Ireson A. M. , Parker S. J. , Wheater H. S. , Peach D. W.
Published: April 2012

Groundwater in Chalk catchments is a major resource that also helps support internationally important habitats and ecosystems. Its dual porosity and dual permeability properties, coupled with large-scale structural features (such as hard rock layers and marls), produce a highly complex hydrogeological system. Recent impacts from groundwater flooding as well as vulnerability to drought have raised questions over the ability of traditional approaches to model these aquifers. Current work on near-surface hydrological processes has highlighted the importance of the soil and weathered zone for controlling recharge rates. In addition, karst-like features, sedimentary deposits and valley bottom processes govern stream–aquifer interaction and present a challenge in their representation in any modelling system. Methods that have, and are being, developed to incorporate these features, and their use in modelling Chalk catchments, are described. These are required in order to address major challenges, such as groundwater flooding and drought impacts, both of which could become more frequent and intense as a result of climate change.
Shellac and Hydroxyapatitte Coatings on Titanium Niobium and AISI 316L Steel Surfaces Produced by Dip-Coating
Authors: Gomes Bruna F. , Picon Carlos A. , Fernandes Frederico A. , Rodrigues Filho Ubirajara P. , Tremiliosi-Filho Germano
Published: April 2012

Shellac is a natural resin used for the preservation of fruits, bones and as a coating on drugs. The hydroxyapatite (HA), which is naturally found in human bones, is used as filler to substitute amputated bone or as a coating for prosthetics, promoting bone growth in implants of prostheses. The objective of this work is to immobilize HA from an alcoholic solution of shellac on plates of titanium, niobium and AISI 316L steel using the simple dip-coating method. The corrosion resistance of the uncoated films is compared with ones coated with shellac and shellac plus HA. The deterioration of the film composed of shellac with hydroxyapatite in saline solution follows the ascending order: AISI 316L steel, titanium, niobium. The elemental analysis of the shellac showed that it mainly consists of the elements C, H, N and O. We used the FT-IR spectrum to characterize the shellac and HA.
Corrosion Protection of Aluminum Alloys by Methoxy-Silanes(SAM)/Polyaniline Double Films
Authors: Silva Daiane P. , Santis Neves Rodrigo , Jesus Motheo Artur
Published: April 2012

The development of alternative methods for aluminum alloys corrosion protection is as an important object of study in electrochemistry and materials engineering, due to economic and environmental reasons. In this context, this work presents a study of the electrochemical behavior of aluminum alloys (AA1050 and AA2024) coated with self-assembled monolayers (octadecyl- and propyl-trimethox-silane)-polyaniline double films by using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results have showed that both the double films present protective behavior. However, the double film with octadecyl-trimethoxy-silane is more stable and effective when the samples are exposed to the corroding media for a longer period.
Study of Parabanic Acid and a Derived Dithiocarbamate as Corrosion Inhibitors of Bronze
Authors: Figueiredo João C. , Cunha Igor T.
Published: April 2012

Corrosion inhibitors are compounds that reduce or eliminate corrosion. The ability of a molecule to act as corrosion inhibitor can be attributed to the presence of S, N and O atoms in the molecule. Best inhibition efficiency is attributed to compounds with S atoms. This paper reports the study of parabanic acid and a derived dithiocarbamate compound as corrosion inhibitors of a bronze alloy TM 23. The compounds were characterized by elemental analysis and infrared absorption spectroscopy. Inhibition efficiency was studied by means of quantum chemical calculations and polarization curves. Polarization curves were recorded with different concentrations of inhibitors in HCl 10-1 mol.L-1. The obtained results showed that both compounds are corrosion inhibitors and the dithiocarbamate compound is the most efficient inhibitor. The efficiency of the dithiocarbamate compound was attributed to the presence of S atoms in its structure.
Electrochemical Assessment of the Effects of Therapeutic Ultrasound on Rutin
Authors: Saling Caroline , Bianchetti Paula , Tassinary João A. , Ethur Eduardo M. , Stülp Simone
Published: April 2012

This work aims at assessing electrochemically the effect of therapeutic ultrasound (US) on a system containing rutin. In this study, were used 1 MHz and 3 MHz frequencies, and 0.8 W cm-2 intensity in the US transducer. The cyclic voltammetry was performed with a one-compartment electrochemical cell, a platinum plate was the working electrode, a platinum wire was the auxiliary electrode, and a silver wire coated with silver chloride was the quasi-reference electrode. The scan rate was 10 mV s-1 and the applied potential range was - 400 mV to + 1400 mV. All experiments were performed in triplicate. The results show that rutin was oxidized in the presence of US, preferentially at 3 MHz.
Electrochemical Determination of the Real Area of Nanocrystalline Boron Doped Diamond
Authors: Saito Eduardo , Souza Fernando A. , Azevedo Adriana F. , Ferreira Neidenei G. , Baldan Mauricio R.
Published: April 2012

The present work is devoted to evaluate the area of samples of nanocrystalline Boron Doped Diamond grown with different dopant solutions. The samples were characterized by Scanning Electron Microscopy (SEM) and Atomic Force Micrsocopy (AFM) and electrochemically by Differential-capacitance (Mott-Schottky plots) and Cyclic Voltammetry. By SEM was possible detect "cauli flower" morphology and by AFM was possible to quantify the roughness of the samples. We evaluate the dopant level by Raman spectroscopy and by Mott Schottky plots. The electrochemical roughness measured by AFM was compared with the roughness determined Cyclic Voltammetry.
Copper Photoelectrodeposition onto Boron Doped Micro and Ultra-Nanocrystalline Diamond Electrodes Applied to Nitrate Electroreduction
Authors: Couto Andrea B. , Baldan Mauricio R. , Ferreira Neidenei G.
Published: April 2012

The influence of the boron doped micro and ultra-nanocrystalline diamond (BDD and BDUND) morphologies in the copper photoelectrodeposition was investigated. Copper particles were deposited in the potentiostact mode and under UV irradiation for both electrodes. For BDD, the copper deposits presented high density and uniformity all over the crystal faces. This behavior may be explained by its semiconductor character that promoted additional photogenerated electrons enhancing the copper reduction reaction. Otherwise, for BDUND the copper particles were randomly located with low density. Concerning the nitrate reduction process, Cu/BDD presented a better response and reproducibility compared to those for the Cu/BDUND electrode.
Formation of Silver Chloride Nanocrystals as a Corrosion Product of Silver in H2SO4 Solution
Authors: Picon Carlos A. , Fernandes Frederico A. , Machado Sergio A. , Tremiliosi-Filho Germano , Casteletti Luiz C.
Published: April 2012

The purpose of this study is to characterize the corrosion product on the surface of silver, employing H2SO4 (0.5M) as electrolyte. The electrochemical parameters, Ecor, Icor, Vcor and Rp were obtained after analyzing the potentiodynamic polarization curve in which two peaks were observed. The smallest (passive region) is attributed to the Cl- traces from the reference electrode, with micro-cracks. The second peak (in the transpassivation region) corresponds to the polarization curve of silver in H2SO4 without contaminants. SEM images and EDS analysis reveal images of a surface layer on silver, consisting of structures containing sulfur, oxygen, silver and chloride, as the corrosion product. On this layer silver sulfate crystals were observed, which occurs during the formation of silver chloride nanocrystals with different morphologies, when chloride ions were added to the electrolyte medium.
Structural and Electrochemical Properties of NDND Films Grown in a HFCVD System
Authors: Azevedo Adriana F. , Baldan Mauricio R. , Ferreira Neidenei G.
Published: April 2012

Nitrogenated nanocrystalline diamond films were grown from hot filament reactor in CH4-Ar-H2-N2 gas mixtures. They were characterized using scanning electronic microscopy and Raman spectroscopy. Significant changes on the film surface morphologies and Raman spectra were observed due to N2 addition. Their electrochemical properties were studied by cyclic voltammetry. The electrodes behavior showed to be controlled by the degree on nitrogenation. With the increase of the nitrogen content in the reaction gas mixture (from 2 to 20 vol.%), the reversibility of reactions in the Fe(CN)63-/4- redox system in the films increased. In respect of the electrodes grown in experimental conditions described in this work, they have the properties very close to those grown in microwave plasma reactor.
Characterization and Optical Properties of ZnSe Thin Films Obtained by Electrodeosition Technique
Authors: Gromboni Murilo F. , Kastein Thiago C. , Matos Roberto , Mascaro Lucia H.
Published: April 2012

In this work, results on the preparation and characterization of ZnSe thin films obtained by electrodeposition are presented. Voltammetric curves were recorded in order to characterize the electrochemical behavior of the Zn(II)+Se(IV) system. Thin films were deposited potentiostatically from an unstirred, deareated aqueous solution onto Au or ITO glass substrates. The deposits morphology and physics properties were characterised by FEG, UV-Vis and DRX.
Determination of Dopamine Employing Enzymatic Biosensor Based on Multi-Wall Carbon Nanotube and Crude Extract of Zucchini
Authors: Ribeiro Fabíola A. , Tarley César R. , Pereira Arnaldo C.
Published: April 2012

Enzymatic biosensor is proposed for the determination of dopamine, using carbon nanotube paste modified with peroxidase that was obtained from the crude extract of zucchini (Curcubita pepo). Analytical parameters influencing the biosensor performance as the amount enzyme, hydrogen peroxide concentration, pH and type of buffer, were evaluated. The best biosensor response was obtained using 1.10 U mg-1 enzyme in the carbon nanotube paste, 0.1M phosphate buffer (pH = 6.0) containing 50 µM H2O2. The response linear relationship for dopamine was achieved from 60 to 1700 µmol L-1 with sensitivity of 21 x nA/µmol L-1 and detection limit of 5.9 x 10-6 mol L-1 under optimized experimental conditions.
Electrochemical Behavior in Na2SO4 of Nanoporous Oxide Films Previously Formed on AISI 304 by Electrocoloring
Authors: Lubini Marcieli , Vieceli Taveira Luciano , Weber Cristina R. , Dick Luis F.
Published: April 2012

Thick nanoporous oxide films exhibiting interference colors were grown on AISI 304L stainless steel by triangular current scan method in 5 M H2SO4 + 2.5 M H2CrO4 using different electrolysis times. The nanocrystalline spinel oxide films thus obtained were electrochemically characterized by cyclic voltammetry at 1 mV•s-1 in 0.5 M Na2SO4. Strong anodic peaks are observed at the potential region where the transpassive peak of stainless steels is expected. Such behavior evidences not only the large active surface area of the films, but also that the cationic species are not fully oxidized. The effect of polarizing in 0.5 M Na2SO4 to a potential in the transpassive region on the morphology and the composition of these films was investigated.
Electrochemical Characteristics of Poly(vinyl pyrrolidone) (PVP) and Poly(vinyl alcohol) (PVA) on Single-Crystal Pt Surfaces in Acidic Medium
Authors: Gasparotto Luiz H. , Gomes Janaina F. , Tremiliosi-Filho Germano
Published: April 2012

In the present paper we investigated the electrochemical behaviors of poly(vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) on Pt (111), (100) and (110) electrodes. Both polymers hampered the characteristic hydrogen UPD and anion adsorption/desorption on all investigated surfaces, with the processes on Pt(110) being the most affected by their presence. Several oxidation processes appeared in the positive potential sweep and the Pt(111) was found to be the most active for the oxidation processes.
Ultratrace Determination of the Antiretroviral Drug Lamivudine in Diluted Alkaline Electrolyte by Adsorptive Stripping Voltammetry
Authors: Farias Percio Augusto M. , Castro Arnaldo A. , Cordoves Ana Isa P.
Published: April 2012

This paper describes a stripping method for the determination of lamivudine at the submicromolar concentration level. This method is based on controlled adsorptive accumulation of lamivudine at the thin-film mercury electrode followed by a linear cyclic scan voltammetry measurement of the surface species. The response of lamivudine is linear over the concentration range from 0.01 - 0.14 ppm. When there was an accumulation time of 4 minutes, the detection limit was found to be 0.13 ppb (5.7 x 10-10 mol L-1). More convenient methods to measure the lamivudine in the presence of the didanosine, acyclovir, nevirapine, nelfinavir, efavirenz and zidovudine were also investigated in this experiment. The utility of the method is demonstrated by the presence of lamivudine together with ATP or DNA.
Electrochemical Behavior of the Antibiotic Minocycline and its Voltammetric Determination in Pharmaceutical Formulations at Carbon Paste Electrode
Authors: Souza Michel Rafael S. , Aragão Débora M. , Santos RenÊ Humberto T. , Garcia Carlos Alexandre B. , Alves José Patrocínio H. , Arguelho Maria Lara P.
Published: April 2012

An analytical method for the determination of the drug minocycline in pharmaceutical formulations using differential pulse voltammetry was developed. Voltammetric analysis of minocycline using a carbon paste electrode revealed a well-defined peak at 0.40 V (vs. Ag/AgCl), corresponding to the oxidation of minocycline at pH 4.0. The electrodic behavior indicated that the oxidation process was reversible, and that it was controlled by diffusion. After the optimization of the experimental conditions, calibration curves were obtained in the linear concentration range from 1.0 x 10-6 to 2.3 x 10-5 mol L-1 resulting in a detection limit of 7.0 x 10-7 mol L-1 and the quantification limit of 2.2 x 10-6 mol L-1. In addition to advantages such as high selectivity and sensitivity, the method developed could be used for the analysis of pharmaceutical formulations containing minocycline without any need for prior sample treatment, an important consideration in routine analysis laboratories.
Preparation of Ni/Carbon Hybrids by Hydrothermal Carbonization and Thermal Treatment for Application as Supports for PtRu/C Electrocatalysts
Authors: Tusi Marcelo M. , Polanco Nataly S. , Brandalise Michele , Ribeiro Vilmaria A. , Correa Olandir V. , Villalba Juan C. , Anaissi Fauze J. , Neto Almir O. , Spinacé Estevam V.
Published: April 2012

Ni/Carbon hybrids were prepared by hydrothermal carbonization at 200 ºC for 48 h using glucose as carbon source, NiCl2.6H2O as oxidizing agent and catalyst of the carbonization process. The materials were prepared in the absence and in the presence of cetyltrimetylammoniun bromide (CTAB) using an CTAB:glucose molar ratios of 1:10. The obtained carbonaceous materials were further treated at 900 ºC under Argon and PtRu nanoparticles were deposited on these materials using an alcohol reduction process. The resulting PtRu/C electrocatalysts were characterized by EDX, thermogravimetrics analysis, X-ray diffraction and transmission electron microscopy and they were tested for methanol electro-oxidation using chronoamperometry. The PtRu/C electrocatalyst prepared using as support Ni/Carbon with CTAB showed superior performance for methanol electro-oxidation.
Eletrochemical Study of the Interaction between Humic Acids Extracted from Soil and the Pb2+ Ion in Aqueous Solution
Authors: Polli Vania Regina G. , Vendrame Zilda B. , Santanna Maria Alice , Gomes Felipe P.
Published: April 2012

The humic acids present in the soil represent the main form of soil organic carbon and are actively involved in the accumulation, transformation and transport of ionic species in the environment. The interaction between the lead ion and the humic acids extracted from superficial soil from Pains (rural area) and Camobi (urban area) of Santa Maria - RS, was investigated in aqueous solution. The study of the humic acids solutions was done employing potentiometric and conductometric titration without and with the presence of the metallic ion at different concentrations. The results have shown displacements in the titration curves of humic acids with the addition of the metallic ion (in comparison with the analogous one without the ion) indicating the existence of interaction between humic acids and the Pb2+ ion in aqueous solution with formation of complexes.
Development of Electrochemical Method for Voltammetric Analysis of Tetradifon on Glassy Carbon Electrode
Authors: Aleixo Herbert , Okumura Leonardo L.
Published: April 2012

The electrochemical determination of the pesticide Tetradifon (TDF) on glassy carbon electrode can be proposed as a faster and cheaper alternative compared to chromatographic methods commonly used in this analysis. The methodology was developed based on the measurement of electrical currents generated by redox processes of the analyte dispersed in a supporting electrolyte solution composed of a mixture of 40% dimethylformamide (DMF), 30% methanol, and 30% NaOH 0.3 mol L-1. Two electroanalytical techniques were employed: the cyclic voltammetry for qualitative studies of the redox processes of the compound and the differential pulse voltammetry that enabled the determination of TDF independently of the presence of a vegetable matrix, specifically Brazilian green bell pepper, culture in which the pesticide is widely used.
Neodymium(III) PVC Membrane Electrodchemical Sensor Based on N‐benzoylethylidene‐2‐aminobenzylamine
Authors: Zamani Hassan Ali , Zaferoni Mojdeh , Meghdadi Soraia
Published: April 2012

The N‐benzoylethylidene‐2‐aminobenzylamine (BEA) was used as a suitable ionophore in construction of neodymium ion selective electrode. The electrode with composition of 30% PVC, 58% solvent mediator (NB), 2% ionophore (BEA) and 10% anionic additive (OA) shows the best potentiometric response characteristics. The Nd3+ sensor exhibits a Nernstian slope of 21.2 ± 0.2 mV decade-1 over the concentration range of 1.0 × 10-6 to 1.0 × 10-2 mol L-1, and a detection limit of 6.3 × 10-7 mol L-1 of Nd3+ ions. The potentiometric response of the sensor is independent of the solution pH in the range of 2.4–8.5. It has a very short response time, in the whole concentration range (~7 s), and can be used for at least eight weeks. The proposed sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The Nd3+ sensor was successfully applied as an indicator electrode in the potentiometric titration of Nd3+ ions with EDTA. The electrode was also employed for the determination of the fluoride ion in two mouth wash preparations.
Spider-Ant Associations: An Updated Review of Myrmecomorphy, Myrmecophily, and Myrmecophagy in Spiders
Authors: Cushing Paula E.
Published: April 2012

This paper provides a summary of the extensive theoretical and empirical work that has been carried out in recent years testing the adaptational significance of various spider-ant associations. Hundreds of species of spiders have evolved close relationships with ants and can be classified as myrmecomorphs, myrmecophiles, or myrmecophages. Myrmecomorphs are Batesian mimics. Their close morphological and behavioral resemblance to ants confers strong survival advantages against visually hunting predators. Some species of spiders have become integrated into the ant society as myrmecophiles or symbionts. These spider myrmecophiles gain protection against their own predators, live in an environment with a stable climate, and are typically surrounded by abundant food resources. The adaptations by which this integration is made possible are poorly known, although it is hypothesized that most spider myrmecophiles are chemical mimics and some are even phoretic on their hosts. The third type of spider-ant association discussed is myrmecophagy—or predatory specialization on ants. A table of known spider myrmecophages is provided as is information on their biology and hunting strategies. Myrmecophagy provides these predators with an essentially unlimited food supply and may even confer other protections to the spiders.
Screening of Industrial Wastewaters as Feedstock for the Microbial Production of Oils for Biodiesel Production and High-Quality Pigments
Authors: Schneider Teresa , Graeff-Hönninger Simone , French William Todd , Hernandez Rafael , Claupein Wilhelm , Holmes William E. , Merkt Nikolaus
Published: April 2012

The production of biodiesel has notably increased over the past decade. Currently, plant oil is the main feedstock for biodiesel production, but, due to concerns related to the competition with food production, alternative oil feedstocks have to be found. Oleaginous yeasts are known to produce high amounts of lipids, but no integrated process from microbial fermentation to final biodiesel production has reached commercial realization yet due to economic constraints. Therefore, growth and lipid production of red yeastRhodotorula glutiniswas tested on low-cost substrates, namely, wastewaters from potato, fruit juice, and lettuce processing. Additionally, the production of carotenoids as high-value by-products was examined. All evaluated wastewaters met the general criteria for microbial lipid production. However, no significant increase in lipid content was observed, probably due to lack of available carbon in wastewaters from fruit juice and lettuce processing, and excess of available nitrogen in potato processing wastewater, respectively. During growth on wastewaters from fruit juice and lettuce processing the carotenoid content increased significantly in the first 48 hours. The relations between carbon content, nitrogen content, and carotenoid production need to be further assessed. For economic viability, lipid and carotenoid production needs to be increased significantly. The screening of feedstocks should be extended to other wastewaters.