bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antecedents and consequences of acculturation preferences of non‐indigenous Chileans in relation to an indigenous minority: longitudinal survey evidence
Authors: Zagefka Hanna , Brown Rupert , González Roberto 
Published: June 2008

AbstractTwo longitudinal survey studies were conducted with non‐indigenous majority Chilean participants (Ns = 755 cross‐sectional, 198 longitudinal in study 1; 390 cross‐sectional, 333 longitudinal in study 2). In contrast to most previous research, the longitudinal design allowed to test directly the hypothesised causal direction of effects. There were two broad research questions. Firstly, what is the relationship between acculturation preferences of non‐indigenous majority members and negative affect towards the indigenous Mapuche? More specifically, does a preference for integration lead to less negative affect than a preference for assimilation, separation or marginalisation? Related to this, do the dimensions of culture maintenance and contact taken singly predict negative affect and/or vice versa? Secondly, does knowledge about the Mapuche causally and indirectly influence acculturation preferences, partially mediated by sympathy with the Mapuche? Results confirmed that knowledge influenced acculturation preferences, and that sympathy was a partial mediator. Acculturation preferences, in turn, influenced negative affect. The contact dimension underlying the categorical acculturation strategies was a predictor of outcomes, while the culture maintenance dimension was not. Implications of the findings are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
A Selective Film Based on Poly(3‐octylthiophene) Doped with Dihydroxyanthraquinone Sulfonate
Authors: Tamer Uğur , Ertaş Nusret , Ergüner Övgü , Gündoğdu Yusuf 
Published: June 2008

AbstractA stable film of poly(3‐octylthiophene)–dihydroxyanthraquinone sulfonate has been synthesized electrochemically in non‐aqueous solution. The incorporation of dihydroxyanthraquinone sulfonate as an anionic complexing ligand into poly(3‐octylthiophene) film during electropolymerization was achieved and copper ions were accumulated by reduction on the electrode surface. The presence of dihydroxyanthraquinone sulfonate during the electrochemical polymerization of 3‐octylthiophene is shown to impact the sensitivity and the stability of the organic conducting film electrode response. The electroanalysis of copper(II) ions using conducting polymer electrode was achieved by differential pulse anodic stripping voltammetry with remarkable selectivity. The analytical performance was evaluated and linear calibration graphs were obtained in the concentration range of 50–400 ng mL−1 copper(II) ion for 240 seconds accumulation time and the limit of detection was found to be 7.8 ng mL−1. To check the selectivity of the proposed stripping voltammetric method for copper(II) ion, various metal ions as potential interferents were tested. The developed method was applied to copper(II) determination in certified reference material, NWRI‐TMDA‐61, trace elements in fortified water.
Electrochemical Polymerization of 3,4‐Ethylenedioxythiophene from Aqueous Solution Containing Hydroxypropyl‐β‐cyclodextrin and the Electrocatalytic Behavior of Modified Electrode Towards Oxidation of Sulfur Oxoanions and Nitrite
Authors: Vasantha V. S. , Thangamuthu R. , Chen Shen‐Ming 
Published: June 2008

AbstractPoly(3,4‐ethylenedioxythiophene) (PEDOT) film was prepared on glassy carbon electrode from 0.1 M LiClO4 aqueous solution containing 3,4‐ethylenedioxythiophene (EDOT) monomer and hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD), by multiple scan cyclic voltammetry. The effect of oxidation potentials on electropolymerization of EDOT was examined by chronoamperometry and cyclic voltammetric techniques. The results of potentiostatic experiments show that optimum potential range to obtain compact stable film was 0.9 to 1.05 V (vs. Ag/AgCl). At higher positive potential, i.e. above 1.05 V, polymer growth was hindered by passivation effect. The PEDOT film exhibited a strong absorption at 550 nm in the UV‐vis region and also a multicolor electrochromism in different buffer solutions (sky blue‐purple red). Cyclic voltammetric features of PEDOT‐coated electrode in pure supporting electrolyte suggested that charge transfer of the film resembles that of surface‐confined redox species. Finally, the electrocatalytic behavior of PEDOT‐modified electrode was tested towards oxidation of sulfur oxoanions and nitrite using cyclic voltammetry.
Heterogeneous Membrane and Coated Wire Type Electrode with Chitosan as Ionophore in the Potentiometric Determination of Glutamate: Comparative Study
Authors: Md Isa Illyas , Ab Ghani Sulaiman 
Published: June 2008

AbstractThis study reports on two types of glutamate sensors based on chitosan, i) heterogeneous membrane and ii) coated wire (CWE). The linearity ranges are: i) membrane, 1.0×10−5 to 1.0×10−1 M and ii) CWE, 1.0×10−5 to 1.0×10−3 M. The LODs, and pH ranges are i) membrane, 5.0×10−6 M and 4–8 and ii) CWE, 1.0×10−5 M and 3–5, respectively. The presence of ionic species normally found in foodstuffs did not interfere in both electrodes. Interference in CWE was minimized by prior dilution of the sample. The CWE was further investigated for on‐line analysis. The material for proposed electrodes was cheaper and environmental friendly. Hence, they were suggested as alternative tools for the analysis of glutamate.
High Sensitive Electrochemical Detection of Sequence‐Specific DNA Using Low Current Voltammetry
Authors: Lin Lingling , Zhou Jianzhang , Zhang Yan , Lin Zhonghua 
Published: June 2008

AbstractIn this article, we report on efforts to construct a high sensitive electrochemical sensor with immobilized sandwich‐type DNA borne ferrocene (Fc) head for sequence‐specific DNA detection using ultramicroelectrode and low current voltammetry. Based on the difference in deformability between the bending rigid complementary DNA double helix and its anomalous flexile mismatches, the fully complementary target can be distinguished from mismatched targets including the single‐base mismatched target. Detection limit estimated as the amount of DNA is observed to be 100 fM via low current voltammetry. The method offers great promise of high sensitivity and selectivity simultaneously for effective gene identification.
Some Properties of Sodium Dodecyl Sulfate Functionalized Multiwalled Carbon Nanotubes Electrode and Its Application on Detection of Dopamine in the Presence of Ascorbic Acid
Authors: Zheng Dan , Ye Jianshan , Zhang Weide 
Published: June 2008

AbstractA sodium dodecyl sulfate (SDS) functionalized multiwalled carbon nanotubes (MWNTs) electrode (SDS/MWNTs) was successfully constructed in this study. The electrochemical property of the SDS/MWNTs electrode has been characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Nyquist plots suggest that the immersion time of SDS affects the resistances of the MWNTs electrodes. The thickness of adsorbed SDS on MWNTs surface is estimated to be 1.23 nm, which is close to the value of SDS monolayer. CV results demonstrate a 5‐fold enhanced response for dopamine (DA) at the SDS/MWNTs electrode compared to the bare MWNTs one. DPV results illustrate that DA can be selectively determined in the presence of high concentration ascorbic acid (AA) with a linear range from 20 μM to 0.20 mM and a sensitivity of 0.024 μA μM−1 at the SDS/MWNTs electrode.
Protocol for Extraction and Determination of Cr(VI) in Solid Materials with a High Cr(III)/Cr(VI) Ratio Using EDDS as a Leaching Agent for Cr(VI) and a Masking Agent for Cr(III)
Authors: Grabarczyk Malgorzata 
Published: June 2008

AbstractA sensitive and selective protocol for the extraction of all forms of Cr(VI) from solid materials followed by determination by catalytic adsorptive stripping voltammetry has been elaborated. Cr(VI) was leached to a solution with 0.2 mol L−1 (NH4)2SO4/NH4OH+0.1 mol L−1 EDDS (pH 9.5) and simultaneously Cr(III) was transferred to a nonactive electrochemical complex with EDDS. The method allows for Cr(VI) determination in solid samples containing even a 1000–2000 fold excess of extractable Cr(III) without its noticeable influence. The effects of several experimental variables such as the composition and pH of the extractant, the time and temperature of the solid sample mixing with the extractant were studied. At the optimized conditions more than 95% of total Cr(VI) recoveries from solid samples were achieved. The validation of the proposed procedure was carried out by Cr(VI) determination in certified reference material CRM 019 Ash, spiked and unspiked with Cr(III), and by comparing the obtained results with those obtained using other common extraction procedures.
Flow Injection Analysis of Iodate Reduction on PEDOT Modified Electrode
Authors: Balamurugan A. , Chen Shen‐Ming 
Published: June 2008

AbstractPoly‐(3,4‐ethylenedioxythiophene) (PEDOT) films were electrodeposited by cyclic voltammetry on glassy carbon electrode at different anodic potentials in the range of 1.0–1.5 V (Ag/AgCl) and its electrocatalytic properties towards reduction of iodate were reported. The effect of the pH of the solution on the response of PEDOT electrode towards iodate also studied. The modified electrode was employed successfully as an amperometric sensor for iodate in a flow injection apparatus. The repeatability of the method for 14 injections of a μM iodate solution was 7%. Interference from other oxidant anions such as nitrate was not noticeable, whereas bromate, chlorate and nitrite interfere at slight levels.
Components of the Net Current in Differential Pulse Polarography
Authors: Zelić Marina , Jadreško Dijana 
Published: June 2008

AbstractAs the modern (voltammetric) software packages offer ‘resolution’ of each individual net signal in differential pulse polarography (DPP) to its components, an attempt was made to test such a possibility on several model systems. Reversible and nonreversible reduction processes of simple metal ions (Cd2+, Eu3+) were included, together with some examples of the anion induced adsorption (Cd2+‐I− and Pb2+‐Br− systems) under conditions of partly or fully covered electrode surface. Taking into account that so called ‘backward’ current is in fact DC wave, it could be said that one technique is hidden within the other. Consequently, DPP measurements together with following of the ‘backward’ signals could give more information and save the time. ‘Forward’ component offers additional possibilities in data treatment, especially when its relationship to the ‘backward’ current (with respect to the potential and height) is taken into account. Such an approach seems promising, even when applied on a purely qualitative level, because some effects which cannot be observed if only the net signals are followed become obvious when their components are taken into consideration.
Autooxidative Activity of Chlorogenic Acid and Damage to DNA
Authors: Yang Zhou‐sheng , Long Hai‐yan , Zhang Xiao‐yan , Wang Yong 
Published: June 2008

AbstractThe interaction of chlorogenic acid with double‐stranded calf thymus DNA was investigated in solution by cyclic voltammetry at a glassy carbon electrode (GCE). The different working electrodes were prepared by covering solution containing different components onto the surface of GCE. The autooxidative activity of chlorogenic acid and inducement of DNA damage were evaluated by employing the prepared working electrode in pH 5.0, 0.10 M acetate buffer solution with differential pulse voltammetry (DPV). The influences of temperature and metal ions (cupric ions) on the extent of DNA damage were examined. Chlorogenic acid possessed autooxidative activity and could induce DNA damage under certain conditions. The increasing temperature and existing cupric ions could enhance the autooxidative capability of chlorogenic acid and enlarge the extent of DNA damage. It was possible that the DNA damage induced by chlorogenic acid preferentially took place at guanosine‐containing segments, with the formation of 8‐oxo‐deoxyguanosine (a biomarker of DNA oxidative damage). A mechanism on the autooxidative activity of chlorogenic acid and inducing DNA damage was proposed.
Quantitative brain proton MR spectroscopy based on measurement of the relaxation time T1 of water
Authors: Bajzik Gábor , Auer Tibor , Bogner Péter , Aradi Miklós , Kotek Gyula , Repa Imre , Doczi Tamas , Schwarcz Attila 
Published: June 2008

AbstractPurposeTo provide a straightforward method for metabolite quantitation in the brain. Tissue water concentration can be determined in a voxel by measuring T1 and it may provide an internal reference for the calculation of the metabolite concentrations.Materials and MethodsWater‐suppressed stimulated echo acquisition mode spectra were obtained at 1.5T, and the tissue water content was calculated from T1.ResultsThe calculated water content values demonstrated very good agreement with literature data. Metabolite concentrations (mmol/liter) in the gray and white matter: N‐acetyl‐aspartate = 14.02 ± 1.93, creatine = 9.98 ± 1.03, and choline = 1.14 ± 0.24; N‐acetyl‐aspartate = 11.08 ± 2.24, creatine = 7.83 ± 0.66, and choline = 2.05 ± 0.38, respectively.ConclusionThe water content calculated from T1 can yield an internal reference in MR spectroscopy, and the accurate measurement of metabolite concentrations is feasible. The proposed method is simple and can readily be applied in any MR center without the need for complicated corrections or calibration procedures. J. Magn. Reson. Imaging 2008;28:34–38. © 2008 Wiley‐Liss, Inc.
Chronic hepatitis: Role of diffusion‐weighted imaging and diffusion tensor imaging for the diagnosis of liver fibrosis and inflammation
Authors: Taouli Bachir , Chouli Malik , Martin Alastair J. , Qayyum Aliya , Coakley Fergus V. , Vilgrain Valérie 
Published: June 2008

AbstractPurposeTo determine the diagnostic performance of liver apparent diffusion coefficient (ADC) measured with conventional diffusion‐weighted imaging (CDI) and diffusion tensor imaging (DTI) for the diagnosis of liver fibrosis and inflammation.Materials and MethodsBreathhold single‐shot echo‐planar imaging CDI and DTI with b‐values of 0 and 500 second/mm2 was performed in 31 patients with chronic liver disease and 13 normal volunteers. Liver biopsy was performed in all patients with liver disease with a median delay of two days from MRI. Fibrosis and inflammation were scored on a 5‐point scale (0–4). Liver ADCs obtained with CDI and DTI were compared between patients stratified by fibrosis stage and inflammation grade. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the utility of the ADC measures for prediction of fibrosis and inflammation.ResultsPatients with liver fibrosis and inflammation had significantly lower liver ADC than subjects without fibrosis or inflammation with CDI and DTI. For prediction of fibrosis stage ≥ 1 and stage ≥ 2, area under the ROC curve (AUC) of 0.848 and 0.783, sensitivity of 88.5% to 73.7%, and specificity of 73.3% to 72.7% were obtained, for ADC ≤1.40 × 10–3 mm2/second and ≤1.30 × 10–3 mm2/second (using CDI), respectively. For prediction of inflammation grade ≥ 1, AUC of 0.825, sensitivity of 75.0%, and specificity of 78.6% were obtained using ADC ≤ 1.30 × 10–3 mm2/second (using CDI). CDI performed better than DTI for diagnosis of fibrosis and inflammation.ConclusionLiver ADC can be used to predict liver fibrosis and inflammation with acceptable sensitivity and specificity. J. Magn. Reson. Imaging 2008;28:89–95. © 2008 Wiley‐Liss, Inc.
Automatic computation of left ventricular ejection fraction from spatiotemporal information in cine‐SSFP cardiac MR images
Authors: Pednekar Amol S. , Muthupillai Raja , Cheong Benjamin , Flamm Scott D. 
Published: June 2008

AbstractPurposeTo clinically validate an algorithm that automatically computes left ventricular (LV) ejection fraction (LVEF) using a priori geometric and intrinsic spatiotemporal information from cine steady‐state free precession (SSFP) MR images.Materials and MethodsThe algorithm was evaluated in 64 subjects (21 healthy volunteers and 43 patients, LVEF 19–71%). Bland‐Altman analyses were performed on short‐axis slices subdivided into three sections (basal, midcavity, and apical) to assess the impact of morphologic variations on LVEF computation.ResultsThe automated algorithm delineated the clinically applicable endocardial boundary in 1011 of 1078 short‐axis slices (94%). The bias (mean difference) values computed with clinically unusable contours replaced with hand‐drawn equivalents were small for the LV end‐diastolic volume (LVEDV, <11 mL/7%), end‐systolic volume (LVESV, <7 mL/11%), and LVEF (<1.2%). Moreover, these values were within the limits of interobserver and intraobserver variability of experienced observers (LVEDV, <13 mL/8%; LVESV, <12 mL/17%; and LVEF, <5%). In the end‐diastolic phase, the limits of agreement (bias ± 1.96 SD of difference) were small (<5% LVEDV) in all sections. However, in the end‐systolic phase, the limits of agreement were larger for the midcavity (<21% LVESV) and apical (<11% LVESV) slices.ConclusionThis data‐driven algorithm can estimate LVEDV, LVESV, and LVEF with a bias that is comparable to the interobserver and intraobserver variability of experienced observers. J. Magn. Reson. Imaging 2008;28:39–50. © 2008 Wiley‐Liss, Inc.
Apparent wall thickening of cystic renal lesions on MRI
Authors: Gulani Vikas , Adusumilli Saroja , Hussain Hero K. , Vazquez Alberto L. , Francis Isaac R. , Noll Douglas C. 
Published: June 2008

AbstractPurposeTo show that cystic renal lesions that would otherwise meet criteria for simple cysts can demonstrate perceptible walls or increased wall thickness on MRI, sometimes causing these lesions to be “upgraded.” It was hypothesized that thickening of cyst walls on MRI can be artifactual, due to data truncation, applied filtering, and low signal‐to‐noise ratio (SNR).Materials and Methodsk‐Space data for a 4‐cm cyst were created in a 40‐cm field of view (FOV) (512 × 512 matrix). Additional data sets were created using the central 512 × 256 and 512 × 128 points. Noise was simulated so that the cyst SNR was approximately 7, 14, and 20, respectively. Actual wall thickness was set at 0.25 mm, and cyst:wall signal at 1:4. An inverse two‐dimensional (2D) fast Fourier transform (FFT) yielded simulated images. A Fermi filter was applied to reduce ringing. Images/projections were examined for wall thickening. Seven patients with initially thick‐walled cysts on fat‐saturated spoiled gradient‐echo (FS‐SPGR) images were scanned with increasing resolution (256 × 128 and 256 × 256; four patients were also scanned with 512 × 512). Average wall thickness at each resolution was compared using a two‐tailed paired Student's t‐test.ResultsSimulations showed apparent wall thickening at low resolution, improving with higher resolutions. Low SNR and application of the Fermi filter made it difficult to identify ringing as the cause of this thickening. The simulation results were confirmed on seven patients, whose cyst walls proved to be artifactually thickened (P < 0.01).ConclusionThickening of cyst walls on MRI can be artifactual. Upon encountering thick‐walled cystic renal lesions, high‐resolution images can be acquired to exclude apparent thickening. J. Magn. Reson. Imaging 2008;28103–110. © 2008 Wiley‐Liss, Inc.
Depth‐dependent profiles of glycosaminoglycans in articular cartilage by μMRI and histochemistry
Authors: Xia Yang , Zheng ShaoKuan , Bidthanapally Aruna 
Published: June 2008

AbstractPurposeTo quantify the distribution profile of glycosaminoglycans (GAGs) in articular cartilage with the magnetic resonance imaging (MRI) gadolinium (Gd) contrast method (the dGEMRIC procedure in clinical MRI) and correlate with histochemical results.Materials and MethodsFresh canine cartilage from seven humeral heads was harvested. Sixteen cartilage specimens were imaged at 13 μm pixel resolution using the μMRI T1‐Gd method to generate 2D GAG maps in cartilage. Nineteen cartilage specimens from adjacent locations on the same joints were papain‐digested to quantify the bulk GAG content in tissue. In addition, six cartilage specimens were microtomed into 40‐μm serial sections that were parallel with the articular surface. These sections were biochemically analyzed individually to determine the depth‐dependent profiles of GAG concentration.ResultsThe GAG concentrations between the μMRI measurement and the bulk biochemical method have statistically significant agreement. The depth‐dependent GAG profiles from the histochemical method (40 μm depth resolution) have similar line shapes as that determined by μMRI at 13 μm resolution.ConclusionThe GAG concentration as measured by μMRI T1‐Gd contrast method provides an accurate account of the macromolecular content in articular cartilage. J. Magn. Reson. Imaging 2008;28:151–157. © 2008 Wiley‐Liss, Inc.
Pelvic imaging using a t1w fat‐suppressed three‐dimensional dual echo dixon technique at 3T
Authors: Cornfeld Daniel M. , Israel Gary , McCarthy Shirley M. , Weinreb Jeffery C. 
Published: June 2008

AbstractPurposeTo compare two T1‐weighted (T1W) fat‐suppressed sequences for 3D breath‐hold pre‐ and postcontrast fat‐suppressed T1W imaging of the female pelvis at 3T.Materials and MethodsPelvic MRI scans of 16 female patients were retrospectively identified who were scanned with two 3D breath‐hold sequences: 1) a fast spoiled gradient echo sequence with spectral inversion at lipids (SPECIAL) (called 3D FSPGR), and 2) a dual‐echo two‐point Dixon (DE Dixon) sequence. Contrast between soft tissue and fat, soft tissue and fluid, and fat and fluid was measured on pre‐ and postcontrast images. Additionally, two readers subjectively scored the images for degree and homogeneity of fat suppression plus presence and severity of artifacts.ResultsContrast between muscle and myometrium to fat was improved with the Dixon technique (0.61 vs. 0.09 and 0.7 vs. 0.3, respectively, P < 0.001). Both readers agreed that fat suppression was stronger with the Dixon sequence (P < 0.001 and P = 0.06). Artifacts were equivalent (P = 0.53 and 0.65).ConclusionThe 3D DE Dixon sequence achieved stronger fat suppression in the female pelvis when compared to a 3D FSPGR sequence with SPECIAL. J. Magn. Reson. Imaging 2008;28:121–127. © 2008 Wiley‐Liss, Inc.
Cardiac cine MRI: Quantification of the relationship between fast gradient echo and steady‐state free precession for determination of myocardial mass and volumes
Authors: Malayeri Ashkan Akhavan , Johnson W. Craig , Macedo Robson , Bathon Joan , Lima João A.C. , Bluemke David A. 
Published: June 2008

AbstractPurposeTo determine the correlation function between the steady‐state free precession (SSFP) and fast gradient echo (FGRE) cine MRI pulse sequences for measuring the myocardial mass and volumes.Materials and MethodsCardiac cine MRI examinations were acquired in 50 individuals (female: 35, male: 15, mean age 64.1 ± 9.1 years, range 48–83) using SSFP and FGRE cardiac pulse sequences.ResultsThe mean (standard deviation [SD]) left ventricular end diastolic volume measured by SSFP was significantly larger (4.5%) than by FGRE (P < 0.001); this was also the case for end systolic volume (15.0%, P < 0.001). The relationship between SSFP and FGRE measures were linear and highly correlated (P < 0.001) for both left ventricular end diastolic and end systolic volumes (r2 = 0.90 vs. 0.91, respectively). We determined linear regression models to estimate the SSFP values based on the FGRE measures. Slope (intercept) for ejection fraction, stroke volume, and cardiac output were 0.99 (−2.79), 0.77 (17.5), and 0.76 (1.29), respectively.ConclusionLinear relationships exist for key LV function parameters when comparing SSFP and FGRE cine MRI. These results indicate that existing databases and normal values for FGRE LV function may be converted to corresponding LV function values for SSFP MRI. J. Magn. Reson. Imaging 2008;28:60–66. © 2008 Wiley‐Liss, Inc.