bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impedance spectra and computation of chemical diffusion coefficients in CuIn3Te5 single crystals with a massive Cu motion
Authors: Diaz R , Cervera M , Rueda F 
Published: May 2012

Abstract
Two single crystals of the same ingot and a polycrystal with compositions close to CuIn2Te3.5, CuIn3Te5 and CuIn4Te6, respectively, have been studied using impedance spectroscopy at different temperatures in the 20–120 °C range. The negative imaginary impedance part, −Z
**, as a function of the real impedance part, Z
*, (Nyquist plots) can be fitted to one or two semicircles associated with the Warburg diffusion and related one or two mobile ions, depending on the slice composition. In dc current and using the current intensity decay method at 20 °C, the conductivity as a function of time permits one to compute the diffusion coefficients of one or two mobile ions observed in impedance spectroscopy. The diffusion coefficients of the Cu ion are higher than those in CuInSe2 and are associated with the number of copper vacancies, VCu, and indium–copper antisites, InCu, in the Cu sublattice. EDAX measurements in the slice profile, before and after the electrical analysis, confirm a massive motion of Cu atoms along the slice thickness. In all samples, there is a region with composition close to CuIn1.7Te3 and a new atomic distribution, different in each sample depending on the initial composition and their structure. The ionic motion permits one to understand the behaviour of chalcopyrite thin films when they are grown with a composition gradient (from a Cu-rich chalcopyrite to an In-rich one).
Combination effects of tilted electric and magnetic fields on donor binding energy in a GaAs/AlGaAs cylindrical quantum dot
Authors: Zeng Zaiping , Garoufalis Christos S , Baskoutas Sotirios 
Published: May 2012

Abstract
We have performed a systematic study on the ground-state binding energy of an on-center donor impurity confined in a GaAs/Al0.3Ga0.7As cylindrical quantum dot (QD), subjected to simultaneously applied electric and magnetic fields. The two fields are tilted with respect to the QD growth direction and they are either parallel or perpendicular to each other. All the calculations are based on the potential morphing method which is employed within the framework of the effective-mass approximation. Our results show that when the tilted electric and magnetic fields are parallel, the magnetic shift of the donor binding energy is a monotonic function of the magnetic field strength. On the other hand, when the two fields are perpendicular to each other, the magnetic shift of the donor binding energy varies nonmonotonically with respect to the magnetic field strength, exhibiting a minimum value at a critical magnetic field strength. The position of this minimum value and its dependence on the QD size, its aspect ratio and the orientation of the tilted magnetic field is systematically investigated. Moreover, we discuss in detail the competition effects which appear in the presence of the two fields, showing that the critical line which corresponds to zero shift of the donor binding energy can be manipulated by suitably adjusting the QD size, the aspect ratio and the relative orientation of the two fields.
Enhancing the performance of nanostructured zinc oxide/polymer-based hybrid solar cells using ammonia as a structural and interfacial modifier
Authors: Pradhan S , Karak S , Dhar A 
Published: May 2012

Abstract
We have investigated the effect of ammonia solution treatment on the ZnO nanostructure and its influence on the photovoltaic device performance of conjugated polymer/nanostructured ZnO-based hybrid solar cells (HSC). The ammonia solution was used as the etching agent on the ZnO nanostructure as well as the interface modifier between ZnO/polymer interfaces which led to a better open circuit voltage (V
OC). The etching of ZnO nanostructure provides better polymer infiltration inside the nanostructure arrays with higher effective donor–acceptor interface area. We have also investigated the absorption and photoluminescence behaviour of the NH3-treated device in comparison with an untreated device. The study showed that the NH3 etching with optimized time over ZnO nanostructure enhances the absorption, charge carrier separation, recombination suppression which leads to the improvement in the overall performance of the photovoltaic device.
Limitations of x-ray reflectometry in the presence of surface contamination
Authors: Gil D L , Windover D 
Published: May 2012

Abstract
Intentionally deposited thin films exposed to atmosphere often develop unintentionally deposited few-monolayer films of surface contamination. This contamination arises from the diverse population of volatile organics and inorganics in the atmosphere. Such surface contamination can affect the uncertainties in determination of thickness, roughness and density of thin-film structures by x-ray reflectometry (XRR). Here we study the effect of a 0.5 nm carbon surface contamination layer on thickness determination for a 20 nm titanium nitride thin film on silicon. Uncertainties calculated using Markov-chain Monte Carlo Bayesian statistical methods from simulated data of clean and contaminated TiN thin films are compared at varying degrees of data quality to study (1) whether synchrotron sources cope better with contamination than laboratory sources and (2) whether cleaning off the surface of thin films prior to XRR measurement is necessary. We show that, surprisingly, contributions to uncertainty from surface contamination can dominate uncertainty estimates, leading to minimal advantages in using synchrotron-over laboratory-intensity data. Further, even prior knowledge of the exact nature of the surface contamination does not significantly reduce the contamination's contribution to the uncertainty in the TiN layer thickness. We conclude, then, that effective and standardized cleaning protocols are necessary to achieve high levels of accuracy in XRR measurement.
A double‐blind, randomized, parallel, placebo‐controlled study examining the effect of cross‐linked polyelectrolyte in heart failure patients with chronic kidney disease
Authors: Costanzo Maria Rosa , Heywood J. Thomas , Massie Barry M. , Iwashita Julie , Henderson Lee , Mamatsashvili Merab , Sisakian Hamayak , Hayrapetyan Hamlet , Sager Philip , van Veldhuisen Dirk J. , Albrecht Detlef 
Published: May 2012

AimsThis double‐blind, randomized, parallel, placebo‐controlled investigation evaluated the effects of cross‐linked polyelectrolyte (CLP) on serum potassium and measures of congestion in patients with heart failure (HF) and chronic kidney disease (CKD).Methods and resultsThe primary endpoint was change in serum potassium over time. Exploratory endpoints included: weight, physician and patient assessment of exertional dyspnoea, effect on N‐terminal pro brain natriuretic peptide (NT‐proBNP) levels, New York Heart Association (NYHA) classification, 6 min walk test (6MWT), and quality of life by Kansas City Cardiomyopathy Questionnaire (KCCQ). Serum potassium was similar in CLP (n =59) and placebo (n =52) groups throughout the 8‐week study. Weight loss was greater in the CLP than in the placebo group at Weeks 1 (P =0.014) and 2 (P =0.004), and this trend continued until the end of the study. After 8 weeks, by physician assessment, the percentage of patients experiencing marked or disabling dyspnoea tended to be lower in the CLP than in the placebo group (7.3% vs. 23.9%, P =0.128). Fewer patients in the CLP than in the placebo group had NT‐proBNP levels >1000 pg/mL at Week 4 (P =0.039) and Week 8 (P =0.065). The proportion of patients improving by at least one NYHA functional class over the study was higher in the CLP than in the placebo group (48.8% vs. 17.4%; P =0.002). Effects on 6MWT at Week 8 (p =0.072) and quality of life (overall KCCQ score) at Week 4 (p =0.005) and 8 (P =0.062) all favoured the CLP cohort. Four treatment‐unrelated deaths occurred in the CLP group and none in the placebo group (P =0.056).ConclusionIn advanced, symptomatic HF with CKD, CLP is associated with beneficial clinical effects without significant serum potassium changes.Trial registration: NCT01265524.
Why promote sold‐out concerts? A Durkheimian analysis
Authors: Duffett Mark 
Published: May 2012

PurposeThe aim of this research paper is to examine why concert promoters sometimes advertise sold‐out live music shows when nobody can buy tickets any longer.Design/methodology/approachDurkheim's theory of religion as a thrilling social activity is used to hypothesize that the advertising of sold‐out events reminds audiences that star performers are popular and therefore helps to generate the “buzz” around them. Interviews with a series of promoters from the USA, UK and Canada revealed, however, that they see more immediate and mundane reasons for advertising sold‐out shows, including building the artist's career profile and training consumers to buy next time round.FindingsIt was found that promoters could also organize the sales and advertising process to bring sold‐out events into being. While their explanations diverged from a Durkheimian schema, the results of their actions did not. In effect they serendipitously did cultural work to further the Durkheimian process without being consciously concerned by it as an explanation of motives.Originality/valueThis paper suggests that the Durkheimian model illuminates a point of connection between commerce and affect in the reception of star performances. Further research on live music using the model as a hypothesis may therefore be useful.
Meta‐analysis: IL‐28B genotype and sustained viral clearance in HCV genotype 1 patients
Authors: Rangnekar A. S. , Fontana R. J. 
Published: May 2012

SummaryBackgroundPolymorphisms in the IL‐28B region are a strong predictor of sustained virologic response (SVR) in individual studies of HCV genotype 1 patients receiving peginterferon (pegIFN) and ribavirin.AimTo obtain a pooled odds ratio (OR) of SVR in patients of varying race with the favourable IL‐28B genotype compared to those with the unfavourable genotype.MethodsA literature search was conducted using online databases and a review of conference abstracts. A random effects meta‐analysis was performed and study heterogeneity and publication bias were assessed.ResultsThere were 21 individual studies of HCV genotype 1 patients of varying ethnicity treated with pegIFN and ribavirin. The pooled prevalence of the favourable IL‐28B genotype varied by race (73% vs. 41% vs. 13% in 2612 Asians, 3110 Caucasians and 452 African‐Americans, respectively, P < 0.001). However, the strength of association of the IL‐28B genotype with SVR was similar in all three racial groups (Caucasians: odds ratio (OR) 3.88, 2.75–5.49, African‐Americans: OR 4.63, 2.52–8.50 and Asians OR 5.66, 3.99–8.02, all P < 0.001). The IL‐28B genotype was also associated with SVR in 263 HIV/HCV co‐infected Caucasians (OR 5.49, 3.02–9.96, P < 0.001). Study quality score and anti‐viral treatment regimen did not impact the strength of the association in patient subgroups nor in the pooled population.Conclusions
IL‐28B genotype is significantly associated with SVR in HCV genotype 1 patients of varying race, as well as in HIV co‐infected patients, receiving pegIFN and ribavirin. IL‐28B testing in conjunction with other pre‐treatment parameters may prove useful in counselling HCV patients.
Climate change and voltinism in Californian insect pest species: sensitivity to location, scenario and climate model choice
Authors: Ziter Carly , Robinson Emily A. , Newman Jonathan A. 
Published: May 2012

AbstractExperimental studies of the impact of climatic change are hampered by their inability to consider multiple climate change scenarios and indeed often consider no more than simple climate sensitivity such as a uniform increase in temperature. Modelling efforts offer the ability to consider a much wider range of realistic climate projections and are therefore useful, in particular, for estimating the sensitivity of impact predictions to differences in geographical location, and choice of climate change scenario and climate model projections. In this study, we used well‐established degree‐day models to predict the voltinism of 13 agronomically important pests in California, USA. We ran these models using the projections from three Atmosphere–Ocean Coupled Global Circulation Models (AOCGCMs or GCMs), in conjunction with the SRES scenarios. We ran these for two locations representing northern and southern California. We did this for both the 2050s and 2090s. We used anova to partition the variation in the resulting voltinism among time period, climate change scenario, GCM and geographical location. For these 13 pest species, the choice of climate model explained an average of 42% of the total variation in voltinism, far more than did geographical location (33%), time period (17%) or scenario (1%). The remaining 7% of the variation was explained by various interactions, of which the location by GCM interaction was the strongest (5%). Regardless of these sources of uncertainty, a robust conclusion from our work is that all 13 pest species are likely to experience increases in the number of generations that they complete each year. Such increased voltinism is likely to have significant consequences for crop protection and production.
Unintentional extrusion of mineral trioxide aggregate: a report of three cases
Authors: Nosrat A. , Nekoofar M. H. , Bolhari B. , Dummer P. M. H. 
Published: May 2012

AbstractAimMineral trioxide aggregate (MTA) is the material of choice for apical barrier techniques during root canal treatment of teeth with open apices. However, the precise control of MTA during the placement of an apical plug is challenging. This article describes the outcomes of unintentional extrusion of MTA into the periradicular tissue during apical barrier treatment in three cases.SummaryThree cases of maxillary central incisors in adult patients with open apices were referred for treatment. After conventional access and canal preparation, MTA was placed into the apical portion of the root canals to act as an apical barrier/plug. A large increment of MTA was extruded in all cases. In Case 1, after a 4‐year follow‐up, the extruded MTA had resorbed and the periradicular lesion had healed. In Cases 2 and 3, after follow‐up, the patients remained symptomatic and were scheduled for periradicular surgery. In Case 2, soft unset particles of MTA were present in the lesion and were curetted. In Case 3, the extruded MTA had set hard but was sandwiched between the oral mucosa and bone; its removal relieved the pain experienced on buccal palpation.Key learning points

Extruded MTA may not harden and may be associated with ongoing periapical irritation;
Extruded set MTA when encapsulated in the mucosa and not surrounded by bony matrix may act as a mechanical irritant on palpation;
Mineral trioxide aggregate should be confined to the root canal system;
Teeth where MTA has been extruded beyond the foramen should be followed‐up to monitor the outcome.
Influences of superheated steaming and roasting on the quality and antioxidant activity of cooked sweet potatoes
Authors: Wang Tzu‐Ching , Chen Bang‐Yuan , Shen Ying‐Pei , Wong Jhen‐Jhan , Yang Chi‐Ching , Lin Ta‐Chen 
Published: May 2012

SummaryRoasted sweet potato is a popular food because of the attractive aroma produced by the Maillard reaction. However, the roasting process may lead to charred skin. Cooking with superheated (saturated) steam provides a solution to this problem. As the results show, when comparing sweet potatoes cooked by superheated steam, and those roasted for 40 min, respectively, the degree of gelatinisation could reach as high as 95% with only 140 °C superheated steam, while roasting required temperatures up to 240 °C. Moreover, in appearance, the skins of the sweet potatoes cooked using superheated steam were not charred like the roasted ones. However, sweet potatoes roasted at 240 °C for 60 min had the highest overall sensory score. When comparing the antioxidant activity, the sweet potatoes cooked by superheated steam had the highest content of total phenol and flavonoids, the best scavenging ability of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and the highest ferric‐reducing ability of plasma (FRAP).
Explaining variation in perceived team effectiveness: results from eleven quality improvement collaboratives
Authors: Strating Mathilde MH , Nieboer Anna P 
Published: May 2012

Aims and objectives.  Explore effectiveness of 11 collaboratives focusing on 11 different topics, as perceived by local improvement teams and to explore associations with collaborative‐, organisational‐ and team‐level factors.Background.  Evidence underlying the effectiveness of quality improvement collaboratives is inconclusive and few studies investigated determinants of implementation success. Moreover, most evaluation studies on quality improvement collaboratives are based on one specific topic or quality problem, making it hard to compare across collaboratives addressing different topics.Design.  A multiple‐case cross‐sectional study.Methods.  Quality improvement teams in 11 quality improvement collaboratives focusing on 11 different topics. Team members received a postal questionnaire at the end of each collaborative. Of the 283 improvement teams, 151 project leaders and 362 team members returned the questionnaire.Results.  Analysis of variance revealed that teams varied widely on perceived effectiveness. Especially, members in the Prevention of Malnutrition and Prevention of Medication Errors collaboratives perceived a higher effectiveness than other groups. Multilevel regression analyses showed that educational level of professionals, innovation attributes, organisational support, innovative culture and commitment to change were all significant predictors of perceived effectiveness. In total, 27·9% of the individual‐level variance, 57·6% of the team‐level variance and 80% of the collaborative‐level variance could be explained.Conclusion.  The innovation’s attributes, organisational support, an innovative team culture and professionals’ commitment to change are instrumental to perceived effectiveness. The results support the notion that a layered approach is necessary to achieve improvements in quality of care and provides further insight in the determinants of success of quality improvement collaboratives.Relevance to clinical practice.  Understanding which factors enhance the impact of quality improvement initiatives can help professionals to achieve breakthrough improvement in care delivery to patients on a wide variety of quality problems.
Review: analysis of parasite and other skewed counts
Authors: Alexander Neal 
Published: May 2012

AbstractObjective To review methods for the statistical analysis of parasite and other skewed count data.Methods Statistical methods for skewed count data are described and compared, with reference to a 10‐year period ofTropical Medicine and International Health (TMIH). Two parasitological datasets are used for illustration.Results The review ofTMIHfound 90 articles, of which 89 used descriptive methods and 60 used inferential analysis. A lack of clarity is noted in identifying the measures of location, in particular the Williams and geometric means. The different measures are compared, emphasising the legitimacy of the arithmetic mean for the skewed data. In the published articles, thettest and related methods were often used on untransformed data, which is likely to be invalid. Several approaches to inferential analysis are described, emphasising (1) non‐parametric methods, while noting that they are not simply comparisons of medians, and (2) generalised linear modelling, in particular with the negative binomial distribution. Additional methods, such as the bootstrap, with potential for greater use are described.Conclusions Clarity is recommended when describing transformations and measures of location. It is suggested that non‐parametric methods and generalised linear models are likely to be sufficient for most analyses.
Frequency of antibodies to Toxocara in Cuban schoolchildren
Authors: Sariego I. , Kanobana K. , Junco R. , Vereecken K. , Núñez F. A. , Polman K. , Bonet M. , Rojas L. 
Published: May 2012

AbstractObjective  The aim of the study was to determine the frequency of antibodies to Toxocara in Cuban schoolchildren.Methods  The frequency of antibodies to Toxocara canis was assessed with a commercial enzyme‐linked immunosorbent assays kit in school‐aged children from two municipalities of Cuba. Univariate analysis and a multivariable logistic regression analysis adjusted for age, sex, municipality and co‐infection with helminth and/or protozoa were conducted.Results  The percentage of children with antibodies to Toxocara was 38.8% (392/1011; 95% CI = 36.8–42.8). Antibody positivity was significantly associated with gender and co‐infections with intestinal parasites, but not with age or municipality.Conclusion  Cuban children are highly exposed to the Toxocara parasite, corresponding well with reported environmental contamination with Toxocara parasite eggs and T. canis prevalences in dogs in Cuba. Relevant policy makers and the Cuban population need to be better informed about this preventable infection.
Novel SNP development and analysis at a NADP+‐specific IDH enzyme gene in a four species mixed oak forest
Authors: Vidalis A. , Curtu A. L. , Finkeldey R. 
Published: May 2012

AbstractClosely related Quercus species generally exhibit low levels of genetic differentiation despite their ecological and morphological differences. However, at a few so‐called ‘outlier’ loci they seem to remain genetically distinct. Isocitrate dehydrogenases (IDH) are key enzymes involved in the metabolic pathway of the citrate cycle. IDH has also been characterised as an ‘outlier’ marker, significantly differentiating the closely related Q. robur and Q. petraea with the isozyme technique. This ability to differentiate the species was tested here at molecular level: 13 single nucleotide polymorphism (SNP) markers were identified and developed within a NADP+‐specific IDH gene in Quercus spp. and applied as molecular markers in a four species mixed oak forest in eastern Europe, where Q. robur, Q. petraea, Q. pubescens and Q. frainetto naturally co‐exist. From the 13 developed SNPs, three groups were formed: non‐synonymous, synonymous and non‐coding SNPs. The levels of total gene diversity were moderate for all species investigated. The non‐synonymous SNPs showed lower levels of gene diversity. Overall, the four closely related Quercus spp. were significantly differentiated (except Q. petraea with Q. frainetto). Analysis of non‐random association of alleles revealed no clear physical clustering of the SNP sites in significant linkage disequilibrium (LD). However, separate LD analysis for each species showed a lower number of sites in significant LD for Q. robur than for the other species, possibly reflecting the history of the species in this specific geographical site and less efficient recombination effect due to the larger effective population size of Q. robur. Eleven statistically significant associations were found between seven SNPs and morphological traits that are commonly used to differentiate oak species.