bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silicon alleviates the toxicity of cadmium and zinc for maize (Zea mays L.) grown on a contaminated soil
Authors: Patrícia Vieira da Cunha Karina , Williams Araújo do Nascimento Clístenes , José da Silva Airon 
Published: October 2008

AbstractAlthough silicon (Si) is not an essential element, it presents a close relationship with the alleviation of heavy‐metal toxicity to plants. This work was carried out to evaluate the effects of Si application to soil on the amelioration of metal stress to maize grown on a contaminated soil amended with Si (0, 50, 100, 150, and 200 mg kg–1) as calcium silicate (CaSiO3). Additionally, the cadmium (Cd) and zinc (Zn) bioavailability as well as their distribution into soil fractions was also studied. The results showed that adding Si to a Cd‐ and Zn‐contaminated soil effectively diminished the metal stress and resulted in biomass increase in comparison to metal‐contaminated soil not treated with Si. This relied on Cd and Zn immobilization in soil rather than on the increase of soil pH driven by calcium silicate application. Silicon altered the Cd and Zn distribution in soil fractions, decreasing the most bioavailable pools and increasing the allocation of metals into more stable fractions such as organic matter and crystalline iron oxides.
Determination of dithiothreitol in complex protein mixtures by HPLC–MS
Authors: Cindrić Mario , Čepo Tina , Marinc Sabina , Paškvan Ivan , Mijić Ivana , Bindila Laura , Peter‐Katalinić Jasna 
Published: October 2008

AbstractDithiothreitol (DTT) and other reducing agents are typically used in refolding processes of recombinant human proteins during their purification from inclusion bodies. Due to its toxicity, it is essential to monitor the clearance of DTT throughout the analytical flow from the refolding phase to the final formulated product. Here we report a direct, simple, and fast liquid chromatography method using UV and tandem mass spectrometry (MS/MS) detection for DTT evaluation in complex protein mixtures. In aqueous solution DTT exists as an equilibrium mixture of the oxidized and the reduced form (H2DTT → DTTox) and the quantitation tools should therefore be applicable to both forms in a single step or in multiple steps. Oxidation of DTT with aqueous copper(II) nitrate trihydrate solution was introduced to determine a single oxidized compound, i. e. DTTox. Proteins and other components of high molecular masses were separated from DTTox by ultrafiltration. Consequently, efficient separation of the DTTox from other flow‐through mixture components (sugars, polymers, salts, protein stabilizers) was achieved on an Atlantis dC18 column. After chromatographic separation, DTTox was selectively identified by UV absorbance at 285 nm or by selected reaction monitoring, measuring signal transition between m/z 151 → 105. The method was validated in terms of specificity, accuracy, precision, linearity, and limit of quantification and detection. A reversed‐phase HPLC separation method with atmospheric pressure chemical ionization and MS/MS detection in negative ion mode is highlighted as a viable alternative to currently existing quantitation methods involving DTT derivatization and HPLC fluorescence detection. The described approach offers simple, straightforward, selective, and high‐throughput DTT quantitation in protein mixtures.
Headspace single drop and hollow fiber liquid phase microextractions for HPLC determination of phenols
Authors: Wu Yunli , Hu Bin , Hou Yanli 
Published: October 2008

AbstractTwo methods based on headspace single drop microextraction (HS‐SDME) and headspace hollow fiber liquid phase microextraction (HS‐HF‐LPME) were developed and critically compared with HPLC‐UV determination of phenols (including phenol (Ph), 2‐chlorophenol (CP), 2,4‐dichlorophenol (DCP) and 2,4,6‐trichlorophenol (TCP)) in this paper. The significant parameters affecting the extraction efficiency of the target analytes in both extraction modes were studied and the optimal extraction conditions were established. Under the optimal conditions, the detection limits (S/N = 3) for Ph, CP, DCP and TCP obtained by HS‐SDME‐HPLC‐UV and HS‐HF‐LPME‐HPLC‐UV were 2.1, 0.2, 0.8,1.1 ng/mL and 4.2, 0.4, 0.4, 0.4 ng/mL with enrichment factors of 15.8, 198.9, 159.7, 194.8 and 9.2, 149.9, 301.9, 411.1, respectively. The RSDs obtained by HS‐SDME‐HPLC‐UV and HS‐HF‐LPME‐HPLC‐UV were 3.7, 4.0, 9.8, 6.7% and 6.3, 3.6, 3.1, 4.8% for Ph, CP, DCP and TCP, respectively. Both extraction modes have a comparable analytical performance, but HS‐HF‐LPME was more robust than HS‐SDME, while HS‐SDME was simpler than HS‐HF‐LPME. The two headspace microextraction modes were applied for HPLC‐UV determination of target phenols in water, honey and toner samples, and the determined values obtained by both techniques were in good agreement with each other.
Main traumatic events in Europe: PTSD in the European study of the epidemiology of mental disorders survey
Authors: Darves‐Bornoz Jean‐Michel , Alonso Jordi , de Girolamo Giovanni , Graaf Ron de , Haro Josep‐Maria , Kovess‐Masfety Viviane , Lepine Jean‐Pierre , Nachbaur Gaëlle , Negre‐Pages Laurence , Vilagut Gemma , Gasquet Isabelle 
Published: October 2008

AbstractA potentially traumatic event (PTE) contributes to trauma through its frequency, conditional probability of posttraumatic stress disorder (PTSD), and experience of other PTEs. A cross‐sectional survey was conducted, enrolling 21,425 adults nationally representative of six European countries. Using the WHO‐Composite International Diagnostic Interview, 8,797 were interviewed on 28 PTEs and PTSD. Prevalence of 12‐month PTSD was 1.1%. When PTSD was present, the mean number of PTEs experienced was 3.2. In a multivariate analysis on PTEs and gender, six PTEs were found to be more traumatic, and to explain a large percentage of PTSD, as estimated by their attributable risk of PTSD: rape, undisclosed private event, having a child with serious illness, beaten by partner, stalked, beaten by caregiver.
Poisson regression for modeling count and frequency outcomes in trauma research
Authors: Gagnon David R. , Doron‐LaMarca Susan , Bell Margret , O'Farrell Timothy J. , Taft Casey T. 
Published: October 2008

AbstractThe authors describe how the Poisson regression method for analyzing count or frequency outcome variables can be applied in trauma studies. The outcome of interest in trauma research may represent a count of the number of incidents of behavior occurring in a given time interval, such as acts of physical aggression or substance abuse. Traditional linear regression approaches assume a normally distributed outcome variable with equal variances over the range of predictor variables, and may not be optimal for modeling count outcomes. An application of Poisson regression is presented using data from a study of intimate partner aggression among male patients in an alcohol treatment program and their female partners. Results of Poisson regression and linear regression models are compared.
Different types of exposure to the 2004 tsunami are associated with different levels of psychological distress and posttraumatic stress
Authors: Wahlström Lars , Michélsen Hans , Schulman Abbe , Backheden Magnus 
Published: October 2008

AbstractThe impact of traumatic exposure on psychological distress and posttraumatic stress was investigated at 14 months through self‐report in 1,505 Swedish tourists who survived the 2004 Indian Ocean Tsunami. Exposure, differentiated in single and multiple types, was associated with different levels of impaired mental health measured by General Health Questionnaire (GHQ) and Impact of Event Scale‐Revised (IES‐R). Additionally, having sole exposure to subjective life threat brought about specific psychological effects. Some demographic factors are associated with outcome on either the GHQ or the IES‐R. Identifying specific types of exposure of disaster survivors may be a way to identify individuals who could be screened for psychological ill health at a later point in time.
Creation of a community violence exposure scale: Accounting for what, who, where, and how often
Authors: Suglia Shakira Franco , Ryan Louise , Wright Rosalind J. 
Published: October 2008

AbstractPrevious research has used the Rasch model, a method for obtaining a continuous scale from dichotomous survey items measuring a single latent construct, to create a scale of community violence exposure. The authors build upon previous work and describe the application of a Rasch model using the continuation ratio model to create an exposure to community violence (ETV) scale including event circumstance information previously shown to modify the impact of experienced events. They compare the Rasch ETV scale to a simpler sum ETV score, and estimate the effect of ETV on child posttraumatic stress symptoms. Incorporating detailed event circumstance information that is grounded in traumatic stress theory may reduce measurement error in the assessment of children's community violence exposure.
Schweißen von Leichtmetallen verlangt modifizierte Prozesse
Authors: Dzelnitzki Dirk 
Published: October 2008

AbstractIm modernen Luft‐ und Raumfahrzeugbau hat sich das Laserstrahl‐Schweißen als alternatives Fügeverfahren etabliert. Neue, leichtere Werkstoffe, die mehr und mehr zum Einsatz kommen, verlangen aber nach Prozessmodifikationen, damit das Schweißergebnis die hohen qualitative Anforderungen voll erfüllt. Beim Laserstrahl‐Schweißen von Aluminiumlegierungen lassen sich präzise und hochwertige Schweißnähte beispielsweise durch den Einsatz eines Drahtvorschub‐Systems erreichen. Um hierbei einen reibungslosen Prozessablauf zu gewährleisten, bedarf es neben der präzisen Zufuhr des Drahts auch des genauen Zusammenspiels aller Systemkomponenten.
Sub‐millimeter resolution 3D optical imaging of living tissue using laminar optical tomography
Authors: Hillman E.M.C. , Burgess S.A. 
Published: October 2008

AbstractIn‐vivo imaging of optical contrast in living tissues can allow measurement of functional parameters such as blood oxygenation and detection of targeted and active fluorescent contrast agents. However, optical imaging must overcome the effects of light scattering, which limit the penetration depth and can affect quantitation and sensitivity. This article focuses on a technique for high‐resolution, high‐speed depth‐resolved optical imaging of superficial living tissues called laminar optical tomography (LOT), which is capable of imaging absorbing and fluorescent contrast in living tissues to depths of 2–3 mm with 100–200 micron resolution. An overview of the advantages and challenges of in‐vivo optical imaging is followed by a review of currently available techniques for high‐resolution optical imaging of tissues. LOT is then described, including a description of the imaging system design and discussion of data analysis and image reconstruction approaches. Examples of recent applications of LOT are then provided and compared to other existing technologies.
Modification of single molecule fluorescence near metallic nanostructures
Authors: Lakowicz J.R. , Fu Yi 
Published: October 2008

AbstractIn recent years there has been a growing interest in the interactions of fluorophores with metallic nanostructures or nanoparticles. The spectra properties of fluorophores can be dramatically modified by near‐field interactions with the electron clouds present in metals. Near‐field interactions are those occurring within a wavelength distance of an excited fluorophore. These interactions modify the emission in ways not seen in ensemble fluorescence experiments. In this review we provide an insightful description of the photophysics of metal plasmons and near‐field interactions. Additionally, we summarize recent works on single‐molecule studies on metal‐fluorophore interactions and suggest how these effects will result in new classes of experimental procedures, novel probes, bioassays and devices.
Institutional constraints on organizations: the case of Spanish car dealerships
Authors: Arruñada Benito , Vázquez Luis , Zanarone Giorgio 
Published: October 2008

AbstractWe study the effect of organizational choice and institutions on the performance of Spanish car dealerships. Using outlet‐level data from 1994, we find that vertically integrated dealerships showed substantially lower labor productivity, higher labor costs and lower profitability than franchised ones. Despite these gaps in performance, no vertically integrated outlet was separated until 1994, yet the few outlets that were eventually separated systematically improved their performance. We argue that the conversion of integrated outlets into franchised ones involved significant transaction costs, due to an institutional environment favoring permanent, highly unionized employment relations. In line with this argument, we find that the observed separations occurred in distribution networks that underwent marked reductions in worker unionization rates, following the legalization of temporary labor contracts. Copyright © 2008 John Wiley & Sons, Ltd.
Corporate governance and firm efficiency: evidence from China's publicly listed firms
Authors: Lin Chen , Ma Yue , Su Dongwei 
Published: October 2008

AbstractThis paper applies a two‐stage, double bootstrapping data envelope analysis approach to investigate whether and to what extent various distinctive corporate governance practices affect productive efficiency in a sample of 461 publicly listed manufacturing firms in China between 1999 and 2002. We find that firm efficiency is negatively related to state ownership while positively related to public and employee share ownership. In addition, the relationship between ownership concentration and firm efficiency is U‐shaped, indicating the presence of tunneling activities by the largest shareholder. Among three types of controlling shareholder, state exerts the most negative impact on firm efficiency, followed by state‐owned legal entities. These results provide strong evidence that political interferences have reduced firm efficiency. It shows that the proportion of outside directors and the number of board meetings are positively associated with firm efficiency, suggesting that board of directors can be an effective internal governance mechanism. Furthermore, provincial market development, a proxy for the strength of external governance mechanism, is positively related to firm efficiency. Overall, our findings illustrate that restructuring state‐owned enterprises via improvements in corporate governance has enhanced firm efficiency, but partial privatization without transfer of ownership and control from the state to the public remains a major source of inefficiency in corporate China. Copyright © 2008 John Wiley & Sons, Ltd.
Applause sign in parkinsonian disorders and Huntington's disease
Authors: Wu Laura J.C. , Sitburana Oraporn , Davidson Anthony , Jankovic Joseph 
Published: October 2008

AbstractThe applause sign has been previously reported to be indicative of neurodegenerative disorders, such as progressive supranuclear palsy (PSP). In order to determine the sensitivity, specificity, and positive predictive value, we tested it in patients with PSP, Parkinson's disease (PD), multiple system atrophy (MSA), corticobasal degeneration (CBD), and Huntington's disease (HD). Subjects were asked to clap three times after demonstration by the examiner. The performance was scored as follows: 3 = claps only three times; 2 = claps four times; 1 = claps 5 to 10 times; 0 = claps >10 times. The clap test was videotaped and rated. Patients with CBD, MSA, and PSP showed significant differences in clap scores compared with normal controls. The test differentiated patients with CBD from those with PD (P < 0.005) and HD (P < 0.005), but failed to discriminate patients with PSP from other parkinsonian groups. The specificity of the applause sign is 100% in distinguishing parkinsonian patients from normal subjects with the highest sensitivity in CBD patients. We concluded that the applause sign is highly specific for parkinsonian disorders but it is not a specific sign for PSP; it appears to be most sensitive for CBD. © 2008 Movement Disorder Society
Excessive postural sway and the risk of falls at different stages of Parkinson's disease
Authors: Frenklach Anna , Louie Stephanie , Koop Mandy Miller , Bronte‐Stewart Helen 
Published: October 2008

AbstractExcessive postural sway may result in falls in Parkinson's disease (PD). We measured postural sway using the sensory organization test (SOT) of dynamic posturography in static (platform still) and dynamic (sway referenced platform) conditions with normal, no and inappropriate visual feedback in 102 subjects with PD, off medication. Twenty‐five healthy subjects were used as age‐matched controls. Eighteen very early stage PD subjects had never used dopaminergic medication. Postural sway was normal in those subjects in all conditions, but was abnormal in subjects with more advanced symptoms (UPDRS III > 20, P < 0.01). Postural sway increased with disease severity in all conditions except static, eyes closed (P < 0.0001). We developed the SOT Fall Severity Scale (SOTFSS) from the number of times postural sway was so large that the subject had to take a step (registered as a “fall”) and showed that falls mainly occurred in dynamic conditions, and were correlated with disease severity (P < 0.0001). In dynamic conditions the SOTFSS was correlated with the retropulsion score from the UPDRS III (N = 102, P < 0.0001) and with the subjects' self‐reported fall frequency from the UPDRS II (N = 62, SOT5: P = 0.0419, SOT6: P = 0.0034). © 2008 Movement Disorder Society
All‐author vs. first‐author co‐citation analysis of the Information Science field using Scopus
Authors: Zhao Dangzhi , Strotmann Andreas 
Published: October 2008

AbstractAlthough many studies on the various ways of allocating credit among co‐authors have brought into general recognition that different citation counting methods can result in quite different author rankings, studies on different author co‐citation counting methods are still largely missing. This paper examines whether different co‐citation counting methods produce different results in author co‐citation analysis studies of the intellectual structure of research fields, and if so, in what ways they differ. Our results indicate that, with respect to the major specialties and how they relate to each other, the intellectual structures of the Information Science field identified through author co‐citation analyses based on different co‐citation counting methods are largely equivalent, but when it comes to detailed structure, results differ in a number of ways. In particular, classic first‐author co‐citation analysis appears to better represent the theoretical and methodological aspects of the field whereas all‐author co‐citation analysis favors more recent empirical studies, and picks out some tightly collaborative research groups or projects. We experiment with using meaningful diagonal values in a co‐citation matrix rather than using statistically generated values, and observe favorable results. We also employ a new visualization technique for reporting the results of a classic author co‐citation analysis, using a bipartite graph that represents all the information in the factor matrix of specialties and author loadings as author and factor vertices connected by edges with loadings as similarity‐measure line values, laid out algorithmically in two dimensions.
Verification of information behavioral grammar: Role of searchers
Authors: Miwa Makiko 
Published: October 2008

AbstractThis paper reports on a verification study of the information behavioral grammar (IBG) model initially developed in 2000. We used a modified critical incident technique to identify how social science faculty members' information‐seeking processes are engaged differently for their differing role tasks. A semistructured interview was conducted on the recently experienced information‐seeking processes of researchers, teachers, and personal/family decision makers. As a result, 31 information‐seeking processes (nine on research, six on teaching, and 16 for personal/family decision making) were identified. Contents of recorded interviews were analyzed for associations among behavioral, cognitive, affective, social and environmental aspects using the constant‐comparative method. The characteristics of information‐seeking processes for each role were identified and compared with the IBG model. Results indicate that the IBG model fits the patterns identified for social scientists' information‐seeking processes for research and teaching. However, we could not obtain reliable data to verify the applicability of the IBG model to their information‐seeking processes for personal/family decision making, mainly because these processes were deeply embedded in their everyday life activities and, in most cases, were taken for granted, which made difficult recall of the exact sequence of actions with associated cognitive, affective, social and environmental situations.
An MR guidewire based on micropultruded fiber‐reinforced material
Authors: Krueger Sascha , Schmitz Sebastian , Weiss Steffen , Wirtz Daniel , Linssen Marita , Schade Heinz , Kraemer Nils , Spuentrup Elmar , Krombach Gabriele , Buecker Arno 
Published: October 2008

AbstractA novel fiber‐reinforced material for the realization of MR guidewires, made using a newly‐developed production process, is presented. The MR‐safe artificial material provides a high stiffness and torque and allows the production, in a large range of sizes, of nonmetallic MR guidewires with similar mechanical properties as conventional metallic guidewires. Based on this material, a passively visualized MR guidewire has been developed, and was found to conform to existing standards on mechanical stability. Handling and steerability were evaluated in animal studies and were found to be comparable with conventional metallic guidewires. X‐ray visibility is provided by a BaSO4‐ and tungsten‐doped jacket. A hydrophilic coating improves sliding properties and hemocompatibility. Magn Reson Med 60:1190–1196, 2008. © 2008 Wiley‐Liss, Inc.
Gadolinium‐modulated 19F signals from perfluorocarbon nanoparticles as a new strategy for molecular imaging
Authors: Neubauer Anne M. , Myerson Jacob , Caruthers Shelton D. , Hockett Franklin D. , Winter Patrick M. , Chen Junjie , Gaffney Patrick J. , Robertson J. David , Lanza Gregory M. , Wickline Samuel A. 
Published: October 2008

AbstractRecent advances in the design of fluorinated nanoparticles for molecular magnetic resonance imaging (MRI) have enabled specific detection of 19F nuclei, providing unique and quantifiable spectral signatures. However, a pressing need for signal enhancement exists because the total 19F in imaging voxels is often limited. By directly incorporating a relaxation agent, gadolinium (Gd), into the lipid monolayer that surrounds the perfluorocarbon (PFC), a marked augmentation of the 19F signal from 200‐nm nanoparticles was achieved. This design increases the magnetic relaxation rate of the 19F nuclei fourfold at 1.5 T and effects a 125% increase in signal—an effect that is maintained when they are targeted to human plasma clots. By varying the surface concentration of Gd, the relaxation effect can be quantitatively modulated to tailor particle properties. This novel strategy dramatically improves the sensitivity and range of 19F MRI/MRS and forms the basis for designing contrast agents capable of sensing their surface chemistry. Magn Reson Med 60:1066–1072, 2008. © 2008 Wiley‐Liss, Inc.