bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gold Electrode Modified with Self‐Assembled Monolayer of Cysteamine‐Functionalized MWCNT and Its Application in Simultaneous Determination of Dopamine and Uric Acid
Authors: Shahrokhian Saeed , Mahdavi‐Shakib Akbar , Ghalkhani Masoumeh , Saberi Reihaneh‐sadat 
Published: January 2012

AbstractThe voltammetric behavior of dopamine (DA) and uric acid (UA) on a gold electrode modified with self‐assembled monolayer (SAM) of cysteamine (CA) conjugated with functionalized multiwalled carbon nanotubes (MWCNTs) was investigated. The film modifier of functionalized SAM was characterized by means of scanning electron microscopy (SEM) and also, electrochemical impedance spectroscopy (EIS) using para‐hydroquinone (PHQ) as a redox probe. For the binary mixture of DA and UA, the voltammetric signals of these two compounds can be well separated from each other, allowing simultaneous determination of DA and UA. The effect of various experimental parameters on the voltammetric responses of DA and UA was investigated. The detection limit in differential pulse voltammetric determinations was obtained as 0.02 µM and 0.1 µM for DA and UA, respectively. The prepared modified electrode indicated a stable behavior and the presence of surface COOH groups of the functionalized MWCNT avoided the passivation of the electrode surface during the electrode processes. The proposed method was successfully applied for the determination of DA and UA in urine samples with satisfactory results. The response of the gold electrode modified with MWCNT‐functionalized SAM method toward DA, UA, and ascorbic acid (AA) oxidation was compared with the response of the modified electrode prepared by the direct casting of MWCNT.
DNA damage profiles induced by sunlight at different latitudes
Authors: Schuch André Passaglia , Yagura Teiti , Makita Kazuo , Yamamoto Hiromasa , Schuch Nelson Jorge , Agnez‐Lima Lucymara Fassarella , MacMahon Ricardo Monreal , Menck Carlos Frederico Martins 
Published: January 2012

AbstractDespite growing knowledge on the biological effects of ultraviolet (UV) radiation on human health and ecosystems, it is still difficult to predict the negative impacts of the increasing incidence of solar UV radiation in a scenario of global warming and climate changes. Hence, the development and application of DNA‐based biological sensors to monitor the solar UV radiation under different environmental conditions is of increasing importance. With a mind to rendering a molecular view‐point of the genotoxic impact of sunlight, field experiments were undertaken with a DNA‐dosimeter system in parallel with physical photometry of solar UVB/UVA radiation, at various latitudes in South America. Onapplying biochemical and immunological approaches based on specific DNA‐repair enzymes and antibodies, for evaluating sunlight‐induced DNA damage profiles, it became clear that the genotoxic potential of sunlight does indeed vary according to latitude. Notwithstanding, while induction of oxidized DNA bases is directly dependent on an increase in latitude, the generation of 6‐4PPs is inversely so, whereby the latter can be regarded as a biomolecular marker of UVB incidence. This molecular DNA lesion‐pattern largely reflects the relative incidence of UVA and UVB energy at any specific latitude. Hereby is demonstrated the applicability of this DNA‐based biosensor for additional, continuous field experiments, as a means of registering variations in the genotoxic impact of solar UV radiation. Environ. Mol. Mutagen. 2012. © 2012 Wiley Periodicals, Inc.
International Evidence on GFC‐Robust Forecasts for Risk Management under the Basel Accord
Authors: McAleer Michael , Jiménez‐Martín Juan‐Ángel , Pérez‐Amaral Teodosio 
Published: January 2012

ABSTRACTA risk management strategy designed to be robust to the global financial crisis (GFC), in the sense of selecting a value‐at‐risk (VaR) forecast that combines the forecasts of different VaR models, was proposed by McAleer and coworkers in 2010. The robust forecast is based on the median of the point VaR forecasts of a set of conditional volatility models. Such a risk management strategy is robust to the GFC in the sense that, while maintaining the same risk management strategy before, during and after a financial crisis, it will lead to comparatively low daily capital charges and violation penalties for the entire period. This paper presents evidence to support the claim that the median point forecast of VaR is generally GFC robust. We investigate the performance of a variety of single and combined VaR forecasts in terms of daily capital requirements and violation penalties under the Basel II Accord, as well as other criteria. In the empirical analysis we choose several major indexes, namely French CAC, German DAX, US Dow Jones, UK FTSE100, Hong Kong Hang Seng, Spanish Ibex 35, Japanese Nikkei, Swiss SMI and US S&P 500. The GARCH, EGARCH, GJR and RiskMetrics models as well as several other strategies, are used in the comparison. Backtesting is performed on each of these indexes using the Basel II Accord regulations for 2008–10 to examine the performance of the median strategy in terms of the number of violations and daily capital charges, among other criteria. The median is shown to be a profitable and safe strategy for risk management, both in calm and turbulent periods, as it provides a reasonable number of violations and daily capital charges. The median also performs well when both total losses and the asymmetric linear tick loss function are considered Copyright © 2012 John Wiley & Sons, Ltd.
Shrinkage‐Based Tests of Predictability
Authors: Brown Pablo Matias Pincheira 
Published: January 2012

ABSTRACTIn this paper we derive a test of predictability by exploring the possibility that forecasts from a given model, adjusted by a shrinkage factor, will display lower mean squared prediction errors than forecasts from a simple random walk. This generalizes most previous tests which compare forecast errors of a benchmark model with errors of a proposed alternative model, not allowing for shrinkage. We show that our test is a particular extension of a recently developed test of the martingale difference hypothesis. Using simulations we explore the behavior of our test in small and moderate samples. Numerical results indicate that the test has good size and power properties. Finally, we illustrate the use of our test in an empirical application within the exchange rate literature. Copyright © 2012 John Wiley & Sons, Ltd.
Probing tissue microstructure with restriction spectrum imaging: Histological and theoretical validation
Authors: White Nathan S. , Leergaard Trygve B. , D'Arceuil Helen , Bjaalie Jan G. , Dale Anders M. 
Published: January 2012

AbstractWater diffusion magnetic resonance imaging (dMRI) is a powerful tool for studying biological tissue microarchitectures in vivo. Recently, there has been increased effort to develop quantitative dMRI methods to probe both length scale and orientation information in diffusion media. Diffusion spectrum imaging (DSI) is one such approach that aims to resolve such information based on the three‐dimensional diffusion propagator at each voxel. However, in practice, only the orientation component of the propagator function is preserved when deriving the orientation distribution function. Here, we demonstrate how a straightforward extension of the linear spherical deconvolution (SD) model can be used to probe tissue orientation structures over a range (or “spectrum”) of length scales with minimal assumptions on the underlying microarchitecture. Using high b‐value Cartesian q‐space data on a rat brain tissue sample, we demonstrate how this “restriction spectrum imaging” (RSI) model allows for separating the volume fraction and orientation distribution of hindered and restricted diffusion, which we argue stems primarily from diffusion in the extraneurite and intraneurite water compartment, respectively. Moreover, we demonstrate how empirical RSI estimates of the neurite orientation distribution and volume fraction capture important additional structure not afforded by traditional DSI or fixed‐scale SD‐like reconstructions, particularly in gray matter. We conclude that incorporating length scale information in geometric models of diffusion offers promise for advancing state‐of‐the‐art dMRI methods beyond white matter into gray matter structures while allowing more detailed quantitative characterization of water compartmentalization and histoarchitecture of healthy and diseased tissue. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Brain functional connectivity of male patients in remission after the first episode of schizophrenia
Authors: Kasparek Tomas , Prikryl Radovan , Rehulova Jitka , Marecek Radek , Mikl Michal , Prikrylova Hana , Vanicek Jiri , Ceskova Eva 
Published: January 2012

AbstractObjectives: Abnormal task‐related activation and connectivity is present in schizophrenia. The aim of this study was the analysis of functional networks in schizophrenia patients in remission after the first episode. Experimental design: Twenty‐nine male patients in remission after the first episode of schizophrenia and 22 healthy controls underwent examination by functional magnetic resonance during verbal fluency tasks (VFT). The functional connectivity of brain networks was analyzed using independent component analysis. Results: The patients showed lower activation of the salience network during VFT. They also showed lower deactivation of the default mode network (DMN) during VFT processing. Spectral analysis of the component time courses showed decreased power in slow frequencies of signal fluctuations in the salience and DMNs and increased power in higher frequencies in the left frontoparietal cortex reflecting higher fluctuations of the network activity. Moreover, there was decreased similarity of component time courses in schizophrenia—the patients had smaller negative correlation between VFT activated and deactivated networks, and smaller positive correlations between DMN subcomponents. Conclusions: There is still an abnormal functional connectivity of several brain networks in remission after the first episode of schizophrenia. The effect of different treatment modalities on brain connectivity, together with temporal dynamics of this functional abnormality should be the objective of further studies to assess its potential as a marker of disease stabilization. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
A generalized procedure for calibrated MRI incorporating hyperoxia and hypercapnia
Authors: Gauthier Claudine J. , Hoge Richard D. 
Published: January 2012

AbstractCalibrated MRI techniques use the changes in cerebral blood flow (CBF) and blood oxygenation level‐dependent (BOLD) signal evoked by a respiratory manipulation to extrapolate the total BOLD signal attributable to deoxyhemoglobin at rest (M). This parameter can then be used to estimate changes in the cerebral metabolic rate of oxygen consumption (CMRO2) based on task‐induced BOLD and CBF signals. Different approaches have been described previously, including addition of inspired CO2 (hypercapnia) or supplemental O2 (hyperoxia). We present here a generalized BOLD signal model that reduces under appropriate conditions to previous models derived for hypercapnia or hyperoxia alone, and is suitable for use during hybrid breathing manipulations including simultaneous hypercapnia and hyperoxia. This new approach yields robust and accurate M maps, in turn allowing more reliable estimation of CMRO2 changes evoked during a visual task. The generalized model is valid for arbitrary flow changes during hyperoxia, thus benefiting from the larger total oxygenation changes produced by increased blood O2 content from hyperoxia combined with increases in flow from hypercapnia. This in turn reduces the degree of extrapolation required to estimate M. The new procedure yielded M estimates that were generally higher (7.6 ± 2.6) than those obtained through hypercapnia (5.6 ± 1.8) or hyperoxia alone (4.5 ± 1.5) in visual areas. These M values and their spatial distribution represent a more accurate and robust depiction of the underlying distribution of tissue deoxyhemoglobin at rest, resulting in more accurate estimates of evoked CMRO2 changes. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Decoding abstract and concrete concept representations based on single‐trial fMRI data
Authors: Wang Jing , Baucom Laura B. , Shinkareva Svetlana V. 
Published: January 2012

AbstractPreviously, multi‐voxel pattern analysis has been used to decode words referring to concrete object categories. In this study we investigated if single‐trial‐based brain activity was sufficient to distinguish abstract (e.g., mercy) versus concrete (e.g., barn) concept representations. Multiple neuroimaging studies have identified differences in the processing of abstract versus concrete concepts based on the averaged activity across time by using univariate methods. In this study we used multi‐voxel pattern analysis to decode functional magnetic resonance imaging (fMRI) data when participants perform a semantic similarity judgment task on triplets of either abstract or concrete words with similar meanings. Classifiers were trained to identify individual trials as concrete or abstract. Cross‐validated accuracies for classifying trials as abstract or concrete were significantly above chance (P < 0.05) for all participants. Discriminating information was distributed in multiple brain regions. Moreover, accuracy of identifying single trial data for any one participant as abstract or concrete was also reliably above chance (P < 0.05) when the classifier was trained solely on data from other participants. These results suggest abstract and concrete concepts differ in representations in terms of neural activity patterns during a short period of time across the whole brain. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
The neural substrate for working memory of tactile surface texture
Authors: Kaas Amanda L. , van Mier Hanneke , Visser Maya , Goebel Rainer 
Published: January 2012

AbstractFine surface texture is best discriminated by touch, in contrast to macro geometric features like shape. We used functional magnetic resonance imaging and a delayed match‐to‐sample task to investigate the neural substrate for working memory of tactile surface texture. Blindfolded right‐handed males encoded the texture or location of up to four sandpaper stimuli using the dominant or non‐dominant hand. They maintained the information for 10–12 s and then answered whether a probe stimulus matched the memory array. Analyses of variance with the factors Hand, Task, and Load were performed on the estimated percent signal change for the encoding and delay phase. During encoding, contralateral effects of Hand were found in sensorimotor regions, whereas Load effects were observed in bilateral postcentral sulcus (BA2), secondary somatosensory cortex (S2), pre‐SMA, dorsolateral prefrontal cortex (dlPFC), and superior parietal lobule (SPL). During encoding and delay, Task effects (texture > location) were found in central sulcus, S2, pre‐SMA, dlPFC, and SPL. The Task and Load effects found in hand‐ and modality‐specific regions BA2 and S2 indicate involvement of these regions in the tactile encoding and maintenance of fine surface textures. Similar effects in hand‐ and modality‐unspecific areas dlPFC, pre‐SMA and SPL suggest that these regions contribute to the cognitive monitoring required to encode and maintain multiple items. Our findings stress both the particular importance of S2 for the encoding and maintenance of tactile surface texture, as well as the supramodal nature of parieto‐frontal networks involved in cognitive control. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Letters persistence after physical offset: Visual word form area and left planum temporale. An fMRI study
Authors: Barban Francesco , Daniele Zannino Gian , Macaluso Emiliano , Caltagirone Carlo , Carlesimo Giovanni A. 
Published: January 2012

AbstractIconic memory is a high‐capacity low‐duration visual memory store that allows the persistence of a visual stimulus after its offset. The categorical nature of this store has been extensively debated. This study provides functional magnetic resonance imaging evidence for brain regions underlying the persistence of postcategorical representations of visual stimuli. In a partial report paradigm, subjects matched a cued row of a 3 × 3 array of letters (postcategorical stimuli) or false fonts (precategorical stimuli) with a subsequent triplet of stimuli. The cued row was indicated by two visual flankers presented at the onset (physical stimulus readout) or after the offset of the array (iconic memory readout). The left planum temporale showed a greater modulation of the source of readout (iconic memory vs. physical stimulus) when letters were presented compared to false fonts. This is a multimodal brain region responsible for matching incoming acoustic and visual patterns with acoustic pattern templates. These findings suggest that letters persist after their physical offset in an abstract postcategorical representation. A targeted region of interest analysis revealed a similar pattern of activation in the Visual Word Form Area. These results suggest that multiple higher‐order visual areas mediate iconic memory for postcategorical stimuli. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Prescription profiles for pharmacological treatment of Japanese inpatients with schizophrenia: comparison between 2007 and 2009
Authors: Yoshio Takashi , Inada Toshiya , Uno Junji , Miwa Takaichi , Kitagawa Kohei , Miyahara Yoshiki , Umeda Kenta , Kato Tsuyoshi , Inagaki Ataru , Nabeshima Toshitaka 
Published: January 2012

Background and ObjectivePharmacological treatment of schizophrenic patients in Japan is characterized by polypharmacy with high doses of antipsychotics. In this study, we examined the profiles of antipsychotic drug therapy in 2007 and 2009 to determine if there have been any recent shifts in treatment strategy.MethodThe subjects were schizophrenic inpatients (ICD‐10‐F20) admitted to 100 hospitals in 2007 and 152 hospitals in 2009. Information on the psychotropic agents prescribed on specified days in November 2007 and 2009 was acquired for each patient.ResultsAlthough no changes were observed in the rate of antipsychotic medications being prescribed, the rate of antipsychotic monotherapy in 2009 increased significantly. In 2007, among 15,761 patients, 4977 (31.6%) received antipsychotic monotherapy (i.e., administration of a single antipsychotic medication). In 2009, among 22,911 patients, 7741 (33.8%) received antipsychotic monotherapy.ConclusionThe rate of use of antipsychotic monotherapy has gradually increased, although the total dose has not changed significantly. The increase in the concomitant use of two or more second‐generation antipsychotics is a recent trend in Japan, despite the lack of information on the efficacy and safety of this treatment strategy. Copyright © 2012 John Wiley & Sons, Ltd.
Temporal Granger Causality and the Dynamics Relationship Between Real Tourism Receipts, Real Income and Real Exchange Rates in Malaysia
Authors: Tang Chor Foon 
Published: January 2012

ABSTRACTThis study applies the bounds testing approach, error‐correction modelling and persistence profile to analyse the dynamic relationship between real tourism receipts, real income and real exchange rates in Malaysia. The present study covers the annual sample period from 1974 to 2009. The results reveal that a long‐run relationship exists between the variables. In the short run, this study finds no Granger causality between real tourism receipts and real income, whereas there is bidirectional causality in the long‐run. Moreover, we also find unidirectional causality running from real exchange rates to real tourism receipts and real income in both short‐ and long‐run. Copyright © 2012 John Wiley & Sons, Ltd.
Prostate‐Cancer‐Targeted N‐(2‐Hydroxypropyl)methacrylamide Copolymer/Docetaxel Conjugates
Authors: Liu Jihua , Kopečková Pavla , Pan Huaizhong , Sima Monika , Bühler Patrick , Wolf Philipp , Elsässer‐Beile Ursula , Kopeček Jindřich 
Published: January 2012

AbstractBiodistribution, pharmacokinetics, and efficacy of prostate‐cancer‐targeted HPMA copolymer/DTX conjugates are evaluated in nude mice bearing prostate cancer C4‐2 xenografts. PSMA‐specific monoclonal antibodies 3F/11 are used as the targeting moiety. Control conjugates contain either non‐specific IgG or no IgG. The ratios of tumor accumulation to total background organs (heart, lung, kidney, liver, spleen and blood) accumulation increase substantially with time for the targeted conjugate, and the ratio at 48 h is 7‐fold higher than that at 6 h. Preliminary evaluation of the efficacy of the conjugates in vivo show tumor growth inhibition for all HPMA copolymer/DTX conjugates.magnified image
Injectable Hydrogel for Sustained Protein Release by Salt‐Induced Association of Hyaluronic Acid Nanogel
Authors: Nakai Takashi , Hirakura Tai , Sakurai Yuji , Shimoboji Tsuyoshi , Ishigai Masaki , Akiyoshi Kazunari 
Published: January 2012

AbstractA hyaluronic acid‐based anionic nanogel formed by self‐assembly of cholesteryl‐group‐bearing HA is designed for protein delivery. The HA nanogel spontaneously binds various types of proteins without denaturation, such as recombinant human growth hormone, erythropoietin, exendin‐4, and lysozyme. The HA nanogel shows unique colloidal properties, in particular that an injectable hydrogel is formed by salt‐induced association of the HA nanogel. A pharmacokinetic study in rats shows that an in situ gel formulation, prepared by simply mixing rhGH and HA nanogel in phosphate buffer, maintains plasma rhGH levels within a narrow range over one week. Therefore, HA nanogels offer a simple method for easy formulation of therapeutic proteins and are effective for sustained protein release systems.magnified image
The Korean Version of the Connor–Davidson Resilience Scale: An Extended Validation
Authors: Jung Young‐Eun , Min Jung‐Ah , Shin A Young , Han Su Yeon , Lee Kyoung‐Uk , Kim Tae‐Suk , Park Joo‐Eon , Choi Sam‐Wook , Lee Seung‐Hwan , Choi Kyeong Sook , Park Young Min , Woo Jong‐Min , Bhang Soo‐Young , Kang Eun‐Ho , Kim Won , Yu Jeong Jin , Chae Jeong‐Ho ,   Positiveness Research Team of Korea
Published: January 2012

AbstractThe Connor–Davidson Resilience Scale (CD‐RISC) is a brief self‐rating questionnaire for measuring resilience. The aims of the present study were to describe the development of a Korean version of the CD‐RISC (K‐CD‐RISC) and to more firmly establish its psychometric properties in terms of reliability and validity. The participants consisted of a general population sample (n = 194) and psychiatric outpatients (n = 127) with non‐psychotic mood or anxiety disorders. The K‐CD‐RISC score means (standard deviation) were 65.9 (13.6) in the general population and 50.4 (20.5) in the psychiatric outpatients. The mean score of the general population was significantly higher than that of the psychiatric outpatients. Exploratory factor analysis revealed five factors, and the obtained factor structure was verified through confirmatory factor analysis. In the general population, the Cronbach's α coefficient of the K‐CD‐RISC was found to be 0.92. Greater resilience was found to be associated with less perceived stress, anxiety and depression and with higher levels of positive affect and purpose in life. Taken together, our findings suggest that the K‐CD‐RISC has good psychometric properties and is a valid and reliable tool for assessing resilience. Copyright © 2012 John Wiley & Sons, Ltd.