bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional connectivity‐based identification of subdivisions of the basal ganglia and thalamus using multilevel independent component analysis of resting state fMRI
Authors: Kim Dae‐Jin , Park Bumhee , Park Hae‐Jeong 
Published: February 2012

AbstractThis study aimed to identify subunits of the basal ganglia and thalamus and to investigate the functional connectivity among these anatomically segregated subdivisions and the cerebral cortex in healthy subjects. For this purpose, we introduced multilevel independent component analysis (ICA) of the resting‐state functional magnetic resonance imaging (fMRI). After applying ICA to the whole brain gray matter, we applied second‐level ICA restrictively to the basal ganglia and the thalamus area to identify discrete functional subunits of those regions. As a result, the basal ganglia and the thalamus were parcelled into 31 functional subdivisions according to their temporal activity patterns. The extracted parcels showed functional network connectivity between hemispheres, between subdivisions of the basal ganglia and thalamus, and between the extracted subdivisions and cerebral functional components. Grossly, these findings correspond to cortico‐striato‐thalamo‐cortical circuits in the brain. This study also showed the utility of multilevel ICA of resting state fMRI in brain network research. Hum Brain Mapp, 2013. © 2012 Wiley Perodicals, Inc.
Adaptive changes in the neuromagnetic response of the primary and association somatosensory areas following repetitive tactile hand stimulation in humans
Authors: Popescu Elena Anda , Barlow Steven M. , Venkatesan Lalit , Wang Jingyan , Popescu Mihai 
Published: February 2012

AbstractCortical adaptation in the primary somatosensory cortex (SI) has been probed using different stimulation modalities and recording techniques, in both human and animal studies. In contrast, considerably less knowledge has been gained about the adaptation profiles in other areas of the cortical somatosensory network. Using magnetoencephalography (MEG), we examined the patterns of short‐term adaptation for evoked responses in SI and somatosensory association areas during tactile stimulation applied to the glabrous skin of the hand. Cutaneous stimuli were delivered as trains of serial pulses with a constant frequency of 2 Hz and 4 Hz in separate runs, and a constant inter‐train interval of 5 s. The unilateral stimuli elicited transient responses to the serial pulses in the train, with several response components that were separated by independent component analysis. Subsequent source reconstruction techniques identified regional generators in the contralateral SI and somatosensory association areas in the posterior parietal cortex (PPC). Activity in the bilateral secondary somatosensory cortex (i.e., SII/PV) was also identified, although less consistently across subjects. The dynamics of the evoked activity in each area and the frequency‐dependent adaptation effects were assessed from the changes in the relative amplitude of serial responses in each train. We show that the adaptation profiles in SI and PPC areas can be quantitatively characterized from neuromagnetic recordings using tactile stimulation, with the sensitivity to repetitive stimulation increasing from SI to PPC. A similar approach for SII/PV has proven less straightforward, potentially due to the tendency of these areas to respond selectively to certain stimuli. Hum Brain Mapp, 2013. © 2012 Wiley Perodicals, Inc.
Resting state cortical electroencephalographic rhythms are related to gray matter volume in subjects with mild cognitive impairment and Alzheimer's disease
Authors: Babiloni Claudio , Carducci Filippo , Lizio Roberta , Vecchio Fabrizio , Baglieri Annalisa , Bernardini Silvia , Cavedo Enrica , Bozzao Alessandro , Buttinelli Carla , Esposito Fabrizio , Giubilei Franco , Guizzaro Antonio , Marino Silvia , Montella Patrizia , Quattrocchi Carlo C. , Redolfi Alberto , Soricelli Andrea , Tedeschi Gioacchino , Ferri Raffaele , Rossi‐Fedele Giancarlo , Ursini Francesca , Scrascia Federica , Vernieri Fabrizio , Pedersen Torleif Jan , Hardemark Hans‐Goran , Rossini Paolo M. , Frisoni Giovanni B. 
Published: February 2012

AbstractCortical gray matter volume and resting state cortical electroencephalographic rhythms are typically abnormal in subjects with amnesic mild cognitive impairment (MCI) and Alzheimer's disease (AD). Here we tested the hypothesis that in amnesic MCI and AD subjects, abnormalities of EEG rhythms are a functional reflection of cortical atrophy across the disease. Eyes‐closed resting state EEG data were recorded in 57 healthy elderly (Nold), 102 amnesic MCI, and 108 AD patients. Cortical gray matter volume was indexed by magnetic resonance imaging recorded in the MCI and AD subjects according to Alzheimer's disease neuroimaging initiative project (http://www.adni‐info.org/). EEG rhythms of interest were delta (2–4 Hz), theta (4–8 Hz), alpha1 (8–10.5 Hz), alpha2 (10.5–13 Hz), beta1 (13–20 Hz), beta2 (20–30 Hz), and gamma (30–40 Hz). These rhythms were indexed by LORETA. Compared with the Nold, the MCI showed a decrease in amplitude of alpha 1 sources. With respect to the Nold and MCI, the AD showed an amplitude increase of delta sources, along with a strong amplitude reduction of alpha 1 sources. In the MCI and AD subjects as a whole group, the lower the cortical gray matter volume, the higher the delta sources, the lower the alpha 1 sources. The better the score to cognitive tests the higher the gray matter volume, the lower the pathological delta sources, and the higher the alpha sources. These results suggest that in amnesic MCI and AD subjects, abnormalities of resting state cortical EEG rhythms are not epiphenomena but are strictly related to neurodegeneration (atrophy of cortical gray matter) and cognition. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Prefrontal dopaminergic receptor abnormalities and executive functions in Parkinson's disease
Authors: Ko Ji Hyun , Antonelli Francesca , Monchi Oury , Ray Nicola , Rusjan Pablo , Houle Sylvain , Lang Anthony E. , Christopher Leigh , Strafella Antonio P. 
Published: February 2012

AbstractThe main pattern of cognitive impairments seen in early to moderate stages of Parkinson's disease (PD) includes deficits of executive functions. These nonmotor complications have a significant impact on the quality of life and day‐to‐day activities of PD patients and are not effectively managed by current therapies, a problem which is almost certainly due to the fact that the disease extends beyond the nigrostriatal system. To investigate the role of extrastriatal dopamine in executive function in PD, PD patients and a control group were studied with positron‐emission‐tomography using a high‐affinity dopamine D2/D3 receptor tracer, [11C]FLB‐457. All participants were scanned twice while performing an executive task and a control task. Patients were off medication for at least 12 h. The imaging analysis revealed that parkinsonian patients had lower [11C]FLB‐457 binding than control group independently of task conditions across different brain regions. Cognitive assessment measures were positively correlated with [11C]FLB‐457 binding in the bilateral dorsolateral prefrontal cortex and anterior cingulate cortex only in control group, but not in PD patients. Within the control group, during the executive task (as compared to control task), there was evidence of reduced [11C]FLB‐457 binding (indicative of increased dopamine release) in the right orbitofrontal cortex. In contrast, PD patients did not show any reduction in binding during the executive task (as compared with control task). These findings suggest that PD patients present significant abnormalities in extrastriatal dopamine associated with executive processing. These observations provide important insights on the pathophysiology of cognitive dysfunction in PD. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
The dynamics of change in striatal activity following updating training
Authors: Kühn Simone , Schmiedek Florian , Noack Hannes , Wenger Elisabeth , Bodammer Nils C. , Lindenberger Ulman , Lövden Martin 
Published: February 2012

AbstractIncreases in striatal activity have been suggested to mediate training‐related improvements in working‐memory ability. We investigated the temporal dynamics of changes in task‐related brain activity following training of working memory. Participants in an experimental group and an active control group, trained on easier tasks of a constant difficulty in shorter sessions than the experimental group, were measured before, after about 1 week, and after more than 50 days of training. In the experimental group an initial increase of working‐memory related activity in the functionally defined right striatum and anatomically defined right and left putamen was followed by decreases, resulting in an inverted u‐shape function that relates activity to training over time. Activity increases in the striatum developed slower in the active control group, observed at the second posttest after more than 50 days of training. In the functionally defined left striatum, initial activity increases were maintained after more extensive training and the pattern was similar for the two groups. These results shed new light on the relation between activity in the striatum (especially the putamen) and the effects of working memory training, and illustrate the importance of multiple measurements for interpreting effects of training on regional brain activity. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Practical application of product design method robust to disturbances
Authors: Mrugalska Beata , Kawecka‐Endler Aleksandra 
Published: February 2012

AbstractContemporary designed and manufactured products should meet a wide range of client requirements and expectations regarding quality for conditions of use in a life cycle. Therefore, design methods, which enable an optimal choice of product parameters by decreasing product sensivity to occurrence of some disturbances in a manufacturing process, become more and more significant in industrial practice. Such a behavior probably allows getting the lowest quality loss while keeping planned production costs. In this article, a new method of products design robust to disturbances exsisting in a technological process is presented. The application of mathematical modeling and methods of parameter estimation enabled formulating an approach in which parameters and acceptable tolerance of manufacturing product parameters are calculated. The efficiency of the proposed method was verified in the machine‐building industry with the example of designing parameters of a brushless direct current motor. © 2010 Wiley Periodicals, Inc.
Data‐based analysis of bivariate copula tail dependence for drought duration and severity
Authors: Lee T. , Modarres R. , Ouarda T. B. M. J. 
Published: February 2012

AbstractIn recent decades, copula functions have been applied in bivariate drought duration and severity frequency analysis. Among several potential copulas, Clayton has been mostly used in drought analysis. In this research, we studied the influence of the tail shape of various copula functions (i.e. Gumbel, Frank, Clayton and Gaussian) on drought bivariate frequency analysis. The appropriateness of Clayton copula for the characterization of drought characteristics is also investigated. Drought data are extracted from standardized precipitation index time series for four stations in Canada (La Tuque and Grande Prairie) and Iran (Anzali and Zahedan). Both duration and severity data sets are positively skewed. Different marginal distributions were first fitted to drought duration and severity data. The gamma and exponential distributions were selected for drought duration and severity, respectively, according to the positive skewness and Kolmogorov–Smirnov test. The results of copula modelling show that the Clayton copula function is not an appropriate choice for the used data sets in the current study and does not give more drought risk information than an independent model for which the duration and severity dependence is not significant. The reason is that the dependence of two variables in the upper tail of Clayton copula is very weak and similar to the independent case, whereas the observed data in the transformed domain of cumulative density function show high association in the upper tail. Instead, the Frank and Gumbel copula functions show better performance than Clayton function for drought bivariate frequency analysis. Copyright © 2012 John Wiley & Sons, Ltd.
The hydrogeomorphic influences on alluvial gully erosion along the Mitchell River fluvial megafan
Authors: Shellberg J. G. , Brooks A. P. , Spencer J. , Ward D. 
Published: February 2012

AbstractHydrogeomorphic processes influencing alluvial gully erosion were evaluated at multiple spatial and temporal scales across the Mitchell River fluvial megafan in tropical Queensland, Australia. Longitudinal changes in floodplain inundation were quantified using river gauge data, local stage recorders and HEC‐RAS modelling based on LiDAR topographic data. Intra‐ and interannual gully scarp retreat rates were measured using daily time‐lapse photographs and annual GPS surveys. Erosion was analysed in response to different water sources and associated erosion processes across the floodplain perirheic zone, including direct rainfall, infiltration‐excess runoff, soil‐water seepage, river backwater and overbank flood inundation. The frequency of river flood inundation of alluvial gullies changed longitudinally according to river incision and confinement. Near the top of the megafan, flood water was contained within the macrochannel up to the 100‐year recurrence interval, but river backwater still partially inundated adjacent gullies eroding into Pleistocene alluvium. In downstream Holocene floodplains, inundation of alluvial gullies occurred beyond the 2‐ to 5‐year recurrence interval and contributed significantly to total annual erosion. However, most gully scarp retreat at all sites was driven by direct rainfall and infiltration‐excess runoff, with the 24‐h rainfall total being the most predictive variable. The remaining variability can be explained by seasonal vegetative conditions, complex cycles of soil wetting and drying, tension crack development, near‐surface pore‐water pressure, soil block undermining from spalling and overland flow, and soil property heterogeneity. Implications for grazing management impacts on soil surface and perennial grass conditions include effects on direct rainfall erosion, water infiltration, runoff volume, water concentration along tracks, and the resistance of highly dispersible soils to gully initiation or propagation under intense tropical rainfall. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of Planar Chiral Carbazole Derivatives Bearing a [2.2]Paracyclophane Skeleton
Authors: Lennartz Petra , Raabe Gerhard , Bolm Carsten 
Published: February 2012

AbstractThe synthesis of planar chiral carbazoles bearing a [2.2]paracyclophane backbone is described. Starting from readily available 4‐bromo[2.2]paracyclophane planar chiral carbazoles are obtained in a two‐step synthesis by Pd‐catalyzed CN cross‐coupling and subsequent oxidative cyclization.
Aryl[2.2]paracyclophane‐Based Chiral Regioisomeric Analogs of Salicyl Aldehyde: Novel Sources for Construction of Phenoxy‐Imine Ligands
Authors: Zhuravsky Roman P. , Danilova Tatiana I. , Antonov Dmitrii Yu. , Sergeeva Elena V. , Starikova Zoya A. , Godovikov Ivan A. , Il'in Michail M. , Rozenberg Valeria I. 
Published: February 2012

AbstractThe efficient, high‐yield approaches to two novel regioisomeric salicyl aldehyde analogs, 4‐formyl‐13‐(2‐hydroxyphenyl)‐[2.2]paracyclophane and 4‐formyl‐12‐(2‐hydroxyphenyl)‐[2.2]paracyclophane (iso‐FHPhPC and pseudo‐FHPhPC, respectively), constructed on the basis of an aryl[2.2]paracyclophane backbone are described. The key stage of the backbone formation is the Suzuki cross‐coupling of paracyclophanyl halides with arylboronic acids. Efficient procedures for the resolution of the racemic hydroxy aldehydes into enantiomers via Schiff bases with enantiomers of α‐phenylethyl amine were elaborated, and the absolute configurations of enantiomers were established on the basis of X‐ray analysis of diastereomeric imines. Starting from these chiral hydroxy aldehydes the first representatives of bi‐, tri‐, and tetradentate phenoxy‐imine ligands belonging to an aryl[2.2]paracyclophane family were obtained. The induction power of the ligands was tested in the Et2Zn asymmetric addition to aldehydes.
Improving fMRI activation detection sensitivity using intervoxel coherence mapping
Authors: Wang Ze , Li Zhengjun , Pluta John , Detre John A. 
Published: February 2012

AbstractSpatiotemporal data coherence widely exists in fMRI data and can be potentially used to increase brain activation detection. To assess this possibility, a two‐stage fMRI data analysis method was presented in this work. Standard voxelwise general linear model (GLM) was used to first exclude voxels with low correlation to the functional design, and an intervoxel coherence map (ICM) was then calculated voxel by voxel to locate brain regions, which were most consistently activated during the functional experiment. Population inference about the detected effects was provided through random effect analysis or permutation testing. Evaluations using synthetic data and scene‐encoding memory task fMRI data both showed enhanced activation detection performance for the proposed method when compared with standard GLM. © 2012 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 22, 33–36, 2012
Improving the accuracy of cross‐relaxation imaging
Authors: Stikov Nikola 
Published: February 2012

AbstractCross‐relaxation imaging (CRI) provides biomarkers sensitive to the macromolecular content of tissue. Although the CRI parameters are sufficiently precise to exhibit significant correlations with macromolecular content in tissue, their accuracy is hindered by the CRI modeling and measurement variability. In this article, several sources of CRI variability are examined, such as T1 mapping bias, magnetization transfer signal drift, and inaccuracies due to tissue modeling. Simple corrections schemes are proposed to account for these effects and to improve the CRI accuracy. © 2012 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 22, 67–72, 2012
Cytotoxicity of dioscin in human gastric carcinoma cells through death receptor and mitochondrial pathways
Authors: Hu Mingming , Xu Lina , Yin Lianhong , Qi Yan , Li Hua , Xu Youwei , Han Xu , Peng Jinyong , Wan Xianyao 
Published: February 2012

ABSTRACTIn the present study, the antiproliferative effect of dioscin on human gastric carcinoma SGC‐7901 cells was confirmed by 3‐(4, 5‐dimethylthiahiazo‐zyl)‐2, 5‐dip‐henytetrazolium bromide and flow cytometry assays. Through acridine orange–ethidium bromide double fluorescent staining, apoptotic morphology of the cells was observed. Radioimmunoassays showed that the tumor necrosis factor (TNF)‐α concentration in cells treated with dioscin significantly increased compared with untreated cells. Several proteins and mRNA related to the mitochondrial and death receptor pathways were investigated. We found that the expression of Bid, bcl‐2 and bcl‐xl was markedly downregulated, and the expression of Bak and Bax was upregulated. In addition, cytochrome c was released from the mitochondria into the cytosol, which indicates activation of the mitrochondrial pathway by dioscin. Furthermore, upregulation of Fas, FasL (Fas ligand), TNF‐α, TNF receptor‐1, TNF receptor‐associated factor 1 and Fas‐associated protein with death domain demonstrated involvement of the death receptor pathway. Increased mRNA expression of p53 was also found in dioscin‐treated SGC‐7901 cells, and the activation of caspase‐3 and −8 was also observed. Consequently, this study clarifies the mechanism underlying the anticancer effect of dioscin, and also indicates that dioscin may be a potential drug treatment for human gastric cancer. Copyright © 2012 John Wiley & Sons, Ltd.
Stress shielding and fatigue limits of poly‐ether‐ether‐ketone dental implants
Authors: Lee Woo‐Taek , Koak Jai‐Young , Lim Young‐Jun , Kim Seong‐Kyun , Kwon Ho‐Beom , Kim Myung‐Joo 
Published: February 2012

AbstractThe poly‐ether‐ether‐ketone (PEEK) polymer is of great interest as an alternative to titanium in orthopedics because of its biocompatibility and low elastic modulus. This study evaluated the fatigue limits of PEEK and the effects of the low elastic modulus PEEK in relation to existing dental implants. Compressive loading tests were performed with glass fiber‐reinforced PEEK (GFR‐PEEK), carbon fiber‐reinforced PEEK (CFR‐PEEK), and titanium rods. Among these tests, GFR‐PEEK fatigue tests were performed according to ISO 14801. For the finite element analysis, three‐dimensional models of dental implants and bone were constructed. The implants in the test groups were coated with a 0.5‐mm thick and 5‐mm long PEEK layer on the upper intrabony area. The strain energy densities (SED) were calculated, and the bone resorption was predicted. The fatigue limits of GFR‐PEEK were 310 N and were higher than the static compressive strength of GFR‐PEEK. The bone around PEEK‐coated implants showed higher levels of SED than the bone in direct contact with the implants, and the wider diameter and stiffer implants showed lower levels of SED. The compressive strength of the GFR‐PEEK and CFR‐PEEK implants ranged within the bite force of the anterior and posterior dentitions, respectively, and the PEEK implants showed adequate fatigue limits for replacing the anterior teeth. Dental implants with PEEK coatings and PEEK implants may reduce stress shielding effects. Dental implant application of PEEK polymer—fatigue limit and stress shielding. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012
Development of a probucol‐releasing antithrombogenic drug eluting stent
Authors: Vedantham Kumar , Chaterji Somali , Kim Sung Won , Park Kinam 
Published: February 2012

AbstractThe success of drug eluting stents (DESs) has been challenged by the manifestation of late stent thrombosis after DES implantation. The incomplete regeneration of the endothelial layer poststenting triggers adverse signaling processes precipitating in thrombosis. Various approaches have been attempted to prevent thrombosis, including the delivery of biological agents, such as estradiol, that promote endothelialization, and the use of natural polymers as coating materials. The underlying challenge has been the inability to release the biological agent in synchronization with the temporal sequence of vascular wound healing in vivo. The natural healing process of the endothelium after an injury starts after a week and may take up to a month in humans. This article presents a novel DES formulation using a hemocompatible polyurethane (PU) matrix to sustain the release of probucol (PB), an endothelial agonist, by exploiting the greater difference in the solubility parameters of PB and PU. This results in the formation of crystalline PB aggregates retarding drug release from PU. The physicochemical properties of PB in PU were confirmed using differential scanning calorimetry and X‐ray diffraction. Drug‐polymer compatibility was examined using infrared spectral analysis. Also, in vitro studies using primary human aortic endothelial cells resulted in the selection of 5% w/w PB as the optimal dose, to be further tested in vitro and in vivo. This work develops and tests a promising new DES formulation to enable faster endothelial cell proliferation poststenting, potentially minimizing the incidence and severity of thrombotic events after DES implantation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.