bluuebunny/crossref_metadata_2025_split huggingface dataset:
Additional value of gadoxetic acid‐DTPA‐enhanced hepatobiliary phase MR imaging in the diagnosis of early‐stage hepatocellular carcinoma: Comparison with dynamic triple‐phase multidetector CT imaging
Authors: Haradome Hiroki , Grazioli Luigi , Tinti Rita , Morone Mario , Motosugi Utaroh , Sano Katsuhiro , Ichikawa Tomoaki , Kwee Thomas C. , Colagrande Stefano 
Published: May 2011

AbstractPurpose:To assess the value of hepatobiliary phase gadoxetic acid (EOB)‐enhanced magnetic resonance imaging (MRI) for the diagnosis of early stage hepatocellular carcinoma (HCC) (<3 cm) compared to triple‐phase dynamic multidetector computed tomography (MDCT).Materials and Methods:In all, 52 patients with 60 pathologically proven HCCs underwent both EOB‐enhanced MRI and triple‐phase dynamic MDCT. Two radiologists independently and blindly reviewed three image sets: 1) MDCT, 2) dynamic MRI (unenhanced and EOB‐enhanced dynamic MR images), and 3) combined MRI (dynamic MRI + hepatobiliary phase images) using a five‐point rating scale on a lesion‐by‐lesion basis. Receiver operating characteristics (ROC) analysis was performed, and sensitivity and specificity were calculated.Results:The area under the ROC curve (Az) of dynamic MRI was equivalent to that of MDCT for both readers. For both readers, Az and sensitivity of combined MRI for smaller lesions (<1.5 cm) were significantly higher than that of dynamic MRI and MDCT (P < 0.0166). The majority of false‐negative nodules on dynamic MRI or MDCT (75% and 62%, respectively) were due to a lack of identified washout findings.Conclusion:Hepatobiliary phase images can increase the value of EOB‐enhanced MRI in the diagnosis of early stage HCC. The sensitivity and accuracy were significantly superior to MDCT for the diagnosis of lesions less than 1.5 cm. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Simultaneous bilateral magnetic resonance imaging of the femoral arteries in peripheral arterial disease patients
Authors: Brown Ryan , Karmonik Christof , Brunner Gerd , Lumsden Alan , Ballantyne Christie , Johnson Shawna , Wang Yi , Morrisett Joel 
Published: May 2011

AbstractPurpose:To image the femoral arteries in peripheral arterial disease (PAD) patients using a bilateral receive coil.Materials and Methods:An eight‐channel surface coil array for bilateral MRI of the femoral arteries at 3T was constructed and evaluated.Results:The bilateral array enabled imaging of a 25‐cm segment of the superficial femoral arteries (SFA) from the profunda to the popliteal. The array provided improved the signal‐to‐noise ratio (SNR) at the periphery and similar SNR in the middle of a phantom compared to three other commercially available coils (4‐channel torso, quadrature head, whole body). Multicontrast bilateral images of the in vivo SFA with 1 mm in‐plane resolution made it possible to directly compare lesions in the index SFA to the corresponding anatomical site in the contralateral vessel without repositioning the patient or coil. A set of bilateral time‐of‐flight, T1‐weighted, T2‐weighted, and proton density‐weighted images was acquired in a clinically acceptable exam time of ≈45 minutes.Conclusion:The developed bilateral coil is well suited for monitoring dimensional changes in atherosclerotic lesions of the SFA. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Distinguishing hemangiomas from malignant solid hepatic lesions: A comparison of heavily T2‐weighted images obtained before and after administration of gadoxetic acid
Authors: Ahn Sung Jun , Kim Myeong‐Jin , Hong Hye‐Suk , Ah Kim Kyung , Song Ho‐Taek 
Published: May 2011

AbstractPurpose:To compare the use of heavily T2‐weighted images obtained before and after administration of gadoxetic acid in differentiating hemangiomas from malignant solid hepatic lesions.Materials and Methods:Heavily T2‐weighted images (TE = 150 msec) were obtained for 70 patients (42 men and 28 women) with 74 focal hepatic lesions (25 hepatocellular carcinomas [HCC], 22 metastases, and 27 hemangiomas) ≤3 cm in diameter before and after gadoxetic acid‐enhanced dynamic magnetic resonance imaging (MRI). Quantitative analysis was performed using receiver operating characteristic (ROC) curves with lesion‐to‐liver signal intensity difference‐to‐noise ratio (SDNR) on precontrast and postcontrast images. Qualitative analysis was also performed by two blinded reviewers.Results:The SDNR of the solid lesions was significantly higher on the postcontrast (1.66 ± 1.18) than on the precontrast (1.38 ± 1.07) images (P = 0.0012), while the SDNR of hemangiomas was comparable for pre‐ and postcontrast images (P = 0.8164). The best SDNR cutoff values for distinguishing solid lesions from hemangiomas were ≤1.85 (Az = 0.948) for precontrast and ≤2.58 (Az = 0.901) for postcontrast images (P = 0.057). Reader performances for distinguishing hemangiomas from solid lesions were comparable between the precontrast (Az = 0.975 and 0.970 for readers 1 and 2) and postcontrast (Az = 0.977 and 0.972) images (P = 0.899 and 0.946).Conclusion:Heavily T2‐weighted images obtained after administration of gadoxetic acid have a diagnostic capability comparable to precontrast images for differentiating between small hemangiomas and malignant solid lesions of the liver. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Sex‐ and brain region‐specific role of cytochrome c oxidase in 1‐methyl‐4‐phenylpyridinium‐mediated astrocyte vulnerability
Authors: Sundar Boyalla Syama , Barbara Victor Marion , Roemgens André , Beyer Cordian , Arnold Susanne 
Published: May 2011

AbstractParkinson's disease is a neurodegenerative disorder characterized by a sex and brain region specificity, showing a higher incidence in men than in women, which is caused by cell death of mainly dopaminergic neurons in the mesencephalon. Mitochondrial toxins are often used to trigger and mimic neurodegenerative processes. Thus, systemic application of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) induces Parkinsonian symptoms, indicating a causative or consequent involvement of mitochondria. Therefore, mitochondria of neural cells may demonstrate a sex and brain region specificity with respect to structural and functional characteristics of these organelles during toxic and degenerative processes. The application of MPTP in vivo and its toxic derivative 1‐methyl‐4‐phenylpyridinium (MPP+) in vitro represent a well‐accepted experimental model of Parkinson's disease. Aside from the known effects of MPP+ on mitochondria and neural cell survivability and with respect to the supportive role of astrocytes for neuronal function, we aimed to demonstrate the involvement of cytochrome c oxidase subunit IV isoform expression in energy and reactive oxygen species production taking part in an impairment of astrocyte survival. MPP+ caused a specific increase of COX IV‐2 transcript and protein levels in male mesencephalic astrocytes, accompanied by decreased ATP and increased reactive oxygen species levels and elevated apoptotic cell death, which were more pronounced in mesencephalic than in cortical astrocytes from male than from female mice. Our data suggest that MPP+ acts on astrocytes in a sex‐ and brain region‐specific manner involving cytochrome c oxidase isoform expression in an impairment of energy production and elevated oxidative stress levels, which represent hallmarks of neurodegenerative diseases. © 2011 Wiley‐Liss, Inc.
Thriving at work: Toward its measurement, construct validation, and theoretical refinement
Authors: Porath Christine , Spreitzer Gretchen , Gibson Cristina , Garnett Flannery G. 
Published: May 2011

SummaryThriving is defined as the psychological state in which individuals experience both a sense of vitality and learning. We developed and validated a measure of the construct of thriving at work. Additionally, we theoretically refined the construct by linking it to key outcomes, such as job performance, and by examining its contextual embeddedness. In Study 1, we conducted second‐order confirmatory factor analyses in two samples, demonstrating initial support for the two‐dimensional structure of thriving. We provided evidence for the convergent and discriminant validity of thriving in relation to theoretically related constructs, such as positive and negative affects, learning and performance goal orientations, proactive personality, and core self‐evaluations. In Study 2, across two different samples, we further assessed construct validity by establishing a relationship between thriving and career development initiative, burnout, health, and individual job performance, explaining significant variance beyond traditional attitudinal predictors, such as job satisfaction and organizational commitment. Finally, in Study 3, we focused on understanding the contextual embeddedness of thriving. We found differences in reports of thriving across two points in time, when substantial changes are occurring in peoples' work lives and across contexts (i.e., work and non‐work). Implications for theory and practice, as well as directions for future research, are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
On two different objective procedures for classifying synoptic weather types over east Australia
Authors: Jiang Ningbo , Cheung Kevin , Luo Kehui , Beggs Paul J. , Zhou Wen 
Published: May 2011

AbstractSynoptic weather typing depends on the method and its implementation. This paper demonstrates the utility of a 2‐phase batch self‐organising map procedure (CP2) in comparison with a procedure (CP1) consisting of T‐mode principal component analysis followed by convergent K‐means clustering, for classifying the synoptic weather types over east Australia. Four classifications were obtained for the 52‐year NCEP/NCAR dataset, one from CP1 and three from CP2. These classifications were examined in terms of grouping quality, mean type maps, type frequencies, lifetime and transitions, and in relation to the Southern Oscillation Index (SOI).The results showed that the classifications derived from different procedures are inter‐confirmative and capture a similar set of major synoptic situations influencing east Australia, each having counterparts in previous studies and conforming well to local synoptic experience. In particular, this study demonstrates that CP2 is a promising tool for the purpose of weather typing with a two‐fold utility: CP2 can perform data projection (neighbourhood width > = 1) and provide a flexible means for visualising the broad distribution of the daily weather patterns in the dataset; and the procedure can also conduct cluster analysis (neighbourhood width = 0) and produce results equivalent to those from CP1. It was found that performing data clustering or data projection may affect the inference associated with type frequencies. While focusing on methodology, the analysis has also shown that the frequency of synoptic weather types fluctuates on the seasonal, interannual, and decadal scales. From the 1970s to 1995 there was a decline in the occurrence of a few weather types associated with an east‐coast trough extending over New South Wales from the north, and a slight increase in the activity of some anticyclonic types. Significant correlations were also identified between SOI and frequencies of synoptic weather types on the annual and seasonal timescales. Copyright © 2011 Royal Meteorological Society
Differential gene expression and immunolocalization of insulin‐like growth factors and insulin‐like growth factor binding proteins between experimental nonunions and standard healing fractures
Authors: Koh Akihiro , Niikura Takahiro , Lee Sang Yang , Oe Keisuke , Koga Takaaki , Dogaki Yoshihiro , Kurosaka Masahiro 
Published: May 2011

AbstractInsulin‐like growth factors (IGF‐I/II) are important growth factors in bone, and their actions are regulated by six IGF binding proteins (IGFBPs). However, little is known about their exact functions in fracture healing. The aim of this study was to compare the gene expression and immunolocalization of IGFs and IGFBPs between standard healing fractures and nonunions using rat experimental models. Standard healing fractures and nonunions produced by periosteal cauterization at the fracture site were created in rat femurs. At postfracture days 3, 7, 10, 14, 21, and 28, total RNA was extracted from the callus of the healing fractures and the fibrous tissue of the nonunions, and gene expression were analyzed by real‐time PCR. Additionally, immunolocalization of these proteins was studied by immunohistochemistry at postfracture days 7, 14, and 21. In nonunions, the gene expression of IGF‐I/II and IGFBP‐6 was significantly higher, and that of IGFBP‐5 was significantly lower at several time points. The immunolocalization of IGF‐I/II and IGFBP‐5 was widely distributed in both models. In contrast, that of IGFBP‐6 was barely detected in the fracture callus. In conclusion, our results suggest that IGFs/IGFBPs may have important roles not only in fracture healing but also in nonunion formation. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1820–1826, 2011
Oxygen vacancy‐induced microstructural changes of annealed CeO2−xnanocrystals
Authors: Aškrabić S. , Dohčević‐Mitrović Z. , Kremenović A. , Lazarević N. , Kahlenberg V. , Popović Z. V. 
Published: May 2011

AbstractNanocrystalline ceria (CeO2) is known for its ionic conductivity and oxygen storage properties, which depend on the presence of oxygen ion vacancies. The vacancies cause several important changes in CeO2involving microstrain, electronic structure, magnetic properties, etc. In this article, we focus our attention to the microstructural changes of nanocrystalline CeO2−xannealed at different temperatures in the range 200–500 °C. Structural and vibrational properties were investigated by X‐ray diffraction and Raman spectroscopy. It was observed that the content of oxygen vacancies changed significantly with increasing annealing temperature, which plays an important role in the observed microstructural changes of the annealed samples. We demonstrate that the observed microstrain changes, because of variable defect content, dominate over the crystallite size effect. This finding is opposite to the conclusions made by several other authors. A new mode, classified as a probable surface mode, was observed in the Raman spectra at ∼480 cm−1, the appearance of which can be explained by the large defective structure and disorder in the ceria lattice. Copyright © 2011 John Wiley & Sons, Ltd.
Shell‐isolated nanoparticle enhanced Raman spectroscopy (SHINERS) investigation of benzotriazole film formation on Cu(100), Cu(111), and Cu(poly)
Authors: Honesty Nicole R. , Gewirth Andrew A. 
Published: May 2011

AbstractBenzotriazole (BTAH) is well known as an effective corrosion inhibitor for Cu because of its ability to make a coordination polymer film on the surface that provides a barrier to Cu oxidation. BTA− film formation was investigated on single‐crystal and polycrystalline Cu surfaces with shell‐isolated nanoparticle enhanced Raman spectroscopy (SHINERS) using silica‐encapsulated Au nanoparticles. Potential‐dependent spectra display reversible film formation on polycrystalline Cu and irreversible film formation on single‐crystal Cu. Grain boundaries leading to smaller BTA−‐Cu oligomers are proposed to be the reason for cathodic degradation of the BTA− polymeric films on polycrystalline Cu. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of ionic liquid‐bonded organic‐silica hybrid monolithic column for capillary electrochromatography
Authors: Han Haifeng , Li Jing , Wang Xusheng , Liu Xia , Jiang Shengxiang 
Published: May 2011

AbstractAn ionic liquid (IL) was introduced into the organic‐silica hybrid monolithic column as the stationary phase for capillary electrochromatography (CEC). The monolithic silica matrix containing chloropropyl functional group was prepared by the in situ co‐condensation of tetramethoxysilane and (3‐chloropropyl)‐trimethoxysilane via a sol–gel process and chemical modification with N‐methylimidazole. The electroosmotic flow of the IL‐modified hybrid monolithic column was reversed at acidic pH and the morphology of the column was characterized by scanning electron microscope. Four aromatic hydrocarbons were completely separated with 40% acetonitrile phosphate buffer as the mobile phase and seven inorganic ions were efficiently separated with the phosphate buffer on the column in CEC. Reproducibilities of migration time for four aromatic hydrocarbons (benzene, naphthalene, anthracene, chrysene) were acceptable on IL‐modified hybrid monolithic columns. Relative standard deviations of run‐to‐run (n=5), peak area‐to‐peak area (n=5), day‐to‐day (n=3) and column‐to‐column (n=3) were in the range of 0.72–0.88, 1.47–5.40, 2.44–4.99 and 3.01–8.11%, respectively.
QuEChERS‐based extraction procedure for multifamily analysis of phytohormones in vegetables by UHPLC‐MS/MS
Authors: Flores María Isabel Alarcón , Romero‐González Roberto , Frenich Antonia Garrido , Vidal José Luis Martínez 
Published: May 2011

AbstractA new method has been developed and validated for the simultaneous analysis of different phytohormones (auxins, cytokinins and gibberellins) in vegetables. The compounds were extracted using a QuEChERS‐based method (acronym of quick, easy, cheap, effective, rugged and safe). The separation and determination of the selected phytohormones were carried out by ultra high‐performance liquid chromatography coupled to tandem mass spectrometry (UHPLC‐MS/MS), using electrospray ionization source (ESI) in positive and negative ion modes. The method was validated and mean recoveries were evaluated at three concentration levels (50, 100 and 250 μg/kg), ranging from 75 to 110% at the three levels assayed. Intra‐ and interday precisions, expressed as relative standard deviations (RSDs), were lower than 20 and 25%, respectively. Limits of quantification (LOQs) were equal or lower than 10 μg/kg. The developed procedure was applied to seven courgette samples, and naphthylacetic acid, naphthylacetamide and benzyladenine were found in some of the analysed samples.
Effects of functional monomers on retention behavior of small and large molecules in monolithic capillary columns at isocratic and gradient conditions
Authors: Urban Jiří , Jandera Pavel , Langmaier Pavel 
Published: May 2011

AbstractThe polarity of (poly)methacrylate monolithic capillary columns was varied by using alkylmethacrylate monomers with butyl, cyclohexyl, 2‐ethylhexyl, lauryl, and stearyl functional groups in the polymerization mixture. The hydrodynamic properties, as well as the retention characteristics in RP‐LC of small molecules (alkylbenzenes) and of proteins under gradient elution conditions were studied. The RP selectivity depends on the type of alkyl chain in methacrylate monomer; however, there was no direct correlation between the size of the monomer molecule and methylene or aromatic selectivity of the monlithic column. The lowest selectivity was found for column based on lauryl methacrylate monomer. On the other hand, butyl methacrylate column shows high phenyl selectivity and the column with stearyl methacrylate possesses the highest methylene selectivity for small molecules. The retention increases with longer alkyl chain in methacrylate monomer, especially for high molar mass proteins on all prepared columns and showed gradient elution behavior of proteins in agreement with the linear solvent strength gradient model. The poly(laurylmethacrylate) column showed lowest hydrophobicity but best efficiency for proteins of all columns tested.
A Nanocage for Nanomedicine: Polyhedral Oligomeric Silsesquioxane (POSS)
Authors: Ghanbari Hossein , Cousins Brian G. , Seifalian Alexander M. 
Published: May 2011

AbstractGround‐breaking advances in nanomedicine (defined as the application of nanotechnology in medicine) have proposed novel therapeutics and diagnostics, which can potentially revolutionize current medical practice. Polyhedral oligomeric silsesquioxane (POSS) with a distinctive nanocage structure consisting of an inner inorganic framework of silicon and oxygen atoms, and an outer shell of organic functional groups is one of the most promising nanomaterials for medical applications. Enhanced biocompatibility and physicochemical (material bulk and surface) properties have resulted in the development of a wide range of nanocomposite POSS copolymers for biomedical applications, such as the development of biomedical devices, tissue engineering scaffolds, drug delivery systems, dental applications, and biological sensors. The application of POSS nanocomposites in combination with other nanostructures has also been investigated including silver nanoparticles and quantum dot nanocrystals. Chemical functionalization confers antimicrobial efficacy to POSS, and the use of polymer nanocomposites provides a biocompatible surface coating for quantum dot nanocrystals to enhance the efficacy of the materials for different biomedical and biotechnological applications. Interestingly, a family of POSS‐containing nanocomposite materials can be engineered either as completely non‐biodegradable materials or as biodegradable materials with tuneable degradation rates required for tissue engineering applications. These highly versatile POSS derivatives have created new horizons for the field of biomaterials research and beyond. Currently, the application of POSS‐containing polymers in various fields of nanomedicine is under intensive investigation with expectedly encouraging outcomes. magnified image
Crystalline Complex of Syndiotactic Polystyrene with Poly(ethylene Glycol) Dimethyl Ethers
Authors: Kaneko Fumitoshi , Sasaki Keita 
Published: May 2011

AbstractIt has been clarified that syndiotactic polystyrene (sPS) forms co‐crystalline structures with polyethylene glycol dimethyl ethers (PEGDMEs) with molecular weights ranging from 178 to 1 000 g · mol−1 through a guest exchange procedure assisted by a plasticizing agent. The PEGDME molecules are incorporated into the spaces between sPS polymer sheets consisting of (T2G2)2 helices. The results of X‐ray diffraction and gravimetric measurements suggest that one or less molecules are included per unit cell for PEGDME with average molecular weight of 1 000 g · mol−1, which indicates the possibility that longer polymeric molecules can be introduced into sPS lattices with multiple site occupation. magnified image
Output error estimation strategies for discontinuous Galerkin discretizations of unsteady convection‐dominated flows
Authors: Fidkowski Krzysztof J. 
Published: May 2011

AbstractWe study practical strategies for estimating numerical errors in scalar outputs calculated from unsteady simulations of convection‐dominated flows, including those governed by the compressible Navier–Stokes equations. The discretization is a discontinuous Galerkin finite element method in space and time on static spatial meshes. Time‐integral quantities are considered for scalar outputs and these are shown to superconverge with temporal refinement. Output error estimates are calculated using the adjoint‐weighted residual method, where the unsteady adjoint solution is obtained using a discrete approach with an iterative solver. We investigate the accuracy versus computational cost trade‐off for various approximations of the fine‐space adjoint and find that exact adjoint solutions are accurate but expensive. To reduce the cost, we propose a local temporal reconstruction that takes advantage of superconvergence properties at Radau points, and a spatial reconstruction based on nearest‐neighbor elements. This inexact adjoint yields output error estimates at a computational cost of less than 2.5 times that of the forward problem for the cases tested. The calculated error estimates account for numerical error arising from both the spatial and temporal discretizations, and we present a method for identifying the percentage contributions of each discretization to the output error. Copyright © 2011 John Wiley & Sons, Ltd.