bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D contrast‐enhanced MR angiography
Authors: Zhang HongLei , Maki Jeffrey H. , Prince Martin R. 
Published: December 2006

AbstractSafe, fast, accurate contrast arteriography can be obtained utilizing gadolinium (Gd) and 3D MR data acquisition for diagnosing vascular diseases. Optimizing contrast enhanced MRA (CE MRA), however, requires understanding the complex interplay between Gd injection timing, the Fourier mapping of 3D MR data acquisition and a multitude of parameters determining resolution, anatomic coverage, and sensitivity to motion artifacts. It is critical to time the bolus peak to coincide with central k‐space data acquisition, which dominates image contrast. Oversampling the center of k‐space allows reconstruction of multiple 3D acquisitions in rapid succession to time‐resolve the passage of the contrast bolus. Parallel imaging increases resolution, shortens scan time and compresses the center of k‐space into a shorter period of time, thereby minimizing motion and timing artifacts. Absence of ionizing radiation allows MRA to be repeated and combined with additional sequences to more fully characterize anatomy, flow, and physiology. Utilizing stepping table technology and thigh compression, whole body MRA is possible with a single contrast injection. As MR technology continues to advance, CE MRA becomes better and simpler to perform, increasing its efficacy in the diagnosis and management of vascular diseases. J. Magn. Reson. Imaging 2007. © 2006 Wiley‐Liss, Inc.
Assessment of diffusion‐weighted MR imaging in liver fibrosis
Authors: Annet Laurence , Peeters Frank , Abarca‐Quinones Jorge , Leclercq Isabelle , Moulin Pierre , Van Beers Bernard E. 
Published: December 2006

AbstractPurposeTo assess whether hepatic fibrosis is associated with a restriction in the diffusion of water that can be analyzed with diffusion‐weighted MR imaging (DWI) of the liver.Materials and MethodsDWI was performed in 10 normal rats and 15 rats with liver fibrosis. Echo‐planar DWI was performed in the living rats at 1.5 T and repeated immediately after the animals were killed. Afterwards the livers were explanted, fixed in Bouin solution, and imaged with a DW spin‐echo sequence at 4.7 T. Fibrosis was quantified by densitometry on Sirius red‐stained histological sections.ResultsIn living rats the apparent diffusion coefficient (ADC) decreased with the severity of liver fibrosis (controls: 1535 ± 294 mm2/second; CCl4 (5 weeks) 1129 ± 273 mm2/second; CCl4 (9 weeks): 943 ± 132 mm2/second; P = 0.002). An inverse correlation between ADC and liver fibrosis volume density was observed (r = –0.712, P < 0.001). In contrast, these findings were not observed in the rats after they were killed or in the fixated livers.ConclusionDecreased ADC correlated with increased liver fibrosis in living rats, but not after death. These results suggest that restricted water diffusion cannot be assessed by DWI in liver fibrosis. Other factors, such as a decrease of perfusion, may explain the decrease of the hepatic ADC measured in vivo in rats with liver fibrosis. J. Magn. Reson. Imaging 2007. © 2006 Wiley‐Liss, Inc.
Pulmonary MR perfusion at 3.0 Tesla using a blood pool contrast agent: Initial results in a swine model
Authors: Nael Kambiz , Saleh Roya , Nyborg Glen K. , Fonseca Carissa G. , Weinmann Hanns Joachim , Laub Gerhard , Finn J. Paul 
Published: December 2006

AbstractPurposeTo prospectively evaluate the technical feasibility of a highly accelerated pulmonary MR perfusion protocol at 3.0T using a blood pool contrast agent in a swine model.Materials and MethodsTwelve pigs underwent time‐resolved pulmonary MR angiography (MRA) on a 3.0T MR system under anesthesia and controlled mechanical ventilation. After intravenous injection of 0.05 mmol/kg of Gadomer‐17 at 4 mL/second, a fast time‐resolved MRA sequence with temporal echo‐sharing (three segmented k‐space) and highly accelerated parallel acquisition was used to acquire 3D data sets with an in‐plane resolution of 1 × 1 mm2 (slice thickness = 6 mm) and temporal resolution of one second. Image quality was evaluated independently by two radiologists, and quantitative analysis of perfusion parameters was performed using pre‐released perfusion software.ResultsAll studies were identified by both readers as having diagnostic image quality (range = 2–3, median = 3) and there was excellent interobserver agreement (κ = 0.89; 95% CI = 0.83, 0.95). A quantitative analysis of perfusion indices was performed, with excellent overall goodness‐of‐fit (χ2 value = 1.4, degree of freedom (DF) = 1). Successfully derived perfusion parameters included the time to peak (TTP, 5.1 ± 0.7 second), mean transit time (MTT, 6.6 ± 0.9 second), maximal signal intensity (MSI, 1051.2 ± 718.9 arbitrary units [A.U.]), and maximal upslope of the curve (MUS, 375.9 ± 263.4 A.U./second).Conclusion3.0T pulmonary MR perfusion using a blood pool contrast agent in a swine model is feasible. The higher available signal‐to‐noise ratio (SNR) at 3.0T and the high T1 relaxivity of Gadomer‐17 effectively support highly accelerated parallel acquisition, and improve the performance of time‐resolved pulmonary MRA. J. Magn. Reson. Imaging 2007. © 2006 Wiley‐Liss, Inc.
Perceived organizational support and affective commitment: the mediating role of organization‐based self‐esteem in the context of job insecurity
Authors: Lee Jaewon , Peccei Riccardo 
Published: December 2006

AbstractResearch on the relationship between perceived organizational support (POS) and affective organizational commitment (AC) has primarily adopted a social exchange perspective. In this study we considered complementary socio‐emotional explanations of the POS–AC relationship. We focused on the mediating role of organization‐based self‐esteem (OBSE) and tested competing models of the POS–OBSE‐AC relationship separately on data from two Korean banks that experienced different levels of downsizing following the 1997 Korean financial crisis. We further extended the analysis by examining the extent to which the relationship between POS and OBSE and AC, respectively, was affected by employees' perceived sense of job insecurity in the two banks. The results showed that OBSE was a significant mediator of the POS–AC relationship in both organizations. POS, however, also retained a strong independent direct effect on commitment. Moreover, as expected, perceived job insecurity tended to attenuate the POS–OBSE relationship, but augmented the direct relationship between perceived organizational support and affective commitment. Copyright © 2006 John Wiley & Sons, Ltd.
Voltammetric methods for the simultaneous determination of trace metals in foods, plant tissues and soils
Authors: Locatelli Clinio 
Published: December 2006

AbstractAn analytical procedure for the sequential determination of copper(II), chromium(VI), thallium(I), lead(II), tin(II), antimony(III) and zinc(II) by anodic stripping voltammetry (ASV) in three interdependent matrices involved in foods and food chain as meals, cereal plants and soils is described. The digestion of each matrix was carried out using a mixture of concentrated acids: HClHNO3H2SO4 for meals and cereal plants, and HClHNO3 for soils. Dibasic ammonium citrate (0.1 mol L−1; at either pH 6.2 or 8.3) was used as the supporting electrolyte. The voltammetric measurements were carried out using, as working electrode, a stationary hanging mercury drop electrode (HMDE) and a platinum electrode and an Ag|AgCl|KClsat. electrode as auxiliary and reference electrodes, respectively. The analytical procedure was verified by the analyses of the standard reference materials: Wholemeal BCR‐CRM 189, Wheat Flour NIST‐SRM 1567a, Tomato Leaves NIST‐SRM 1573a and Montana Soil Moderately Elevated Traces NIST‐SRM 2711. For all the elements in the certified matrix, the precision as repeatability, expressed as relative standard deviation (sr) was of the order of 3–5%. The accuracy, expressed as relative error (e) was of the order of 3–7%, while the detection limits were in the range 0.011–0103 µg g−1. Once set up on the standard reference materials, the analytical procedure was transferred and applied to commercial meal samples and cereal plants and soil samples taken from sites used for agriculture. A critical comparison with spectroscopic measurements is also discussed. Copyright © 2006 Society of Chemical Industry
Anti‐wear performance of organomolybdenum compounds as lubricant additives
Authors: Feng Xie , Jianqiang Hu , Fazheng Zheng , Feng Ji , Junbing Yao 
Published: December 2006

AbstractA four‐ball tester was used to evaluate the anti‐wear performance of three kinds of organomolybdemun compounds in engine oils and lithium soap grease, i.e. molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate (MoDTC), and sulphur‐ and phosphorus‐free organomolybdeum (molybdate). The results indicate that a low concentration of MoDDP does not improve the anti‐wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti‐wear properties of the engine oils. MoDTC does not improve the anti‐wear properties of the engine oils, but worsens the anti‐wear properties of the oils. Significant improvement of the anti‐wear properties is obtained with molybdate added in the four fully formulated oils. Both MoDDP and molybdate have good anti‐wear properties in the lithium soap grease, especially MoDDP with a high concentration. Copyright © 2006 John Wiley & Sons, Ltd.
Mass spectrometry for the quantification of bioactive peptides in biological fluids
Authors: Tamvakopoulos Constantin 
Published: December 2006

AbstractThe study of pharmacologically active peptides is central to the understanding of disease and development of novel therapies. It would be advantageous to monitor the fate of bioactive peptides in biological fluids and tissues following theirin vivoadministration (exogenous administration) or the modulation of endogenous factors (e.g., peptide hormones) affected by the administration of a pharmacological agent. Measurement of administered compounds (small molecules) in plasma is a mature field. However, measurement of pharmacologically active peptides presents particular problems for quantitative mass spectrometry, including challenges from selectivity and sensitivity perspectives. Current approaches towards peptide quantification in biological fluids include immunoassays and mass spectrometric techniques. Immunoassays, although sensitive, lack the necessary selectivity for distinction between peptide and metabolites. Modified molecules induced by metabolic transformations (e.g.,N‐ orC‐terminal truncation of the peptide) might not be differentiated by the antibody used in the assay, leading to cross‐reactivity. However, although it is generally accepted that mass spectrometry is an ideal technique for the quantification of trace levels of analytes in biological fluids, immunological techniques are still characterized by better limits of peptide detection. In this review article, novel mass spectrometric approaches and strategies on peptide quantification will be described. The current capabilities and prospects for advances in this critical area of research will be examined. © 2006 Wiley Periodicals, Inc., Mass Spec Rev
Procedure for reliable durability validation of train axles
Authors: Grubisic V. , Fischer G. 
Published: December 2006

AbstractThe structural durability of wheelset axles depends on the operational loading as well as on the fatigue strength of axles. To validate an axle design the time‐varying stresses in individual critical areas of the axle, represented by their stress spectra, must be taken into account. The allowable stresses in individual axle areas depend both on the fatigue strength and on the spectrum of operational stresses. The procedure for the axle structural durability validation, presented in this paper, includes the numerical fatigue life estimation as well as the experimental durability approval. Also the influences of axle design, material properties and manufacturing technology on structural durability are discussed.
Invarianten‐basierte Mehrachsigkeitshypothese zur Anwendung bei Schwingbeanspruchung
Authors: Amstutz H. , Vormwald M. , Olivier R. 
Published: December 2006

AbstractDie Abschätzung der Lebensdauer bei mehrachsiger Schwingbeanspruchung durch Bezug auf die Wöhlerlinie für reine Zug‐/Druckbeanspruchung führt mit zunehmendem Einfluss einer Schubspannungskomponente häufig zu größeren Abweichungen vom Versuch. Eine deutliche Verbesserung der Vorhersage ist demnach durch Anbindung sowohl an die Wöhlerlinien aus reiner Zug‐/Druckbeanspruchung als auch der aus reiner Schubbeanspruchung zu erwarten.Auf der Grundlage einer invarianten‐basierten Vergleichsspannung wird in diesem Beitrag eine Hypothese entwickelt, bei der die beiden Grenzfälle exakt erfüllt sind und die für allgemein mehrachsige Beanspruchung zwischen den Grenzfällen interpoliert. Eine empirisch abgestützte Modifikation der Hypothese schließt nichtproportionale Verläufe aus Phasenverschiebung zwischen den Komponenten ein.
Simulation von Schädigungs‐ und Kriechvorgängen im Asphalt
Authors: Herz E. , Vormwald M. 
Published: December 2006

AbstractIn wachsendem Maße besteht Bedarf, nummerische Methoden zur Bemessung von Straßen einzusetzen. Dabei liegt die Hauptschwierigkeit in der Abbildung des hochkomplexen, nichtlinearen Materialverhaltens von Asphalt. In der vorliegenden Arbeit wird ein kontinuumsmechanisches Materialmodell vorgestellt, das dazu dient, die wesentlichen nichtlinearen mechanischen Prozesse, die in Asphalt ablaufen, zu modellieren. Dazu zählen plastische Verformungen, Schädigung und Rissbildung sowie viskose Prozesse.Das Modell wird im Rahmen von FEM‐Berechnungen mit dem Programmpaket Abaqus zur Simulation von Asphaltversuchen angewendet.
Quantification of intramyocellular lipids in obese subjects using spectroscopic imaging with high spatial resolution
Authors: Weis J. , Johansson L. , Courivaud F. , Karlsson F.A. , Ahlström H. 
Published: December 2006

AbstractQuantification of intramyocellular lipids (IMCL) in obese subjects by single‐voxel spectroscopy (SVS) or conventional spectroscopic imaging (SI) often fails due to overlap of IMCL spectral lines by extramyocellular lipids (EMCL), and signal contamination from subcutaneous fat and bone marrow. This study demonstrates that these problems can be solved by high‐resolution SI with 128 phase‐encoding steps and a read gradient during acquisition. The small voxels obtained in this way facilitated differentiation between EMCL and IMCL. This method offers the possibility of studying different muscle groups and the variation of lipids within one muscle. Magn Reson Med 57:22–28, 2007. © 2006 Wiley‐Liss, Inc.
Real‐time gating system for mouse cardiovascular MR imaging
Authors: Sabbah Maher , Alsaid Hasan , Fakri‐Bouchet Latifa , Pasquier Cédric , Briguet André , Canet‐Soulas Emmanuelle , Fokapu Odette 
Published: December 2006

AbstractMouse cardiac MR gating using ECG is affected by the hostile MR environment. It requires appropriate signal processing and correct QRS detection, but gating software methods are currently limited. In this study we sought to demonstrate the feasibility of digital real‐time automatically updated gating methods, based on optimizing a signal‐processing technique for different mouse strains. High‐resolution MR images of mouse hearts and aortic arches were acquired using a chain consisting of ECG signal detection, digital signal processing, and gating signal generation modeled using Simulink (The MathWorks, Inc., Natick, MA, USA). The signal‐processing algorithms used were respectively low‐pass filtering, nonlinear passband, and wavelet decomposition. Both updated and nonupdated gating signal generation methods were tested. Noise reduction was assessed by comparison of the ECG signal‐to‐noise ratio (SNR) before and after each processing step. Gating performance was assessed by measuring QRS detection accuracy before and after online trigger‐level adjustments. Low‐pass filtering with trigger‐level adjustment gave the best performance for mouse cardiovascular imaging using gradient‐echo (GE), spin‐echo (SE), and fast SE (FSE) sequences with minimum induced delay and maximum gating efficiency (99% sensitivity and R‐peak detection). This simple digital gating interface will allow various gating strategies to be optimized for cardiovascular MR explorations in mice. Magn Reson Med 57:29–39, 2007. © 2006 Wiley‐Liss, Inc.
Systematic literature review of treatment interventions for upper extremity hemiparesis following stroke
Authors: Urton Marjorie L. , Kohia Mohamed , Davis Janis , Neill Megan R. 
Published: December 2006

AbstractThe primary purpose of this review article is to critically analyse the literature from 1999 to 2005 regarding effective interventions for upper extremity hemiparesis following stroke. The researchers narrowed the scope of the review based on inclusion and exclusion criteria, which yielded 11 pertinent studies congruent with the selection criteria. Studies were categorized using Sackett's levels of evidence, level I being the highest degree of certainty and level V the lowest. Grades of recommendations were then developed, grade A being highly recommended, grade B discretionary and grade C not endorsed. Two studies were endorsed as level I – grade A, six were level II – grade B, and three were level III – grade C. Clinical recommendations inferred from the present evaluation are as follows:• Electrical stimulation can be used to improve upper limb outcomes in patients with moderate to severe upper limb dysfunction and is feasible for home‐based interventions.• Therapy that utilizes goal‐directed reaching behaviours promotes more typical reaching patterns than non‐goal‐directed interventions.• Reach‐to‐grasp movements show greater improvement when compensatory trunk movements are reduced.• As an addition to regular exercise therapy time, Arm BASIS training may enhance selective movements of the upper extremity (i.e. reaching).• When performed in conjunction with active neuromuscular stimulation, random and blocked practice may improve pre‐motor, motor and total reaction times of the upper extremity. Copyright © 2006 John Wiley & Sons Ltd.
Evaluation of Daphne genkwa diterpenes: Fingerprint and quantitative analysis by high performance liquid chromatography
Authors: Zhang Shixuan , Zhang Fenghong , Li Xiaona , Dong Weiqun , Wen Luohan , Wang Shisheng 
Published: December 2006

AbstractDaphne genkwa contains a novel class of anticancer diterpene esters that inhibit DNA topoisomerase I. Fingerprint and quantitative analysis by HPLC were performed in order to characterise and evaluate D. genkwa. A standard fingerprint of Daphne diterpene esters from the root extract was first established by HPLC‐UV, and the major peaks in the fingerprint profile were preliminarily determined using HPLC‐MS. The principal Daphne diterpene esters, yuanhuacine (1), yuanhuadine (2), yuanhuajine (3) and yuanhuagine (4), were isolated and identified using a combination of UV, IR, MS, 1H‐NMR and 13C‐NMR spectral data. Quantitative analysis indicated that 1 was the principal component in the root, and that 2 was the major component in the buds. The average extraction rates of 1 and 2 were 0.0151 and 0.0033% (n = 10) from the root, respectively, and 0.0020 and 0.0078% (n = 3) from the buds, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Nuchal translucency screening: how do women actually utilize the results?
Authors: Caughey Aaron B. , Musci Thomas J. , Belluomini Jenny , Main Denise , Otto Carl , Goldberg James 
Published: December 2006

AbstractObjectiveTo examine how women use the nuchal translucency (NT) risk adjustment in decision‐making for invasive prenatal diagnosis.Study DesignRetrospective cohort study of 1083 consecutive NT screening exams. A screen‐positive test was defined as a risk ≥ 1/300. Primary outcome was what proportion of screen‐positive or screen‐negative women chose to undergo chorionic villus sampling or amniocentesis.ResultsOf the women tested, 79% (858/1083) were ≥ 35‐years‐old and 88% (756/858) of these women had a decrease in age‐related risk after NT. Of the screen‐negative women, 31% (238/756) ≥ 35 years of age chose to have invasive testing as compared to only 11.2% (25/223) of those < 35 years of age (p < 0.001). Of the screen‐positive women, 71% (72/102) ≥ 35 years of age and 100% (2/2) < 35 years of age chose to obtain invasive testing (p = 0.368).ConclusionFirst‐trimester NT screening for Down syndrome (DS) enables a significant number of women over age 35 to lower the risk for DS several fold and avoid the risks of invasive testing. However, despite significant reductions in age‐specific mid‐trimester DS risks, a relatively high proportion of women ≥ 35 years of age still opted for invasive testing. Copyright © 2006 John Wiley & Sons, Ltd.
Computed tomographic reconstruction of a fetus with the dysgnathia complex (agnathia‐otocephaly)
Authors: Rajan Priya V. , Wing Deborah A. , Bocian Maureen , McKeown Anna 
Published: December 2006

AbstractThe dysgnathia complex (agnathia‐otocephaly) (AO) is a lethal malformation that consists of congenital absence of the lower jaw with union or close approximation of the lower ears on the front of the neck, microstomia, and hypoglossia. We present a novel case of agnathia‐otocephaly with associated organomegaly and the use of postmortem 3‐D computed tomographic rendering. Copyright © 2006 John Wiley & Sons, Ltd.
Optimization of phosphopeptide elution conditions in immobilized Fe(III) affinity chromatography
Authors: Imanishi Susumu Y. , Kochin Vitaly , Eriksson John E. 
Published: December 2006

AbstractWhile immobilized metal affinity chromatography (IMAC) has been widely used for affinity purification of phosphopeptides, the technique suffers from insufficient specificity. Therefore, there is an urgent need for IMAC optimization to yield the selectivity and sensitivity that is required for more challenging analyses. Recently, 2,5‐dihydroxybenzoic acid (DHB) and phosphoric acid mixture has been reported as an efficient IMAC eluant. The disadvantage of DHB is that is not suitable for electrospray ionization‐mass spectrometry. While further developing the IMAC elution protocol to overcome this problem, we noticed that DHB is not necessary and found a novel combination of phosphoric acid and acetonitrile to be more efficient. The purification efficacy of the novel protocol is superior to all previously described methods, while still being compatible with the most commonly used mass‐spectrometric techniques in phosphoproteomics.
Third‐generation amphiphilic conetworks. I. Synthesis and swelling behavior of poly(N,N‐dimethyl acrylamide)/polydimethylsiloxane conetworks
Authors: Erdodi G. , Kennedy J. P. 
Published: December 2006

AbstractA strategy has been developed for the synthesis of novel amphiphilic conetworks (APCNs) of poly(N,N‐dimethyl acrylamide) (PDMAAm) and polydimethyl‐siloxane (PDMS) segments crosslinked with polyhydrosiloxanes. The synthesis proceeds in three steps in one pot (see Figure 2 for reactions and abbreviations): (1) the preparation of a charge containing three components (an asymmetric–telechelic macromonomer, MA‐PDMS‐V, plus two symmetric–telechelic crosslinkers, MA‐PDMS‐MA and V‐PDMS‐V), (2) the free‐radical terpolymerization of N,N‐dimethyl acrylamide, MA‐PDMS‐V, and MA‐PDMS‐MA into a slightly crosslinked and soluble graft of a PDMAAm backbone carrying‐PDMS‐V branches, and (3) the crosslinking of PDMS branches with polyhydrosiloxanes. The effects of key experimental parameters (e.g., composition, molecular weights, and initiator and crosslinker concentrations) on synthesis details and swelling behavior have been studied. The water uptake/permeability of APCNs is significantly increased by the addition of homo‐PDMAAm to graft charges, crosslinking of the graft, and, after the desirable morphology is stabilized, removing the homo‐PDMAAm by water extraction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 295–307, 2007