bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of parallel acquisition techniques generalized autocalibrating partially parallel acquisitions (GRAPPA) and modified sensitivity encoding (mSENSE) in functional MRI (fMRI) at 3T
Authors: Preibisch Christine , Wallenhorst Tim , Heidemann Robin , Zanella Friedhelm E. , Lanfermann Heinrich 
Published: January 2008

AbstractPurposeTo evaluate the parallel acquisition techniques, generalized autocalibrating partially parallel acquisitions (GRAPPA) and modified sensitivity encoding (mSENSE), and determine imaging parameters maximizing sensitivity toward functional activation at 3T.Materials and MethodsA total of eight imaging protocols with different parallel imaging techniques (GRAPPA and mSENSE) and reduction factors (R = 1, 2, 3) were compared at different matrix sizes (64 and 128) with respect to temporal noise characteristics, artifact behavior, and sensitivity toward functional activation.ResultsEcho planar imaging (EPI) with GRAPPA and a reduction factor of 2 revealed similar image quality and sensitivity than full k‐space EPI. A higher incidence of artifacts and a marked sensitivity loss occurred at R = 3. Even though the same eight‐channel head coil was used for signal detection in all experiments, GRAPPA generally showed more benign patterns of spatially‐varying noise amplification, and mSENSE was also more susceptible to residual unfolding artifacts than GRAPPA.ConclusionAt 3T and a reduction factor of 2, parallel imaging can be used with only little penalty with regard to sensitivity. With our implementation and coil setup the performance of GRAPPA was clearly superior to mSENSE. Thus, it seems advisable to pay special attention to the employed parallel imaging method and its implementation. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
MRI‐guided interventions of the breast
Authors: Kaiser Werner A. , Pfleiderer Stefan O.R. , Baltzer Pascal A.T. 
Published: January 2008

AbstractMRI has proven to be a very reliable diagnostic tool in the detection and differential diagnosis of breast lesions. Some lesions are, even in retrospect, not detectable in x‐ray or ultrasound images but MRI is able to detect lesions at a much smaller size than the average size of lesions depicted by x‐ray and ultrasound. The aim in the future is to develop combined procedures where imaging, biopsy, and interventional therapies are combined in a single outpatient procedure. As a step toward this goal different interventional procedures are useful that include interstitial laser therapy (ILT), radiofrequency ablation (RFA), high‐intensity focused ultrasound (HIFU), microwave ablation therapy, and cryotherapy. In this overview the main features and initial results of these procedures are described and discussed. J. Magn. Reson. Imaging 2008;27:347–355. © 2008 Wiley‐Liss, Inc.
E protein dosage influences brain development more than family member identity
Authors: Ravanpay Ali C. , Olson James M. 
Published: January 2008

AbstractLoss‐of‐function studies have revealed the role of many basic helix‐loop‐helix (bHLH) transcription factors at specific points during development; however, the role of E proteins in the development of the nervous system has not been experimentally addressed. E proteins have been speculated to interact selectively with class II bHLH factors to form different neurogenic complexes. In this study, using coimmunoprecipitation in a culture model of neurogenesis (P19 cells), we show that E proteins E12, HEB, and E2‐2 interact with neuroD2. Using electrophoretic mobility shift assay and P19 cell culture, we show that these heterodimers bind a neuroD2 preferred E box and induce neurogenesis equally well. We examine the mRNA levels of the three E proteins at 10 time points during brain development and show that E protein gene expression is regulated such that at certain times during development selective interaction between neuroD2 and a single E protein (HEB) is a possibility. This led us to study the brains of HEB and E2A knockout mice, which manifest no gross neuroanatomical, cellular, or behavioral deficits. These findings, together with homology in the primary peptide sequence of E proteins, suggest functional compensation among E proteins during development of the nervous system. © 2008 Wiley‐Liss, Inc.
Hydroclimatic variability across the Susquehanna River Basin, USA, since the 17th century
Authors: Leathers Daniel J. , Malin Melissa L. , Kluver Daria B. , Henderson Gina R. , Bogart Tianna A. 
Published: January 2008

AbstractThe Susquehanna River Basin (SRB) is an extensive river drainage network that covers a total of 71 228 km2 in portions of New York, Pennsylvania, and Maryland, with more than 4 million inhabitants. It is the major source of fresh water to the USA's largest estuary, the Chesapeake Bay. Therefore, the hydroclimatic conditions within the SRB affect a large human population in addition to the ecological health of one of the world's most complicated and important estuarine environments.This research project seeks to document the hydroclimatic history of the SRB and to understand the relationships between global‐scale forcing mechanisms and the climatic variability of the Basin. Hydroclimatic variability since 1680 is documented through the reconstruction of temperature, precipitation, streamflow and a drought index using proxy and observational data. Results indicate that the hydroclimatic history of the SRB is very complex. Prior to the advent of European settlement, the SRB seems to have responded in concert with other landmasses within the North Atlantic Sector evidencing a regional manifestation of both the Medieval Warm Period and the Little Ice Age. Since the beginning of European settlement, the hydroclimate of the SRB has varied greatly on both inter‐annual and decadal time scales. The climatic variability of the SRB is found to be only weakly associated with large‐scale forcing mechanisms that are commonly assumed to influence the eastern USA. A notable exception is a strong temperature response associated with volcanic activity. Thus, regional forcings and land cover variations may play an important role in the hydroclimatic variability of this important river system. Copyright © 2008 Royal Meteorological Society
Using electrophoretic mobility and bead modeling to characterize the charge and secondary structure of peptides
Authors: Pei Hongxia , Xin Yao , Allison Stuart A. 
Published: January 2008

AbstractUsing a modeling methodology developed in our laboratory previously, the free solution electrophoretic mobilities of several peptides are examined to see what they can tell us about: (i) the pKas of specific side groups, and (ii) possible secondary structure. Modeling is first applied to mobility versus pH data of several small peptides (Messana, I. et al., J. Chromatogr. B 1997, 699, 149) where the only adjustable parameter associated with the charge state of the peptide is the pKa of the C‐terminal. In addition to examining this parameter, the question of possible secondary structure is addressed. For two of the peptides considered, GGNA and GGQA, it is possible to account for the observed mobilities using “random” models with little restriction on the allowed range of Phi–Psi angles. For GGRA and RPPGF, “compact” models (possibly involving an I‐turn) must be used to match modeling mobilities with experiment. Finally, three more complicated peptides ranging in size from 15 to 20 amino acids are also examined and characterized (Sitaram, B. R. et al., J. Chromatogr. A 1999, 857, 263). Here also, we find evidence of I‐turns or some other “compact” structure in two of the three peptides examined.
Prozess zur Anodisierung von Aluminiumbändern mit hoher elektrischer Durchschlagsspannung
Authors: Alisch G. , Wielage B. , Steinhäuser S. , Lampke Th. , Podlesak H. , Nickel D. 
Published: January 2008

AbstractDie Forschungsarbeiten hatten das Ziel, einen Prozess zu entwickeln, der die Erzeugung einer hohen elektrischen Durchschlagsfestigkeit in kürzester Prozesszeit auf Aluminiumbändern ermöglicht. Um in den Versuchen die Prozessparameter in einem breiten Bereich zu variieren, wurde gemeinsam mit der Fa. Steinert Elektromagnetbau GmbH Köln eine flexible diskontinuierliche Laboranlage konzipiert. Durch die Anwendung des Flüssigleiterprinzips ließ sich in diesem Equipment die in kontinuierlichen Anlagen praktizierte festkontaktfreie Anodisierung von Aluminiumbändern nachempfinden. Die Entwicklungsarbeiten konzentrierten sich auf die Gestaltung der Stromform. Anhand der Ergebnisse wird deutlich, dass es durch geeignete elektrische Parameter (Stromformen) in Verbindung mit einer entsprechenden Nachbehandlung möglich ist, höchste Durchschlagsspannungen in kürzester Prozesszeit zu erreichen. Die nach der neuen Technologie (Stromform TUCAL) erzeugten Schichten weisen zudem eine höhere Porendichte als die konventionell hergestellten auf, was sich in einer höheren Duktilität (geringeren Rissanfälligkeit) niederschlägt.
PVD – Eine Erfolgsgeschichte mit Zukunft
Authors: Bobzin K. , Bagcivan N. , Immich P. , Pinero C. , Goebbels N. , Krämer A. 
Published: January 2008

AbstractPVD‐Schichten (PVD: Physical Vapour Deposition) in Schichtdickenbereichen von wenigen Nanometern bis einigen Mikrometern sind aus den Ingenieurwissenschaften nicht mehr wegzudenken. PVD‐Schichten begegnen uns überall im täglichen Leben, als Datenspeicher auf CDs/DVDs, als Wärmedämmung auf Auto‐ und Architekturglas, als Diffusionsbarriere bei Lebensmittelverpackungen oder als dekorative Schichten für Schmuck, Armaturen und Accessoires. In den letzten 3 Jahrzehnten haben sich PVD‐Schichten in einer Vielzahl von technischen Anwendungen zum Verschleißschutz und zur Reibminderung etablieren können. Neben der eigentlichen Schichtentwicklung, zunächst für Werkzeuge später auch für Bauteile, wurden in der Vergangenheit zahlreiche Erfahrungen zur methodischen Produktentwicklung gesammelt. Die Oberfläche als modernes Konstruktionselement steht dabei noch ganz am Anfang des Möglichen. Die bisher erreichbare Leistungsfähigkeit beschichteter Bauteile kann noch erheblich gesteigert werden, wenn das tribologische System bestehend aus Schicht‐, Substratwerkstoff und Zwischenstoff, wie z. B. Schmiermittel, unter Berücksichtigung der Mikro‐ und Makrogeometrie für eine spezielle Anwendung optimal ausgelegt werden.Exemplarisch wird an einem Anwendungsbeispiel aus dem Sonderforschungsbereich (SFB) 442 „umweltverträgliche Tribosysteme”︁ der RWTH Aachen die Umsetzung von Ergebnissen aus der Grundlagenforschung bis hin zur industriellen Anwendung vorgestellt und an der industriellen PVD‐Marktentwicklung gespiegelt. In diesem Beispiel wird die Entwicklungsmethodik der Oberflächentechnik in der Prozesskette von der Fertigung bis zum Einsatztest des neuen Produktes dargestellt.
High‐resolution peripheral vein bypass graft wall studies using high sampling efficiency inner volume 3D FSE
Authors: Mitsouras Dimitris , Mulkern Robert V. , Owens Christopher D. , Conte Michael S. , Ersoy Hale , Luu Tuan M. , Whitmore Amanda G. , Creager Mark A. , Rybicki Frank J. 
Published: January 2008

AbstractA 3D inner‐volume fast spin echo (3D IV‐FSE) sequence was developed for ECG‐gated, black‐blood, T1‐ and T2‐weighted vessel wall imaging of peripheral vein bypass grafts (PVBG). The sequence utilizes nonselective refocusing excitations to minimize echo spacings and a highly selective IV excitation scheme to minimize the need for oversampling of z‐encode slice selections. The method was tested in eight PVBG patients who also underwent 2D FSE graft imaging. High‐quality 3D imaging was achieved in all subjects, with significant spatial resolution and volume coverage gains compared to the more conventional 2D FSE sequences normalized for signal‐to‐noise ratios (SNRs) and scan times. Compared to previously proposed 3D IV‐FSE methods, nonselective refocusing resulted in a more than 20% FSE echo train sampling efficiency increase while the use of highly selective IV excitation resulted in a 30% improvement in slice oversampling efficiency. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Metabolic changes in the thalamus after spinal cord injury followed by proton MR spectroscopy
Authors: Likavčanová Katarína , Urdzíková Lucia , Hájek Milan , Syková Eva 
Published: January 2008

AbstractOur study followed the changes in thalamic nuclei metabolism, hindlimb sensitivity to thermal stimulation, and locomotor function after spinal cord injury (SCI). MR spectroscopy (MRS) was used to examine the thalamic nuclei of rats 1 day before and 1, 3, 6, and 15 days after SCI or sham surgery. All animals were tested before MRS measurements for motor performance and thermal sensitivity. SCI induced by balloon compression caused complete paraplegia from the first to third day, followed by partial functional recovery during the second week. MRS revealed an increase in N‐acetylaspartate (NAA) concentration in the thalamic nuclei on the first day after SCI, which decreased by the third day. The data also showed an increase in inositol (Ins), glutamate, and creatine (Cr) concentrations on the third day postinjury; the Ins concentration remained elevated on the sixth day. In sham‐operated animals an increase in NAA concentration was observed on the sixth and fifteenth days after surgery and an increase in Cr concentration on the third day. A positive correlation between Ins concentration and hindlimb sensitivity in both SCI and sham‐operated animals suggests changes in glial activity, while changes in NAA levels may indicate the response of thalamic neuronal cells to injury. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Structural materials underpinning functional materials: teaching old dogs new tricks
Authors: MacDonald William A 
Published: January 2008

Abstract‘Structural’ polymers are finding new applications underpinning new technology developments based on functional polymers. This paper discusses the use of polyester films as base substrates for flexible electronic applications based on conjugated polymers and low‐temperature hydrogenated amorphous silica processing, and discusses the challenges involved in successfully developing substrates ‘fit for purpose’. Copyright © 2008 Society of Chemical Industry
Molecular weight dependence of phase behavior of PEO/P(EO‐b‐DMS) blends: Application of Sanchez‐Lacombe lattice fluid theory
Authors: Li Hongfei , Jiang Shichun , Sun Zhaoyan , An Lijia 
Published: January 2008

AbstractMolecular weight dependence of phase separation behavior of the Poly (ethylene oxide) (PEO)/Poly(ethylene oxide‐block‐dimethylsiloxane) (P(EO‐b‐DMS)) blends was investigated by both experimental and theoretical methods. The cloud point curves of PEO/P(EO‐b‐DMS) blends were obtained by turbidity method. Based on Sanchez‐Lacombe lattice fluid theory (SLLFT), the adjustable parameter, $ {{\varepsilon _{12}^\ast } \mathord{\left/ {\vphantom {{\varepsilon _{12}^* } k}} \right. \kern-\nulldelimiterspace} k} $ (quantifying the interaction energy between different components), was evaluated by fitting the experimental data in phase diagrams. To calculate the spinodals, binodals, and the volume changes of mixing for these blends, three modified combining rules of the scaling parameters for the block copolymer were introduced. The calculated binodals with those modified combining rules show good agreement with the experimental data. Furthermore, the calculated volume changes during mixing decrease with increasing molecular weight of PEO, and the relationship between the volume changes and temperature is quite different for the mixtures with different molecular weight of PEO. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 452–459, 2008
Sitagliptin: first DPP‐4 inhibitor to treat type 2 diabetes
Authors: Chaplin Steve , Krentz Andrew 
Published: January 2008

AbstractSitagliptin (Januvia) is the first of a new class of drugs in the treatment of type 2 diabetes. Here, Steve Chaplin presents the clinical data relating to its efficacy and adverse effects, and Dr Krentz comments on its potential place in the treatment of type 2 diabetes. Copyright © 2008 Wiley Interface Ltd
An exploratory comparative study of volatile compounds in exhaled breath and emitted by skin using selected ion flow tube mass spectrometry
Authors: Turner Claire , Parekh Bhavin , Walton Christopher , Španěl Patrik , Smith David , Evans Mark 
Published: January 2008

AbstractSelected ion flow tube mass spectrometry (SIFT‐MS) has been used to carry out a pilot parallel study on five volunteers to determine changes occurring in several trace compounds present in exhaled breath and emitted from skin into a collection bag surrounding part of the arm, before and after ingesting 75 g of glucose in the fasting state. SIFT‐MS enabled real‐time quantification of ammonia, methanol, ethanol, propanol, formaldehyde, acetaldehyde, isoprene and acetone. Following glucose ingestion, blood glucose and trace compound levels were measured every 30 min for 2 h. All the above compounds, except formaldehyde, were detected at the expected levels in exhaled breath of all volunteers; all the above compounds, except isoprene, were detected in the collection bag. Ammonia, methanol and ethanol were present at lower levels in the bag than in the breath. The aldehydes were present at higher levels in the bag than in breath. The blood glucose increased to a peak about 1 h post‐ingestion, but this change was not obviously correlated with temporal changes in any of the compounds in breath or emitted by skin, except for acetone. The decrease in breath acetone was closely mirrored by skin‐emitted acetone in three volunteers. Breath and skin acetone also clearly change with blood glucose and further work may ultimately enable inferences to be drawn of the blood glucose concentration from skin or breath measurements in type 1 diabetes. Copyright © 2008 John Wiley & Sons, Ltd.
The influence of prior knowledge on viewing and interpreting graphics with macroscopic and molecular representations
Authors: Cook Michelle , Wiebe Eric N. , Carter Glenda 
Published: January 2008

AbstractPrevious research has indicated that the use of multiple representations with macroscopic and molecular features can improve conceptual understanding; however, the influence of prior knowledge of the domain cannot be overlooked. Using eye‐tracking technology and sequential analysis, this study investigated how high school students (n = 54) with different levels of prior knowledge transitioned among the macroscopic and molecular representations of the selected cell transport graphics. The results indicated that high prior knowledge students transitioned more frequently between the molecular representations, whereas low prior knowledge students transitioned more frequently between the macroscopic representations. These findings suggest that students with high prior knowledge distributed their visual attention on conceptually relevant features, whereas low prior knowledge students focused on surface features. In addition, low prior knowledge students transitioned more frequently between macroscopic and molecular representations, suggesting that these students were experiencing more difficulty as they were coordinating the representations. Because these students were using surface features to create linkages between the representations, they were unable to understand the underlying themes. More research on the differences in the distribution of visual attention among learners can provide further insight as to the difficulties low prior knowledge students face when interpreting multiple representations. © 2008 Wiley Periodicals, Inc. Sci Ed 92:848–867, 2008
Probabilistic Analysis of Process Economics
Authors: Deissenboeck Florian , Pizka Markus 
Published: January 2008

AbstractThe economic benefit of a certain development process or particular activity is usually unknown and indeed hard to predict. However, the cost‐effectiveness of process improvements is of paramount importance and the question how profitable certain activities are needs to be answered. Within a large‐scale commercial organization, we were challenged with the task to quantify the economic benefit of isolated test and development environments. To answer this question, we defined a generic process model based on absorbing Markov chains that allows the analyzation of the economic benefit of software process variations. This model exposes conflicts between process steps and reiterations of development activities and thereby provides a highly flexible tool for the investigation of the effects of changes to a development process on its overall performance. This model was used to predict the impact of isolated testing on the overall effort and duration of projects. The results obtained correspond well with the perception of experienced developers and gives a detailed explanation for the effects. Besides this, it can be used to analyze various other economic aspects of software development processes and yields an interesting alternative for cost estimation. Copyright © 2008 John Wiley & Sons, Ltd.
Continuous process improvement at a large software organization
Authors: Malheiros Viviane , Paim Fábio Rilston , Mendonça Manoel 
Published: January 2008

AbstractDesigning software processes for large enterprises is a hard task, but evolving this process can be even harder. As large companies increasingly invest in software process improvement, they have to face typical problems regarding software process evolution within such environments in order to guarantee their software process survival. This article describes experiences and lessons learned at Serpro, the largest government owned software company in Latin America, while defining its organizational standard software process and fostering its continuous evolution. Copyright © 2008 John Wiley & Sons, Ltd.
Quality assurance for TTCN‐3 test specifications
Authors: Neukirchen Helmut , Zeiss Benjamin , Grabowski Jens , Baker Paul , Evans Dominic 
Published: January 2008

AbstractComprehensive testing of modern communication systems often requires large and complex test suites, which have to be maintained throughout the system life cycle. Industrial experience, with those written using the standardized Testing and Test Control Notation (TTCN‐3), has shown that this maintenance is a non‐trivial task and its burden can be reduced by means of appropriate concepts and tool support. To this aim, Motorola has collaborated with the University of Göttingen to develop TRex, an open‐source TTCN‐3 development environment, which notably provides suitable metrics and refactorings to enable the assessment and automatic restructuring of test suites. This article presents concepts like metrics and refactoring for the quality assurance of TTCN‐3 test suites and their implementation provided by the TRex tool. These means make it far easier to construct and maintain TTCN‐3 tests that are concise and optimally balanced with respect to maintainability quality characteristics. Copyright © 2008 John Wiley & Sons, Ltd.