bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interventional MR elastography for MRI‐guided percutaneous procedures
Authors: Corbin Nadège , Vappou Jonathan , Breton Elodie , Boehler Quentin , Barbé Laurent , Renaud Pierre , de Mathelin Michel 
Published: April 2015

PurposeMRI‐guided thermal ablations require reliable monitoring methods to ensure complete destruction of the diseased tissue while avoiding damage to the surrounding healthy tissue. Based on the fact that thermal ablations result in substantial changes in biomechanical properties, interventional MR elastography (MRE) dedicated to the monitoring of MR‐guided thermal therapies is proposed here.MethodsInterventional MRE consists of a needle MRE driver, a fast and interactive gradient echo pulse sequence with motion encoding, and an inverse problem solver in real‐time. This complete protocol was tested in vivo on swine and the ability to monitor elasticity changes in real‐time was assessed in phantom.ResultsThanks to a short repetition time, a reduction of the number of phase‐offsets and the use of a sliding window, one refreshed elastogram was provided every 2.56 s for an excitation frequency of 100 Hz. In vivo elastograms of swine liver were successfully provided in real‐time during one breath‐hold. Changes of elasticity were successfully monitored in a phantom during its gelation with the same elastogram frame rate.ConclusionThis study demonstrates the ability of detecting elasticity changes in real‐time and providing elastograms in vivo with interventional MRE that could be used for the monitoring of thermal ablations. Magn Reson Med 75:1110–1118, 2016. © 2015 Wiley Periodicals, Inc.
Quantification of turbulence and velocity in stenotic flow using spiral three‐dimensional phase‐contrast MRI
Authors: Petersson Sven , Dyverfeldt Petter , Sigfridsson Andreas , Lantz Jonas , Carlhäll Carl‐Johan , Ebbers Tino 
Published: April 2015

PurposeEvaluate spiral three‐dimensional (3D) phase contrast MRI for the assessment of turbulence and velocity in stenotic flow.MethodsA‐stack‐of‐spirals 3D phase contrast MRI sequence was evaluated in vitro against a conventional Cartesian sequence. Measurements were made in a flow phantom with a 75% stenosis. Both spiral and Cartesian imaging were performed using different scan orientations and flow rates. Volume flow rate, maximum velocity and turbulent kinetic energy (TKE) were computed for both methods. Moreover, the estimated TKE was compared with computational fluid dynamics (CFD) data.ResultsThere was good agreement between the turbulent kinetic energy from the spiral, Cartesian and CFD data. Flow rate and maximum velocity from the spiral data agreed well with Cartesian data. As expected, the short echo time of the spiral sequence resulted in less prominent displacement artifacts compared with the Cartesian sequence. However, both spiral and Cartesian flow rate estimates were sensitive to displacement when the flow was oblique to the encoding directions.ConclusionSpiral 3D phase contrast MRI appears favorable for the assessment of stenotic flow. The spiral sequence was more than three times faster and less sensitive to displacement artifacts when compared with a conventional Cartesian sequence. Magn Reson Med 75:1249–1255, 2016. © 2015 Wiley Periodicals, Inc.
Spectrally selective imaging with wideband balanced steady‐state free precession MRI
Authors: Çukur Tolga 
Published: April 2015

PurposeUnwanted, bright fat signals in balanced steady‐state free precession sequences are commonly suppressed using spectral shaping. Here, a new spectral‐shaping method is proposed to significantly improve the uniformity of stopband suppression without compromising the level of passband signals.MethodsThe proposed method combines binomial‐pattern excitation pulses with a wideband balanced steady‐state free precession sequence kernel. It thereby increases the frequency separation between the centers of pass and stopbands by π radians, enabling improved water‐fat contrast. Simulations were performed to find the optimal flip angles and subpulse spacing for the binomial pulses that maximize contrast and signal efficiency.ResultsComparisons with a conventional binomial balanced steady‐state free precession sequence were performed in simulations as well as phantom and in vivo experiments at 1.5 T and 3 T. Enhanced fat suppression is demonstrated in vivo with an average improvement of 58% in blood‐fat and 68% in muscle‐fat contrast (P < 0.001, Wilcoxon signed‐rank test).ConclusionThe proposed binomial wideband balanced steady‐state free precession method is a promising candidate for spectrally selective imaging with enhanced reliability against field inhomogeneities. Magn Reson Med 75:1132–1141, 2016. © 2015 Wiley Periodicals, Inc.
A novel approach to tracer‐kinetic modeling for (macromolecular) dynamic contrast‐enhanced MRI
Authors: Jacobs Igor , Strijkers Gustav J. , Keizer Henk M. , Janssen Henk M. , Nicolay Klaas , Schabel Matthias C 
Published: April 2015

PurposeTo develop a novel tracer‐kinetic modeling approach for multi‐agent dynamic contrast‐enhanced MRI (DCE‐MRI) that facilitates separate estimation of parameters characterizing blood flow and microvascular permeability within one individual.MethodsMonte Carlo simulations were performed to investigate the performance of the constrained multi‐agent model. Subsequently, multi‐agent DCE‐MRI was performed on tumor‐bearing mice (n = 5) on a 7T Bruker scanner on three measurement days, in which two dendrimer‐based contrast agents having high and intermediate molecular weight, respectively, along with gadoterate meglumine, were sequentially injected within one imaging session. Multi‐agent data were simultaneously fit with the gamma capillary transit time model. Blood flow, mean capillary transit time, and bolus arrival time were constrained to be identical between the boluses, while extraction fractions and washout rate constants were separately determined for each agent.ResultsSimulations showed that constrained multi‐agent model regressions led to less uncertainty and bias in estimated tracer‐kinetic parameters compared with single‐bolus modeling. The approach was successfully applied in vivo, and significant differences in the extraction fraction and washout rate constant between the agents, dependent on their molecular weight, were consistently observed.ConclusionA novel multi‐agent tracer‐kinetic modeling approach that enforces self‐consistency of model parameters and can robustly characterize tumor vascular status was demonstrated. Magn Reson Med 75:1142–1153, 2016. © 2015 Wiley Periodicals, Inc.
Lowering the B1 threshold for improved BEARB1 mapping
Authors: Jordanova Kalina V. , Nishimura Dwight G. , Kerr Adam B. 
Published: April 2015

PurposeAccurate measurement of the nonuniform transmit radiofrequency field is necessary for magnetic resonance imaging applications. The radiofrequency field excitation amplitude (B1) is often obtained by acquiring a B1 map. We modify the B1 estimation using adiabatic refocusing (BEAR) method to extend its range to lower B1 magnitudes.Theory and MethodsThe BEAR method is a phase‐based B1 mapping method, wherein hyperbolic secant pulses induce a phase sensitivity to B1. The measurable B1 range is limited due to the adiabatic threshold of the pulses. We redesign the method to use flattened hyperbolic secant pulses, which have lower adiabatic thresholds. We optimize the flattened hyperbolic secant parameters to minimize phase sensitivity to frequency variations.ResultsWe validate the performance of the new method via simulation and in vivo at 3T, and show that for
, accurate B1 maps can be acquired using reduced nominal peak B1 values.ConclusionThe adiabatic threshold for the BEAR method is reduced with flattened hyperbolic secant pulses, which are optimized for accurate phase‐to‐B1 mapping over a frequency range, and allow for lower nominal B1 values. At 3T, the nominal B1 is decreased by 52% and the sensitivity to B1 is increased by a factor of 3.8. This can improve the method's applicability for measurement of low B1. Magn Reson Med 75:1262–1268, 2016. © 2015 Wiley Periodicals, Inc.
T2 relaxation times are increased in Skeletal muscle of DMD but not BMD patients
Authors: Wokke Beatrijs H. , Van Den Bergen Janneke C. , Hooijmans Melissa T. , Verschuuren Jan J. , Niks Erik H. , Kan Hermien E. 
Published: April 2015

ABSTRACTIntroductionExon‐skipping drugs in Duchenne muscular dystrophy (DMD) aim to restore truncated dystrophin expression, which is present in the milder Becker muscular dystrophy (BMD). MRI skeletal muscle T2 relaxation times as a representation of edema/inflammation could be quantitative outcome parameters for such trials. Methods: We studied T2 relaxation times, adjusted for muscle fat fraction using Dixon MRI, in lower leg muscles of DMD and BMD patients and healthy controls. Results: T2 relaxation times correlated significantly with fat fractions in patients only (P < 0.001). After adjusting for muscle fat, T2 relaxation times were significantly increased in 6 muscles of DMD patients (P < 0.01), except for the extensor digitorum longus. In BMD, T2 relaxation times were unchanged. Conclusions: T2 relaxation times could be a useful outcome parameter in exon‐skipping trials in DMD but are influenced by fat despite fat suppression. This should be accounted for when using quantitative T2 mapping to investigate edema/inflammation. Muscle Nerve 53: 38–43, 2016
Effects of preferential etching treatment of CZTS absorber layer by deionized water
Authors: Miyazaki H. , Aono M. , Kishimura H. , Katagiri H. 
Published: April 2015

AbstractCu2ZnSnS4 (CZTS) is one of the promising materials for high efficiency thin film solar cells. Here we report on the chemical and structural characterization of the CZTS thin films before and after the surface treatment using deionized water. X‐ray diffraction and Raman scattering spectroscopy results showed that the deionized water treatment did not affect the bulk characterization. Copper chemical composition ratio increases and sulphur composition ratio decreases with increasing deionized water treatment temperature on the film surface. In the case of the sample treated at 353 K, the surface composition changes to Cu‐rich composition. However, the chemical composition ratio of the bulk still remained before deionized water (DIW) surface treatment. The change in the CZTS surface composition according to the DIW surface treatment temperature, we think these results may help to be studied in CZTS surface in more detail. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Making the news: Heterogeneous media coverage and corporate litigation
Authors: Tan David 
Published: April 2015

Research summary: This study explores how relative prominence shapes rivalry between firms. Corporate litigation, an increasingly costly domain of interfirm rivalry, is threatening not just because of the immediate legal stakes but because of the indirect losses that unwanted negative publicity inflicts on defendants. I argue that potential defendants' incentives to avoid such losses create a source of value that firms can capture by agreeing to forgo litigation. The more prominent a firm is relative to rivals, the greater its threat and the more value it stands to capture from potential targets by sparing them from litigation.Managerial summary: The power to attract media attention can be valuable to firms beyond its role in managing relations with investors or the public. It can also provide leverage against industry rivals. Being sued by a prominent firm carries the threat of potential damaging publicity, especially for lesser‐known rivals. Firms may be able to leverage this threat to elicit concessions in return for sparing rivals from litigation. Prominent firms stand to benefit not just from eliciting concessions from rivals but from the ability to do so while avoiding costly litigation. Data from the semiconductor industry show that firms that command much higher levels of media coverage than rivals are able to avoid litigation more often than firms with comparable or lower levels of media coverage. Copyright © 2015 John Wiley & Sons, Ltd.
Molecular signature of erythroblast enucleation in human embryonic stem cells
Authors: Rouzbeh Shaghayegh , Kobari Ladan , Cambot Marie , Mazurier Christelle , Hebert Nicolas , Faussat Anne-Marie , Durand Charles , Douay Luc , Lapillonne Hélène 
Published: April 2015

Abstract
While enucleation is a critical step in the terminal differentiation of human red blood cells, the molecular mechanisms underlying this unique process remain unclear. To investigate erythroblast enucleation, we studied the erythroid differentiation of human embryonic stem cells (hESCs), which provide a unique model for deeper understanding of the development and differentiation of multiple cell types. First, using a two-step protocol, we demonstrated that terminal erythroid differentiation from hESCs is directly dependent on the age of the embryoid bodies. Second, by choosing hESCs in two extreme conditions of erythroid culture, we obtained an original differentiation model which allows one to study the mechanisms underlying the enucleation of erythroid cells by analyzing the gene and miRNA (miR) expression profiles of cells from these two culture conditions. Third, using an integrated analysis of mRNA and miR expression profiles, we identified five miRs potentially involved in erythroblast enucleation. Finally, by selective knockdown of these five miRs we found miR-30a to be a regulator of erythroblast enucleation in hESCs. Stem Cells 2015;33:2431–2441
Coverage‐based regression test case selection, minimization and prioritization: a case study on an industrial system
Authors: Di Nardo Daniel , Alshahwan Nadia , Briand Lionel , Labiche Yvan 
Published: April 2015

SummaryThis paper presents a case study of coverage‐based regression testing techniques on a real world industrial system with real regression faults. The study evaluates four common prioritization techniques, a test selection technique, a test suite minimization technique and a hybrid approach that combines selection and minimization. The study also examines the effects of using various coverage criteria on the effectiveness of the studied approaches. The results show that prioritization techniques that are based on additional coverage with finer grained coverage criteria perform significantly better in fault detection rates. The study also reveals that using modification information in prioritization techniques does not significantly enhance fault detection rates. The results show that test selection does not provide significant savings in execution cost (<2%), which might be attributed to the nature of the changes made to the system. Test suite minimization using finer grained coverage criteria could provide significant savings in execution cost (79.5%) while maintaining a fault detection capability level above 70%, thus representing a possible trade‐off. The hybrid technique did not provide a significant improvement over traditional minimization techniques. Copyright © 2015 John Wiley & Sons, Ltd.
Azadirachtin, a neem‐derived biopesticide, impairs behavioral and hematological parameters in carp (Cyprinus carpio)
Authors: Murussi Camila R. , Menezes Charlene C. , Nunes Mauro E. M. , Araújo Maria do Carmo S. , Quadros Vanessa A. , Rosemberg Denis B. , Loro Vania L. 
Published: April 2015

ABSTRACTAzadirachtin (Aza) is a promisor biopesticide used in organic production and aquaculture. Although this compound is apparently safe, there is evidence that it may have deleterious effects on fish. Behavioral and hematological tests are grouped into a set of parameters that may predict potential toxicity of chemical compounds. Here, we investigate the effects of Aza, in the commercial formulation Neenmax™, on carp (Cyprinus carpio) by defining LC50 (96 h), and testing behavioral and hematological parameters. In our study, LC50 was estimated at 80 μL/L. We exposed carp to Aza at 20, 40, and 60 μL/L, values based on 25, 50, and 75% of LC50, respectively. At 60 μL/L, Aza promoted significant changes in several parameters, increasing the distance traveled and absolute turn angle. In addition, the same concentration decreased the time spent immobile and the number of immobile episodes. Hematological parameters, such as hematocrit, hemoglobin, hematimetrics index, and red cell distribution, were decreased at 60 μL/L Aza exposure. In conclusion, our study demonstrates that 60 μL/L Aza altered locomotor activity, motor pattern, and hematological parameters, suggesting potential toxicity to carp after acute exposure. In addition, this is the first report that evaluates the actions of a chemical contaminant using automated behavioral tracking of carp, which may be a useful tool for assessing the potential toxicity of biopesticides in conjunction with hematological tests. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1381–1388, 2016.
Nonylphenol diethoxylate inhibits apoptosis induced in PC12 cells
Authors: Liu Chuang , Sun Yongkun , Song Yutong , Saito Takeshi , Kurasaki Masaaki 
Published: April 2015

ABSTRACTNonylphenol and short‐chain nonylphenol ethoxylates such as NP2EO are present in aquatic environment as wastewater contaminants, and their toxic effects on aquatic species have been reported. Apoptosis has been shown to be induced by serum deprivation or copper treatment. To understand the toxicity of nonylphenol diethoxylate, we investigated the effects of NP2EO on apoptosis induced by serum deprivation and copper by using PC12 cell system. Nonylphenol diethoxylate itself showed no toxicity and recovered cell viability from apoptosis. In addition, nonylphenol diethoxylate decreased DNA fragmentation caused by apoptosis in PC12 cells. This phenomenon was confirmed after treating apoptotic PC12 cells with nonylphenol diethoxylate, whereas the cytochrome c release into the cytosol decreased as compared to that in apoptotic cells not treated with nonylphenol diethoxylates. Furthermore, Bax contents in apoptotic cells were reduced after exposure to nonylphenol diethoxylate. Thus, nonylphenol diethoxylate has the opposite effect on apoptosis in PC12 cells compared to nonylphenol, which enhances apoptosis induced by serum deprivation. The difference in structure of the two compounds is hypothesized to be responsible for this phenomenon. These results indicated that nonylphenol diethoxylate has capability to affect cell differentiation and development and has potentially harmful effect on organisms because of its unexpected impact on apoptosis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1389–1398, 2016.
An algebraic theory for web service contracts
Authors: Laneve Cosimo , Padovani Luca 
Published: April 2015

Abstract

We study the foundations of Web service technologies for connecting abstract and concrete service definitions and for discovering services according to their observable behavior. We pursue this study addressing a subset of BPEL activities that include concurrency constructs. We present a formal semantics—called
compliance preorder
—of this subset of BPEL and we define a behavioral type discipline that guarantees the correctness of client-server interactions. The types of our discipline, called
contracts
, are De Nicola and Hennessy tau-less, finite-state CCS processes. We show that contracts are BPEL normal forms according to the compliance preorder and that the compliance preorder does coincide with a well-known equivalence in concurrency theory, the
must-testing preorder
. The compliace preorder is not fully adequate for discovering Web services though, since it does not support width and depth extensions of Web services. To address this issue, we propose a sound generalization of the compliance preorder, called
subcontract relation
, that admits a notion of principal service contract—the
dual contract
—compliant with a given client contract and that exhibits good precongruence properties when choreographies of Web services are considered.
Investigation into the misincorporation of norleucine into a recombinant protein vaccine candidate
Authors: Ni Joyce , Gao Meg , James Andrew , Yao Jiansheng , Yuan Tao , Carpick Bruce , D’Amore Tony , Farrell Patrick 
Published: April 2015

Abstract
A high level of norleucine misincorporation was detected in a recombinant methionine-rich protein vaccine candidate expressed in E. coli K12. An investigation was conducted to evaluate a simple remediation strategy to reduce norleucine misincorporation and to determine if the phenomenon was either (a) due to the depletion of methionine during fermentation, (b) a result of the cultivation environment, or (c) a strain-specific effect. While supplementation with exogenous methionine improved product quality, the undesirable biosynthesis of non-standard amino acids such as norleucine and norvaline persisted. In contrast, non-standard amino acid biosynthesis was quickly minimized upon selection of an appropriate fed-batch process control strategy, fermentation medium, and nutrient feed. By expressing the same protein in E. coli BL21(DE3), it was determined that the biosynthesis of norleucine and norvaline, and the misincorporation of norleucine into the protein were primarily attributed to the use of E. coli K12 as the host for protein expression.
Making Big Communities Small: Using Network Science to Understand the Ecological and Behavioral Requirements for Community Social Capital
Authors: Neal Zachary 
Published: April 2015

AbstractThe concept of social capital is becoming increasingly common in community psychology and elsewhere. However, the multiple conceptual and operational definitions of social capital challenge its utility as a theoretical tool. The goals of this paper are to clarify two forms of social capital (bridging and bonding), explicitly link them to the structural characteristics of small world networks, and explore the behavioral and ecological prerequisites of its formation. First, I use the tools of network science and specifically the concept of small‐world networks to clarify what patterns of social relationships are likely to facilitate social capital formation. Second, I use an agent‐based model to explore how different ecological characteristics (diversity and segregation) and behavioral tendencies (homophily and proximity) impact communities’ potential for developing social capital. The results suggest diverse communities have the greatest potential to develop community social capital, and that segregation moderates the effects that the behavioral tendencies of homophily and proximity have on community social capital. The discussion highlights how these findings provide community‐based researchers with both a deeper understanding of the contextual constraints with which they must contend, and a useful tool for targeting their efforts in communities with the greatest need or greatest potential.