bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uniaxial Strain Effect of the Moderately Dimerized Molecular Conductor β‐(meso‐DMBEDT‐TTF)2PF6
Authors: Nishida Yohei , Isono Takayuki , Ueda Akira , Mori Hatsumi 
Published: July 2014

AbstractThe anisotropic band structure and electrical resistivity under uniaxial strain were investigated for the moderately dimerized molecular conductor β‐(meso‐DMBEDT‐TTF)2PF6 [DMBEDT‐TTF = dimethylbis(ethylenedithio)tetrathiafulvalene], which has an intermediate electronic state between 3/4‐filled and effective 1/2‐filled band structures at ambient pressure. The calculated energy overlap of the upper and lower bands increased more rapidly by applying uniaxial strain along the c axis than along the (a–b) axis towards the 3/4‐filled band structure, which is related to intersite electronic correlation, and the energy gap between these bands is estimated to be larger with application of uniaxial strain along the (a+b) axis towards an effective 1/2‐filled band structure, which is related to intrasite electronic correlation. The electrical resistivity under uniaxial strain along the c axis indicates the semiconducting behavior from 300 K and the superconducting (SC) transitions at 4.6–2.8 K under 0.10–0.41 GPa. On the other hand, the metal–insulator transition is not completely suppressed up to 0.8 GPa and SC transitions appear at 4.5–2.6 K under 0.16–0.45 GPa with uniaxial strain along the (a–b) axis. If this uniaxial strain results in semiconducting behavior and positive magnetoresistance related to intersite correlation, the SC states are observed under hydrostatic pressure, which indicates that the SC state is deeply related to the charge‐ordered state.
N‐Heterocyclic Carbene Catalysis as a Tool for Gaining Access to the 3,4‐Dihydropyran‐2‐one Skeleton
Authors: Albanese Domenico C. M. , Gaggero Nicoletta 
Published: July 2014

AbstractAn overview of the progress made in the synthesis of 3,4‐dihydropyran‐2‐ones since the development of NHC catalysis is reported. Two distinct classes of species – electrophilic α,β‐unsaturated acylazolium and nucleophilic azolium enol/enolate intermediates – can easily be produced from different substrates through the intermediacy of NHC catalysis. They enable the construction of the 3,4‐dihydropyran‐2‐one skeleton, the core of natural and synthetic products with significant biological activities, through Michael additions, cycloadditions and rearrangements.
Oxidative toxicity of perfluorinated chemicals in green mussel and bioaccumulation factor dependent quantitative structure–activity relationship
Authors: Liu Changhui , Chang Victor W.C. , Gin Karina Y.H. 
Published: July 2014

Abstract

Concerns regarding perfluorinated chemicals (PFCs) have risen in recent years because of their ubiquitous presence and high persistency. However, data on the environmental impacts of PFCs on marine organisms are very limited. Oxidative toxicity has been suggested to be one of the major toxic pathways for PFCs to induce adverse effects on organisms. To investigate PFC–induced oxidative stress and oxidative toxicity, a series of antioxidant enzyme activities and oxidative damage biomarkers were examined to assess the adverse effects of the following 4 commonly detected compounds: perfluoro-octanesulfonate, perfluoro-ocanoic acid, perfluorononanoic acid, and perfluorodecanoic acid, on green mussel (Perna viridis). Quantitative structure–activity relationship (QSAR) models were also established. The results showed that all the tested PFCs are able to induce antioxidant response and oxidative damage on green mussels in a dose-dependent manner. At low exposure levels (0 µg/L–100 µg/L), activation of antioxidant enzymes (catalase [CAT] and superoxide dismutase [SOD]) was observed, which is an adaptive response to the excessive reactive oxygen species induced by PFCs, while at high exposure levels (100 µg/L–10 000 µg/L), PFCs were found to inhibit some enzyme activity (glutathione S-transferase and SOD) where the organism's ability to respond in an adaptive manner was compromised. The oxidative stress under high PFC exposure concentration also led to lipid and DNA damage. PFC–induced oxidative toxicity was found to be correlated with the bioaccumulation potential of PFCs. Based on this relationship, QSAR models were established using the bioaccumulation factor (BAF) as the molecular descriptor for the first time. Compared with previous octanol–water partition coefficient–dependent QSAR models, the BAF-dependent QSAR model is more suitable for the impact assessment of PFCs and thus provides a more accurate description of the toxic behavior of these compounds. Environ Toxicol Chem 2014;33:2323–2332. © 2014 SETAC
Aqueous and lipid nuclear magnetic resonance metabolomic profiles of the earthworm Aporrectodea caliginosa show potential as an indicator species for environmental metabolomics
Authors: Brown Jeffrey N. , Samuelsson Linda , Bernardi Giuliana , Gooneratne Ravi , Larsson D.G. Joakim 
Published: July 2014

Abstract

The common pasture earthworm Aporrectodea caliginosa has often been neglected in environmental metabolomics in favor of species easily bred in the laboratory. The present study assigns aqueous metabolites in A. caliginosa using high-resolution 1- and 2-dimensional nuclear magnetic resonance (NMR) spectroscopy. In total, 51 aqueous metabolites were identified, including typical amino acids (alanine, leucine, asparagine, phenylalanine), sugars (maltose, glucose), the dominant earthworm-specific 2-hexyl-5-ethyl-furansulfonate, and several previously unreported metabolites (oxoglutarate, putrescine). Examining the lesser-known earthworm lipid metabolome showed various lipid fatty acyl chains, cholesterol, and phosphatidylcholine. To briefly test if the NMR metabolomic techniques could differentiate A. caliginosa from different sites, earthworms were collected from 2 adjacent farms. Orthogonal partial least squares discriminant analysis detected metabolomic differences, suggesting the worms from the 2 sites differed in their energy metabolism, as indicated by altered levels of alanine, glutamine, glutamate, malate, fumarate, and lipids. Evidence of greater utilization of lipid energy reserves and onset of protein catabolism was also present. While the precise cause of the metabolomic differences could not be determined, the results show the potential of this species for further environmental metabolomic studies. Environ Toxicol Chem 2014;33:2313–2322. © 2014 SETAC
An investigation of positive and inverted hemodynamic response functions across multiple visual areas
Authors: Puckett Alexander M. , Mathis Jedidiah R. , DeYoe Edgar A. 
Published: July 2014

AbstractRecent studies have demonstrated significant regional variability in the hemodynamic response function (HRF), highlighting the difficulty of correctly interpreting functional MRI (fMRI) data without proper modeling of the HRF. The focus of this study was to investigate the HRF variability within visual cortex. The HRF was estimated for a number of cortical visual areas by deconvolution of fMRI blood oxygenation level dependent (BOLD) responses to brief, large‐field visual stimulation. Significant HRF variation was found across visual areas V1, V2, V3, V4, VO‐1,2, V3AB, IPS‐0,1,2,3, LO‐1,2, and TO‐1,2. Additionally, a subpopulation of voxels was identified that exhibited an impulse response waveform that was similar, but not identical, to an inverted version of the commonly described and modeled positive HRF. These voxels were found within the retinotopic confines of the stimulus and were intermixed with those showing positive responses. The spatial distribution and variability of these HRFs suggest a vascular origin for the inverted waveforms. We suggest that the polarity of the HRF is a separate factor that is independent of the suppressive or activating nature of the underlying neuronal activity. Correctly modeling the polarity of the HRF allows one to recover an estimate of the underlying neuronal activity rather than discard the responses from these voxels on the assumption that they are artifactual. We demonstrate this approach on phase‐encoded retinotopic mapping data as an example of the benefits of accurately modeling the HRF during the analysis of fMRI data. Hum Brain Mapp 35:5550–5564, 2014. © 2014 Wiley Periodicals, Inc.
An ALE meta‐analysis on the audiovisual integration of speech signals
Authors: Erickson Laura C. , Heeg Elizabeth , Rauschecker Josef P. , Turkeltaub Peter E. 
Published: July 2014

AbstractThe brain improves speech processing through the integration of audiovisual (AV) signals. Situations involving AV speech integration may be crudely dichotomized into those where auditory and visual inputs contain (1) equivalent, complementary signals (validating AV speech) or (2) inconsistent, different signals (conflicting AV speech). This simple framework may allow the systematic examination of broad commonalities and differences between AV neural processes engaged by various experimental paradigms frequently used to study AV speech integration. We conducted an activation likelihood estimation metaanalysis of 22 functional imaging studies comprising 33 experiments, 311 subjects, and 347 foci examining “conflicting” versus “validating” AV speech. Experimental paradigms included content congruency, timing synchrony, and perceptual measures, such as the McGurk effect or synchrony judgments, across AV speech stimulus types (sublexical to sentence). Colocalization of conflicting AV speech experiments revealed consistency across at least two contrast types (e.g., synchrony and congruency) in a network of dorsal stream regions in the frontal, parietal, and temporal lobes. There was consistency across all contrast types (synchrony, congruency, and percept) in the bilateral posterior superior/middle temporal cortex. Although fewer studies were available, validating AV speech experiments were localized to other regions, such as ventral stream visual areas in the occipital and inferior temporal cortex. These results suggest that while equivalent, complementary AV speech signals may evoke activity in regions related to the corroboration of sensory input, conflicting AV speech signals recruit widespread dorsal stream areas likely involved in the resolution of conflicting sensory signals. Hum Brain Mapp 35:5587–5605, 2014. © 2014 Wiley Periodicals, Inc.
Outcomes of nodal metastatic cutaneous squamous cell carcinoma of the head and neck treated in a regional center
Authors: Schmidt Campbell , Martin Jarad M. , Khoo Eric , Plank Ashley , Grigg Roger 
Published: July 2014

ABSTRACTBackgroundGiven its metastatic potential and high incidence, cutaneous squamous cell carcinoma of the head and neck (SCCHN) has significant morbidity and mortality.MethodsWe conducted a retrospective review of prospectively collected data for 113 consecutive patients with nodal metastatic cutaneous SCCHN treated surgically with curative intent in a regional center. Survival curves were generated by the Kaplan–Meier method.ResultsFive‐year overall survival (OS), disease‐specific survival (DSS), and disease‐free survival (DFS) were 80%, 83%, and 75%, respectively. Twenty‐six patients (23%) relapsed, with 92% of relapses occurring within 2 years of surgery. Immunosuppression (p = .008) and N classification (p = .043) predicted decreased DFS on univariate analysis. On multivariate analysis, only immunosuppression independently predicted DFS (p = .034).ConclusionThis study validates the current N classification system, supports the adverse effect of immunosuppression, and suggests that intense follow‐up for 2 years postsurgery is warranted. Survival at this regional center is comparable to that achieved at metropolitan tertiary cancer centers. © 2015 Wiley Periodicals, Inc. Head Neck 37: 1808–1815, 2015
Computational complexity of finding Pareto efficient outcomes for biobjective lot‐sizing models
Authors: Romeijn H. Edwin , Morales Dolores Romero , Van den Heuvel Wilco 
Published: July 2014

AbstractIn this article, we study a biobjective economic lot‐sizing problem with applications, among others, in green logistics. The first objective aims to minimize the total lot‐sizing costs including production and inventory holding costs, whereas the second one minimizes the maximum production and inventory block expenditure. We derive (almost) tight complexity results for the Pareto efficient outcome problem under nonspeculative lot‐sizing costs. First, we identify nontrivial problem classes for which this problem is polynomially solvable. Second, if we relax any of the parameter assumptions, we show that (except for one case) finding a single Pareto efficient outcome is an ‐hard task in general. Finally, we shed some light on the task of describing the Pareto frontier. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 386–402, 2014
Unified analysis of preconditioning methods for saddle point matrices
Authors: Axelsson Owe 
Published: July 2014

SummaryShort and unified proofs of spectral properties of major preconditioners for saddle point problems are presented. The need to sufficiently accurately construct approximations of the pivot block and Schur complement matrices to obtain real eigenvalues or eigenvalues with positive real parts and non‐dominating imaginary parts are pointed out. The use of augmented Lagrangian methods for more ill‐conditioned problems are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Thrombosis of torcular herophili: diagnosis, prenatal management, and outcome
Authors: Rayssiguier Romy , Dumont Coralie , Flunker Sabrina , Couture Alain , Boulot Pierre , Prodhomme Olivier 
Published: July 2014

ABSTRACTObjectivesThe objective of this article is to describe and assess prenatal imaging findings, fetal and postnatal outcomes of thrombosis of torcular herophili, and to determine diagnostic features, pathophysiology, prognosis, and optimal management.MethodsOver a decade, we compiled the largest single‐center retrospective study of outcomes. Fetal magnetic resonance imaging (MRI) was used to confirm the sonographic suspicion and monitor thrombosis of torcular herophili. We noted prenatal and postnatal imaging specifications, pregnancy outcomes, and clinical and radiological pediatric monitoring. Analysis of findings and review of the literature allowed us to define prognostic factors.ResultsIn eight cases of prenatal diagnosis of thrombosis of torcular herophili, MRI outcomes were specific. There were five deliveries at full term, two terminations of pregnancy, and one fetal demise in utero. Neonates had a good clinical and radiological outcome. Factors of poor prognosis were deep venous sinus thrombosis, enduring mass effect, brain parenchymal injury, and heart failure related to dural arteriovenous shunt.ConclusionAmong dural sinus malformations, thrombosis of torcular herophili with or without extension at the posterior segment of the longitudinal sinus frequently has a good prognosis. It is urgent to wait because the prognosis can only be ascertained over time by means of ultrasound scan and MRI monitoring. © 2014 John Wiley & Sons, Ltd.
Sonographic diagnosis of ectopia cordis before 9 weeks of gestation
Authors: Sepulveda Waldo , Andreeva Elena , Machado Luiz E. 
Published: July 2014

What's already known about this topic?Ectopia cordis is a rare, almost invariably lethal, condition that can be readily diagnosed by prenatal sonography.The prenatal diagnosis of ectopia cordis before 9 weeks has not been reported.What does this study add?This series of three cases documents, the earliest diagnosis of ectopia cordis reported to date.Ectopia cordis seems to be associated with a high lethality rate in early embryos, suggesting that this condition could be more frequent than previously reported.
Hydrophobically modified polyelectrolyte for improved oxygen barrier in nanobrick wall multilayer thin films
Authors: Stevens Bart E. , Odenborg Patrick K. , Priolo Morgan A. , Grunlan Jaime C. 
Published: July 2014

ABSTRACTThe influence of attaching hydrophobic side groups to a polyelectrolyte, used for deposition of a multilayer oxygen gas barrier thin film, was investigated. Polyethyleneimine (PEI) was labeled with pyrene and deposited in “quadlayers” of PEI, poly(acrylic acid), PEI, and sodium montmorillonite clay using layer‐by‐layer assembly. Thin films made of three repeating quadlayers using unmodified PEI had much lower density (1.24 g/cm3) than pyrene‐labeled PEI‐based films (1.45 g/cm3), which is believed to be the result of greater chain coiling from the increased hydrophobicity of pendant pyrene groups. This increased density in pyrene‐labeled PEI layers allowed three quadlayers to match the oxygen transmission rate of a four quadlayer film made with unmodified PEI. This discovery provides an additional tool for tailoring the barrier behavior of clay‐based multilayer thin films that could prove useful for a variety of packaging applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1153–1156
Noncommutative quantum field theory
Authors: Grosse H. , Wulkenhaar R. 
Published: July 2014

AbstractWe summarize our recent construction of the ϕ4‐model on four‐dimensional Moyal space. This is achieved by solving the quartic matrix model for a general external matrix in terms of the solution of a non‐linear equation for the 2‐point function and the eigenvalues of that matrix. The β‐function vanishes identically. For the Moyal model, the theory of Carleman type singular integral equations reduces the construction to a fixed point problem. The resulting Schwinger functions in position space are symmetric and invariant under the full Euclidean group. The Schwinger 2‐point function is reflection positive iff the diagonal matrix 2‐point function is a Stieltjes function.
Complex geometry of quantum cones
Authors: Brzeziński T. 
Published: July 2014

AbstractThe algebras obtained as fixed points of the action of the cyclic group ℤN on the coordinate algebra of the quantum disc are studied. These can be understood as coordinate algebras of quantum or non‐commutative cones. The following observations are made. First, contrary to the classical situation, the actions of ℤN are free and the resulting algebras are homologically smooth. Second, the quantum cone algebras admit differential calculi that have all the characteristics of calculi on smooth complex curves. Third, the corresponding volume forms are exact, indicating that the constructed algebras describe manifolds with boundaries.
Regulation of prostaglandin EP1 and EP4 receptor signaling by carrier‐mediated ligand reuptake
Authors: Chi Yuling , Suadicani Sylvia O. , Schuster Victor L. 
Published: July 2014

AbstractAfter synthesis and release from cells, prostaglandin E2 (PGE2) undergoes reuptake by the prostaglandin transporter (PGT), followed by cytoplasmic oxidation. Although genetic inactivation of PGT in mice and humans results in distinctive phenotypes, and although experiments in localized environments show that manipulating PGT alters downstream cellular events, a direct mechanistic link between PGT activity and PGE2 (EP) receptor activation has not been made. Toward this end, we created two reconstituted systems to examine the effect of PGT expression on PGE2 signaling via two of its receptors (EP1 and EP4). In human embryonic kidney cells engineered to express the EP1 receptor, exogenous PGE2 induced a dose‐dependent increase in cytoplasmic Ca2+. When PGT was expressed at the plasma membrane, the PGE2 dose–response curve was right‐shifted, consistent with reduction in cell surface PGE2 availability; a potent PGT inhibitor acutely reversed this shift. When bradykinin was used to induce endogenous PGE2 release, PGT expression similarly induced a reduction in Ca2+ responses. In separate experiments using Madin–Darby Canine Kidney cells engineered to express the PGE2 receptor EP4, bradykinin again induced autocrine PGE2 signaling, as judged by an abrupt increase in intracellular cAMP. As in the EP1 experiments, expression of PGT at the plasma membrane caused a reduction in bradykinin‐induced cAMP accumulation. Pharmacological concentrations of exogenous PGE2 induced EP4 receptor desensitization, an effect that was mitigated by PGT. Thus, at an autocrine/paracrine level, plasma membrane PGT regulates PGE2 signaling by decreasing ligand availability at cell surface receptors.
Impact of DDT on FPSO explosion risk assessment
Authors: Hansen Olav Roald , Martini Remi , Choi Jaewoong , Ryu Yonghee 
Published: July 2014

In recent explosion accidents on onshore petrochemical facilities, it has been concluded that a deflagration‐to‐detonation‐transition (DDT) took place, both with Liquefied Petroleum Gas (LPG) and gasoline vapor. DDT has also been observed in a number of large‐scale experiments. DDT leads to very high pressures (16–20 barg) and flame speeds (1,600–2,000 m/s) even outside congested regions and has a significant impact on the severity of the near‐field and far‐field explosion loads. It has not been generally accepted that DDT may be a threat at offshore petrochemical facilities and prediction tools have not been available. Thus, the potential effect of DDT is seldom considered. For Floating production, storage and offloading vessels (FPSOs), and even more Floating liquified natural gas vessels (FLNGs), due to larger dimensions and inventories, operators should be concerned that major explosion scenarios can lead to DDT phenomena.Recently, a DDT prediction parameter was implemented in the Computational Fluid Dynamics (CFD) model FLACS, and with model adjustments it is possible to calculate DDT and effect on explosion loads with good precision. A CFD‐based FPSO explosion study is presented evaluating DDT potential and impact. DDT will mainly be a concern for large cloud sizes, often larger than commonly considered for design accidental loads for an FPSO (10−4/year). Mitigation by separation walls is also evaluated. © 2014 American Institute of Chemical Engineers Process Saf Prog 34: 44–57, 2015
PoliCon: a policy conciliation framework for heterogeneous mobile ad hoc networks
Authors: Maity Soumya , Ghosh Soumya K. , Al‐Shaer Ehab 
Published: July 2014

AbstractIt is increasingly important to implement a conflict‐free access control policies for co‐allied networks where different organizations are involve for a common goal. Mobile ad hoc networks are widely used for mission critical situations where teams from different organizational networks cooperate to form a single network to implement their respective operations. These teams (or quads) have different sets of local policies enforced for their own security resulting heterogeneity in access control. Each team wants to preserve its access control policies at a maximum level. Moreover, a set of allied policies govern the cooperation and interaction between the different teams, which may conflict with their local policies. The policy conflicts arise from the transitivity of policy rules, mobility of the nodes, cooperative behaviors, and so on. In addition, the policy rules may be temporal or static. To achieve the successful completion of the mission, it may be required to compromise with the stringency of the enforcement of the conflicting rules for the quads. In this paper, we propose an automated and formal framework to find the optimal conciliation of the policy rules to preserve the mission and thus ensure minimal compromise with the enforcement of policy for each quad. The efficacy of the work lies on optimizing the enforcement of access control policies to achieve the coalition instead of negating the policy. Copyright © 2014 John Wiley & Sons, Ltd.