bluuebunny/crossref_metadata_2025 huggingface dataset:
Sulfur‐Doped Carbons Prepared from Eutectic Mixtures Containing Hydroxymethylthiophene as Metal‐Free Oxygen Reduction Catalysts
Authors: López‐Salas Nieves , del Monte Francisco , Tamayo Aitana , Fierro José Luís G. , De Lacey Antonio L. , Ferrer M. Luisa , Gutiérrez María C.
Published: October 2014

A template‐free approach based on the use of eutectic mixtures composed of 2‐hydroxymethylthiophene and furfuryl alcohol has been designed for the preparation of hierarchical sulfur‐doped carbons (SPCs) in monolithic form. The temperature used for carbonization, for example, 600, 800, or 900 °C, determined most of the physicochemical properties of the resulting SPCs. Thus, the surface area increased from below 400 to up 775 m2 g−1, along with the carbonization temperature, whereas the sulfur content decreased from approximately 15 to 5 wt %. The oxygen reduction reaction performance in samples carbonized at 900 °C was good, with the four‐electron‐transfer reaction prevailing over the two‐electron‐transfer one. Interestingly, the methanol tolerance and stability of these SPCs were also remarkable, with less than 5 % current decrease immediately after methanol addition, whereas, in terms of stability, the current decrease was below 8 % after 20000 s. This performance was in the range of that found not only for other SPCs, but also for many nitrogen‐doped and even some dual‐doped (S and N) ones.
Automating the sizing of transistors in CMOS gates for low‐power and high‐noise margin operation
Authors: Beg Azam
Published: October 2014

This paper presents an automatic method for sizing the transistors in CMOS gates. The method utilizes a feedback control system to efficiently optimize the transistor sizes in small and large fan‐in gates, with the primary goal of enhancing noise robustness (as characterized by the static noise margin). The gates retain their robustness under threshold‐voltage variations over a range of supply voltages. The optimized gates not only expend reduced power and energy, but also take up less area than the conventional ones. These multi‐faceted gains, however, do incur some performance loss. Copyright © 2014 John Wiley & Sons, Ltd.
Conflicting consequences of immunity to cancer versus autoimmunity to neurons: Insights from paraneoplastic disease
Authors: Steinman Lawrence
Published: October 2014

Immunologists are well aware that cancer regression and increased patient survival with the use of checkpoint inhibitors, such as ipilimumab, an antibody directed against cytotoxic T‐lymphocyte–associated antigen 4, CTLA‐4 (CD152), is accompanied by concomitant autoimmunity. For over 30 years, a small group of investigators have shown that the rare paraneoplastic syndromes are caused by immunity to shared antigens found on both tumors and on components of the nervous system. In this issue of the European Journal of Immunology, Blachère et al. [Eur. J. Immunol. 2014. 44: 3240–3251] elucidate some of the molecular mechanisms underlying the tolerance to neuronal antigens which share epitopes with oncologic antigens, observed in the context of paraneoplastic syndromes in mice. The presence of the shared tumor antigen on a nonhematopoietic cell underlies the basis for a certain level of tolerance in CD4+ and CD8+ T cells, preventing these cells from attacking the brain, but allowing them to lyse the tumor upon transfer into tumor‐bearing recipient mice. Comparisons between the paraneoplastic syndromes and the new autoimmune conditions seen with antibodies to immune checkpoints at CD152 or at CD279 are likely to illuminate shared mechanisms and solutions to these vexing diseases.
Optokinetic stimulation increases limb pain and forehead hyperalgesia in complex regional pain syndrome
Authors: Knudsen L.F. , Drummond P.D.
Published: October 2014

Background

Ambiguous visual stimuli increase limb pain in patients with complex regional pain syndrome (CRPS), possibly due to afferent sensory feedback conflicts. Conflicting sensory stimuli can also generate unpleasant sensations in healthy people such as during motion sickness. We wanted to investigate the mechanisms underlying the link between sensory conflicts and pain in CRPS using optokinetic stimulation (OKS) – a method known to induce motion sickness.

Methods

Twenty‐one CRPS patients underwent OKS and rated symptoms of motion sickness. Patients also rated limb pain and pain‐related distress before, during and after OKS. In addition, pressure‐pain and sharpness sensations were investigated on both sides of the forehead and in the affected and contralateral limb before and after OKS.

Results

Limb pain and forehead hyperalgesia to pressure increased in parallel in response to OKS. In a subgroup of nauseated patients who withdrew early from OKS, hyperalgesia to pressure in the ipsilateral forehead persisted longer than in the remaining participants. Sharpness sensations remained constant at all sites.

Conclusions

Sensory conflicts may facilitate pain in CRPS by activating the mechanisms of general facilitation of nociception and, during more severe sensory conflicts, also a facilitatory mechanism that operates mainly ipsilateral to the affected limb.
Electrochemiluminescence Sensor for Phosphate Ions Based on Europium(III)‐Modulated CdSe Quantum Dots
Authors: Li Qi‐Le , Bao Ning , Ding Shou‐Nian
Published: October 2014

Phosphate anions are determined based on the electrochemiluminescence (ECL) of CdSe quantum dots (CdSe QDs) capped with 3‐mercaptopropionic acid. The ECL gets quenched with the introduction of Eu3+ ions, but it is restored on the further addition of phosphate anions. The sensing mechanism might be due to the strong and specific interaction between phosphate anions and the Eu3+ ions, leading to the releasing of CdSe QDs from aggregates. On the basis of the quenching/recovery ECL behaviors, the ECL sensor offer acceptable sensitivity, high selectivity, and a linear response from 0.1 to 120 µM with a detection limit of 0.03 µM (3δ) for phosphate anions.
Simple DPPH.‐Based Electrochemical Assay for the Evaluation of the Antioxidant Capacity: a Thorough Comparison with Spectrophotometric Assays and Evaluation with Real‐World Samples
Authors: Andrei Veronica , Bunea Ada‐Ioana , Tudorache Aurelia , Gáspár Szilveszter , Vasilescu Alina
Published: October 2014

An assay based on the electrochemical detection of 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH.) for the evaluation of the total antioxidant capacity (TAC) was optimized. The assay is interchangeable with the classic spectrophotometric tests for TAC based on the same radical. In addition, it can be used for the analysis of dilute samples with low antioxidant capacities. A good linear correlation (R2=0.97) was obtained between the results obtained with the proposed electrochemical assay and the Trolox Equivalent Antioxidant Capacity test based on ABTS radical. The assay was successfully used to evaluate the antioxidant capacity of two red wines obtained by six different maceration‐fermentation techniques.
A Simple Econometric Approach for Modeling Stress Event Intensities
Authors: Jobst Rainer , Rösch Daniel , Scheule Harald , Schmelzle Martin
Published: October 2014

This paper introduces a simple, non‐parametric way of inferring risk‐neutral credit stress event intensities for idiosyncratic, sectoral, and global shocks contained in market credit spreads. We provide an econometric analysis of the implied latent stress event dynamics. A vector autoregressive regression model with exogenous variables finds that these intensities can be related to an observable stock market index, the market volatility, the volatility skew, and treasury yields. © 2014 Wiley Periodicals, Inc. Jrl Fut Mark 35:300–320, 2015
Validation of the Montreal Cognitive Assessment (MoCA) in Spanish as a screening tool for mild cognitive impairment and mild dementia in patients over 65 years old in Bogotá, Colombia
Authors: Gil Laura , Ruiz de Sánchez Carolina , Gil Fabián , Romero Sara Julieta , Pretelt Burgos Felipe
Published: October 2014

Objective

The Montreal Cognitive Assessment (MoCA) was developed as a simple screening tool for cognitive impairment. This study is the first validation in Latin America of the MoCA in Spanish (MoCA‐S), which was developed in Colombia (South America).

Methods

Aiming to perform the first validation of the MoCA‐S, we developed a study of concordance by conformity to assess the MoCA‐S compared with diagnostic consensus by interdisciplinary assessment in the Memory Clinic (the best diagnostic method available) and to evaluate the psychometric properties of the MoCA‐S. A total of 193 subjects were evaluated, 109 of whom were patients, including 26 who met the mild cognitive impairment (MCI) clinical criteria, based on neuropsychological testing, and 83 who had mild dementia (MD). The remaining 84 participants were healthy subjects from the community.

Results

The psychometric evaluation of the MoCA‐S was appropriate. Using a cutoff score of ≥23, the MoCA had sensitivities of 76.0% to detect MCI and 92.7% to detect MD and a specificity of 79.8%. The percentage of patients clearly labeled by the MoCA‐S was 85%.

Conclusion

The MoCA‐S is a valid screening tool and is useful for identifying MCI and MD in Colombia. The MoCA‐S is valid and adequate for application in Colombia with good internal consistency, inter‐observer reliability, and content validity. However, the average educational level was high in this study; thus, caution should be exercised when extrapolating these results to individuals with lower educational levels. Copyright © 2014 John Wiley & Sons, Ltd.
Brain activation to briefly presented emotional words: Effects of stimulus awareness
Authors: Hoffmann Marius , Mothes‐Lasch Martin , Miltner Wolfgang H.R. , Straube Thomas
Published: October 2014

It is unknown to what extent briefly presented emotional words can be processed without awareness. By means of two independent functional magnetic resonance imaging studies, using either a block or an event‐related design, we investigated brain activation to very briefly presented threat related and neutral words during two backward masking conditions (with and without gap between target and mask). In both experiments, emotional words were perceived during the supraliminal “with gap” condition, but they were not recognized during the subliminal “without gap” condition, as indicated by signal detection theory analysis. Imaging results of both experiments showed increased activation of the amygdala, the medial prefrontal cortex and language‐processing cortical areas to negative versus neutral words during supraliminal but not subliminal conditions. These results suggest that even very briefly presented emotional words are capable of triggering increased cortical and subcortical processing; however, only when awareness of these stimuli is given. Hum Brain Mapp 36:655–665, 2015. © 2014 Wiley Periodicals, Inc.
Acute effect of glucose on cerebral blood flow, blood oxygenation, and oxidative metabolism
Authors: Xu Feng , Liu Peiying , Pascual Juan M , Xiao Guanghua , Huang Hao , Lu Hanzhang
Published: October 2014

While it is known that specific nuclei of the brain, for example hypothalamus, contain glucose‐sensing neurons thus their activity is affected by blood glucose level, the effect of glucose modulation on whole‐brain metabolism is not completely understood. Several recent reports have elucidated the long‐term impact of caloric restriction on the brain, showing that animals under caloric restriction had enhanced rate of tricarboxylic acid cycle (TCA) cycle flux accompanied by extended life span. However, acute effect of postprandial blood glucose increase has not been addressed in detail, partly due to a scarcity and complexity of measurement techniques. In this study, using a recently developed noninvasive MR technique, we measured dynamic changes in global cerebral metabolic rate of O2 (CMRO2) following a 50 g glucose ingestion (N = 10). A time dependent decrease in CMRO2 was observed, which was accompanied by a reduction in oxygen extraction fraction (OEF) with unaltered cerebral blood flow (CBF). At 40 min post‐ingestion, the amount of CMRO2 reduction was 7.8 ± 1.6%. A control study without glucose ingestion was performed (N = 10), which revealed no changes in CMRO2, CBF, or OEF, suggesting that the observations in the glucose study was not due to subject drowsiness or fatigue after staying inside the scanner. These findings suggest that ingestion of glucose may alter the rate of cerebral metabolism of oxygen in an acute setting. Hum Brain Mapp 36:707–716, 2015. © 2014 Wiley Periodicals, Inc.
Uncertainty during pain anticipation: The adaptive value of preparatory processes
Authors: Seidel Eva‐Maria , Pfabigan Daniela M. , Hahn Andreas , Sladky Ronald , Grahl Arvina , Paul Katharina , Kraus Christoph , Küblböck Martin , Kranz Georg S. , Hummer Allan , Lanzenberger Rupert , Windischberger Christian , Lamm Claus
Published: October 2014

Objectives: Anticipatory processes prepare the organism for upcoming experiences. The aim of this study was to investigate neural responses related to anticipation and processing of painful stimuli occurring with different levels of uncertainty. Experimental design: Twenty‐five participants (13 females) took part in an electroencephalography and functional magnetic resonance imaging (fMRI) experiment at separate times. A visual cue announced the occurrence of an electrical painful or nonpainful stimulus, delivered with certainty or uncertainty (50% chance), at some point during the following 15 s. Principal observations: During the first 2 s of the anticipation phase, a strong effect of uncertainty was reflected in a pronounced frontal stimulus‐preceding negativity (SPN) and increased fMRI activation in higher visual processing areas. In the last 2 s before stimulus delivery, we observed stimulus‐specific preparatory processes indicated by a centroparietal SPN and posterior insula activation that was most pronounced for the certain pain condition. Uncertain anticipation was associated with attentional control processes. During stimulation, the results revealed that unexpected painful stimuli produced the strongest activation in the affective pain processing network and a more pronounced offset‐P2. Conclusions: Our results reflect that during early anticipation uncertainty is strongly associated with affective mechanisms and seems to be a more salient event compared to certain anticipation. During the last 2 s before stimulation, attentional control mechanisms are initiated related to the increased salience of uncertainty. Furthermore, stimulus‐specific preparatory mechanisms during certain anticipation also shaped the response to stimulation, underlining the adaptive value of stimulus‐targeted preparatory activity which is less likely when facing an uncertain event. Hum Brain Mapp 36:744–755, 2015. © 2014 Wiley Periodicals, Inc.
Colorimetric detection of in situ metal acetates and fluorides by a bipyridyl‐linked Schiff base
Authors: Suganya Sivalingam , Zo Hye Jin , Park Jong S. , Velmathi Sivan
Published: October 2014

Here, we present a new bipyridyl moiety linked Schiff base (bipy‐1) that is well characterized using spectroscopic techniques. Colorimetric and UV‐vis titrations were used to study the photophysical properties of bipy‐1 in the presence of various tetrabutyl ammonium salt of anions and metal salts containing different counter cations. bipy‐1 showed selective recognition of dimethyl sulphoxide solution of tetrabutyl ammonium salt of F− ion accompanied with a UV‐vis band at 529 nm and interesting binding of aqueous Co, Ni, and Cu acetates/fluorides, as confirmed by distinct color changes from fluorescent green to pink or orange and a strong band around 480–510 nm in the UV‐vis spectrum. However, in the presence of Co, Ni, and Cu countercations, any form of metal acetate/fluorides was found to be able to respond to similar color changes from fluorescent green to pink or orange, showing a band around 480–510 nm. This type of output clearly indicates that the in situ formation of Co, Ni, and Cu acetates/fluorides also coordinates with bipyridyl nitrogen atoms. Copyright © 2014 John Wiley & Sons, Ltd.
Characterization of a new maleimido functionalization of gold for surface plasmon resonance spectroscopy
Authors: Hovestädt Marc , Memczak Henry , Pleiner Dennis , Zhang Xin , Rappich Jörg , Bier Frank F. , Stöcklein Walter F. M.
Published: October 2014

Para‐maleimidophenyl (p‐MP) modified gold surfaces have been prepared by one‐step electrochemical deposition and used in surface plasmon resonance (SPR) studies. Therefore, a FITC mimotope peptide (MP1, 12 aa), a human mucin 1 epitope peptide (MUC, 9 aa) and a protein with their specific antibodies were used as model systems. The peptides were modified with an N‐terminal cysteine for covalent and directed coupling to the maleimido functionalized surface by means of Michael addition. The coupling yield of the peptide, the binding characteristics of antibody and the unspecific adsorption of the analytes were investigated. The results expand the spectrum of biosensors usable with p‐MP by widely used SPR and support its potential to be versatile for several electrochemical and optical biosensors. This allows the combination of an electrochemical and optical read‐out for a broad variety of biomolecular interactions on the same chip. Copyright © 2014 John Wiley & Sons, Ltd.
Zinc(II) complexation by some biologically relevant pH buffers
Authors: Wyrzykowski D. , Tesmar A. , Jacewicz D. , Pranczk J. , Chmurzyński L.
Published: October 2014

The isothermal titration calorimetry (ITC) technique supported by potentiometric titration data was used to study the interaction of zinc ions with pH buffer substances, namely 2‐(N‐morpholino)ethanesulfonic acid (Mes), piperazine‐N,N′‐bis(2‐ethanesulfonic acid) (Pipes), and dimethylarsenic acid (Caco). The displacement ITC titration method with nitrilotriacetic acid as a strong, competitive ligand was applied to determine conditional–independent thermodynamic parameters for the binding of Zn(II) to Mes, Pipes, and Caco. Furthermore, the relationship between the proposed coordination mode of the buffers and the binding enthalpy has been discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Screening and characterization of anti‐SEB peptides using a bacterial display library and microfluidic magnetic sorting
Authors: Kogot Joshua M. , Pennington Joseph M. , Sarkes Deborah A. , Kingery David A. , Pellegrino Paul M. , Stratis‐Cullum Dimitra N.
Published: October 2014

Bacterial peptide display libraries enable the rapid and efficient selection of peptides that have high affinity and selectivity toward their targets. Using a 15‐mer random library on the outer surface of Escherichia coli (E.coli), high‐affinity peptides were selected against a staphylococcal enterotoxin B (SEB) protein after four rounds of biopanning. On‐cell screening analysis of affinity and specificity were measured by flow cytometry and directly compared to the synthetic peptide, off‐cell, using peptide‐ELISA. DNA sequencing of the positive clones after four rounds of microfluidic magnetic sorting (MMS) revealed a common consensus sequence of (S/T)CH(Y/F)W for the SEB‐binding peptides R338, R418, and R445. The consensus sequence in these bacterial display peptides has similar amino acid characteristics with SEB peptide sequences isolated from phage display. The Kd measured by peptide‐ELISA off‐cell was 2.4 nM for R418 and 3.0 nM for R445. The bacterial peptide display methodology using the semiautomated MMS resulted in the discovery of selective peptides with affinity for a food safety and defense threat. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Journal of Molecular Recognition published by John Wiley & Sons, Ltd.
RF modeling of 40‐nm SOI triple‐gate FinFET
Authors: Martinez‐Lopez A. G. , Cerdeira A. , Tinoco J. C. , Alvarado J. , Padron W. Y. , Mendoza C. , Raskin J.‐P.
Published: October 2014

These last years, the triple‐gate fin field‐effect transistor (FinFET) has appeared as attractive candidate to pursue the complementary metal‐oxide semiconductor technology roadmap for digital and analog applications. However, the development of analog applications requires models that properly describe the static and RF behaviors as well as the extrinsic parameters related to the three‐dimensional FinFET architecture, in order to establish adequate design strategies. We demonstrate the feasibility of the compact model developed for symmetric doped double‐gate metal‐oxide‐semiconductor field‐effect transistor (symmetric doped double‐gate MOSFET) to reproduce the experimental dc and RF behaviors for 40‐nm technology node Silicon‐on‐Insulator triple‐gate FinFETs. Extrinsic gate capacitances and access extrinsic resistances have been included in order to properly predict the transistor small‐signal behavior, the current gain, and the maximum available power gain cut‐off frequencies. Finally, the improvement of the FinFET RF characteristics by the reduction of the parasitics is addressed. Copyright © 2014 John Wiley & Sons, Ltd.
The Impact of Childhood Abuse Among Women With Assault‐Related PTSD Receiving Short‐Term Cognitive–Behavioral Therapy
Authors: Resick Patricia A. , Suvak Michael K. , Wells Stephanie Y.
Published: October 2014

This study examined the effect of child sexual or physical abuse on brief cognitive–behavioral therapy treatments with adults with posttraumatic stress disorder (PTSD). We analyzed secondary data from two randomized controlled trials (Resick, Nishith, Weaver, Astin, & Feuer, 2002; Resick et al., 2008) that included women with PTSD who did or did not have child sexual abuse (CSA) or child physical abuse (CPA) histories to determine whether childhood abuse impacted dropout rate or reduction in PTSD symptoms. In Study 1, presence, duration, or severity of CSA was not associated with dropout; however, frequency of CSA significantly predicted dropout (OR = 1.23). A significant CPA Severity × Treatment Group interaction emerged such that CPA severity was associated with greater dropout for prolonged exposure (PE; OR = 1.45), but not cognitive processing therapy (CPT; OR = 0.90). Study 2 found no differences in dropout. Study 1, comparing CPT and PE among women who experienced at least 1 rape found no differences in outcome based on childhood abuse history (rp2s = .000–.009). Study 2, a dismantling study of CPT with women seeking treatment for adult or child sexual or physical abuse found that for those with no childhood abuse, CPT‐C, the cognitive‐only version of CPT, had an advantage, whereas both forms of CPT worked best for those with higher frequency of childhood abuse; the effect size was small.
Probable Posttraumatic Stress Disorder and Women's Use of Aggression in Intimate Relationships: The Moderating Role of Alcohol Dependence
Authors: Weiss Nicole H. , Duke Aaron A. , Sullivan Tami P.
Published: October 2014

Posttraumatic stress disorder (PTSD) is highly prevalent among individuals who experience intimate partner violence (IPV) and is associated with aggression in intimate relationships. The present study examined whether alcohol dependence (AD) attenuates the relation between PTSD and IPV‐victimized women's use of physical, psychological, and sexual aggression. Participants were recruited from the community and included 147 women who engaged in substance use and experienced IPV (80.3% Black; M age = 38.24 years, SD = 10.62; M income = $14,323, SD = $12,832). Women with (vs. without) AD reported using significantly more physical and psychological aggression (ηp2 = .12 and .03, respectively). The probable PTSD × AD interaction emerged as a significant correlate of physical and sexual aggression (ηp2 = .03). Post hoc analyses revealed higher levels of physical aggression among women with probable PTSD and AD and no‐PTSD and AD compared to women with probable PTSD and no‐AD (Cohen's ds = 1.09 and 0.63, respectively) and women without PTSD and no‐AD (Cohen's ds = 0.92 and 0.60, respectively). Further, women with PTSD and AD reported higher levels of sexual aggression than women without PTSD and AD (Cohen's d = 0.80). Findings suggest the utility of identifying and treating PTSD‐AD among IPV‐victimized women.
Glutathione‐Responsive DNA‐Based Nanocontainers Through an “Interfacial Click” Reaction in Inverse Miniemulsion
Authors: Paiphansiri Umaporn , Baier Grit , Kreyes Andreas , Yiamsawas Doungporn , Koynov Kaloian , Musyanovych Anna , Landfester Katharina
Published: October 2014

The synthesis of nanoscale biocompatible carriers that are able to release encapsulated material within an intracellular environment in a controlled way still remains a challenge. Hereby, the synthesis of a new class of DNA‐based nanocontainers having a glutathione‐cleavable shell is described. These containers are able to break in response to the presence of intracellular specific tripeptide glutathione in the surrounding medium. The formulation of nanocontainers in the size range between 190 and 220 nm is achieved through the interfacial thiol–disulfide exchange reaction between dithiol DNA oligonucleotides (20 bases) and disulfide groups of a comonomer in inverse miniemulsion. DNA containers with different disulfide moieties are synthesized by taking different ratios of a dimaleimide‐based fluorescent BODIPY dye and the disulfide monomer, which form the shell through the “interfacial click” of the thiol‐ene reaction and the dithiol exchange reaction of the glutathione‐cleavable disulphide comonomer. The disruption kinetics of the shell upon addition of glutathione into the dispersion are investigated by isothermal titration calorimetry (ITC). Cleavage of the nanocontainer's shell containing fluorescent BODIPY dye is confirmed by fluorescence correlation spectroscopy (FCS). It is believed that the obtained nanocontainers have great potential as smart nanocarriers in biosensor and therapeutic applications.

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Stone porosity, wettability changes and other features detected by MRI and NMR relaxometry: a more than 15‐year study
Authors: Camaiti Mara , Bortolotti Villiam , Fantazzini Paola
Published: October 2014

Scientists applying magnetic resonance techniques to cultural heritage are now a quite vast and international community, even if these applications are not yet well known outside this community. Not only laboratory experiments but also measurements in the field are now possible, with the use of portable nuclear magnetic resonance (NMR) instruments that enable non‐invasive and non‐destructive studies on items of any size, of high artistic and historical value as well as diagnosis of their conservation state. The situation was completely different in the second half of the 1990s when our group started working on applications of NMR to cultural heritage, by combining the knowledge of NMR for fluids in porous media at the University of Bologna, with the skilfulness of the chemists for cultural heritage of CNR and University of Florence, and Safeguarding Cultural Heritage Department of Aosta. Since then, our interest has been mainly devoted to develop methods to study the structure of pore space and their changes as a result of the decay, as well as to evaluate performance of the protective and conservative treatments of porous materials like stone, ceramic, cements and wood. In this paper, we will review the pathway that led us from the first tentative experiments, in the second half of the 1990s to the current work on these topics. Copyright © 2014 John Wiley & Sons, Ltd.
Inhomogeneous static magnetic field‐induced distortion correction applied to diffusion weighted MRI of the breast at 3T
Authors: Teruel Jose R. , Fjøsne Hans E. , Østlie Agnes , Holland Dominic , Dale Anders M. , Bathen Tone F. , Goa Pål E.
Published: October 2014

Purpose

To evaluate the performance of an advanced method for correction of inhomogeneous static magnetic field induced distortion in echo‐planar imaging (EPI), applied to diffusion‐weighted MRI (DWI) of the breast.

Methods

An algorithm for distortion correction based on the symmetry of the distortion induced by static field inhomogeneity when the phase encoding polarity is reversed was evaluated in 36 data sets of patients who received an MRI examination that included DWI (b = 0 and 700 s/mm2) and an extra b = 0 s/mm2 sequence with opposite phase encoding polarity. The decrease of the L2‐square norm after correction between opposed phase encoding b = 0 images was calculated. Mattes mutual information between b = 0 images and fat‐suppressed T2‐weighted images was calculated before and after correction.

Results

The L2‐square norm between different phase encoding polarities for b = 0 images was reduced 94.3% on average after distortion correction. Furthermore, Mattes mutual information between b = 0 images and fat‐suppressed T2‐weighted images increased significantly after correction for all cases (P < 0.001).

Conclusion

Geometric distortion correction in DWI of the breast results in higher similarity of DWI to anatomical non‐EPI T2‐weighted images and would potentially allow for a more reliable lesion segmentation mapping among different MRI modalities. Magn Reson Med 74:1138–1144, 2015. © 2014 Wiley Periodicals, Inc.
Combining phase and magnitude information for contrast agent quantification in dynamic contrast‐enhanced MRI using statistical modeling
Authors: Brynolfsson Patrik , Yu Jun , Wirestam Ronnie , Karlsson Mikael , Garpebring Anders
Published: October 2014

Purpose

The purpose of this study was to investigate, using simulations, a method for improved contrast agent (CA) quantification in DCE‐MRI.

Methods

We developed a maximum likelihood estimator that combines the phase signal in the DCE‐MRI image series with an additional CA estimate, e.g. the estimate obtained from magnitude data. A number of simulations were performed to investigate the ability of the estimator to reduce bias and noise in CA estimates. Noise levels ranging from that of a body coil to that of a dedicated head coil were investigated at both 1.5T and 3T.

Results

Using the proposed method, the root mean squared error in the bolus peak was reduced from 2.24 to 0.11 mM in the vessels and 0.16 to 0.08 mM in the tumor rim for a noise level equivalent of a 12‐channel head coil at 3T. No improvements were seen for tissues with small CA uptake, such as white matter.

Conclusion

Phase information reduces errors in the estimated CA concentrations. A larger phase response from higher field strengths or higher CA concentrations yielded better results. Issues such as background phase drift need to be addressed before this method can be applied in vivo. Magn Reson Med 74:1156–1164, 2015. © 2014 Wiley Periodicals, Inc.
Power balance and loss mechanism analysis in RF transmit coil arrays
Authors: Kuehne Andre , Goluch Sigrun , Waxmann Patrick , Seifert Frank , Ittermann Bernd , Moser Ewald , Laistler Elmar
Published: October 2014

Purpose

To establish a framework for transmit array power balance calculations based on power correlation matrices to accurately quantify the loss contributions from different mechanisms such as coupling, lumped components, and radiation.

Theory and Methods

Starting from Poynting's theorem, power correlation matrices are derived for all terms in the power balance, which is formulated as a matrix equation. Finite‐difference time‐domain simulations of two 7 T eight‐channel head array coils at 297.2 MHz are used to verify the theoretical considerations and demonstrate their application. Care is taken to accurately incorporate all loss mechanisms. The power balance for static B1 phase shims as well as two‐dimensional spatially selective transmit SENSE pulses is shown.

Results

The simulated power balance shows an excellent agreement with theory, with a maximum power imbalance of less than 0.11%. Power loss contributions from the different loss mechanisms vary significantly between the investigated setups, and depending on the excitation mode imposed on the coil.

Conclusion

The presented approach enables a straightforward loss evaluation for an arbitrary excitation of transmit coil arrays. Worst‐case power imbalance and losses are calculated in a straightforward manner. This allows for deeper insight into transmit array loss mechanisms, incorporation of radiated power components in specific absorption rate calculations and verification of electromagnetic simulations. Magn Reson Med 74:1165–1176, 2015. © 2014 Wiley Periodicals, Inc.
Generalized Kronecker product splitting iteration for the solution of implicit Runge–Kutta and boundary value methods
Authors: Chen Hao
Published: October 2014

This paper is concerned with a generalization of the Kronecker product splitting (KPS) iteration for solving linear systems arising in implicit Runge–Kutta and boundary value methods discretizations of ordinary differential equations. It is shown that the new scheme can outperform the standard KPS method in some situations and can be used as an effective preconditioner for Krylov subspace methods. Numerical experiments are presented to demonstrate the effectiveness of the methods. Copyright © 2014 John Wiley & Sons, Ltd.
Dimensionality and Reliability of the Self‐Care of Heart Failure Index Scales: Further Evidence From Confirmatory Factor Analysis
Authors: Barbaranelli Claudio , Lee Christopher S. , Vellone Ercole , Riegel Barbara
Published: October 2014

The Self‐Care of Heart Failure Index (SCHFI) is used widely, but issues with reliability have been evident. Cronbach alpha coefficient is usually used to assess reliability, but this approach assumes a unidimensional scale. The purpose of this article is to address the dimensionality and internal consistency reliability of the SCHFI. This was a secondary analysis of data from 629 adults with heart failure enrolled in three separate studies conducted in the northeastern and northwestern United States. Following testing for scale dimensionality using confirmatory factor analysis, reliability was tested using coefficient alpha and alternative options. Confirmatory factor analysis demonstrated that: (a) the Self‐Care Maintenance Scale has a multidimensional four‐factor structure; (b) the Self‐Care Management Scale has a two‐factor structure, but the primary factors loaded on a common higher‐order factor; and (c) the Self‐Care Confidence Scale is unidimensional. Reliability estimates for the three scales, obtained with methods compatible with each scale's dimensionality, were adequate or high. The results of the analysis demonstrate that issues of dimensionality and reliability cannot be separated. Appropriate estimates of reliability that are consistent with the dimensionality of the scale must be used. In the case of the SCHFI, coefficient alpha should not be used to assess reliability of the self‐care maintenance and the self‐care management scales, due to their multidimensionality. When performing psychometric evaluations, we recommend testing dimensionality before assessing reliability, as well using multiple indices of reliability, such as model‐based internal consistency, composite reliability, and omega and maximal reliability coefficients. © 2014 Wiley Periodicals, Inc.
Community socioeconomic deprivation and obesity trajectories in children using electronic health records
Authors: Nau Claudia , Schwartz Brian S. , Bandeen‐Roche Karen , Liu Anne , Pollak Jonathan , Hirsch Annemarie , Bailey‐Davis Lisa , Glass Thomas A.
Published: October 2014

Objectives

Longitudinal studies of the role of community context in childhood obesity are lacking. The objective of this study was to examine associations of community socio economic deprivation (CSD) with trajectories of change in body mass index (BMI) in childhood and adolescence.

Methods

Data came from electronic health records on 163,473 children aged 3‐18 residing in 1,288 communities in Pennsylvania whose weight and height were measured longitudinally. CSD at the year of birth was measured using six US Census variables and modeled in quartiles. Trajectories of BMI within CSD quartiles were estimated using random effects growth‐curve models accounting for differences by age, sex, and race/ethnicity as well as correcting for non‐constant residual variance across age groups.

Results

CSD was associated with higher BMI at average age (10.7 years) and with more rapid growth of BMI over time. Children born in communities with greater CSD had steeper increases of BMI at younger ages. Those born into the poorest communities displayed sustained accelerated BMI growth. CSD remained associated with BMI trajectories after adjustment for a measure of household socio economic deprivation.

Conclusions

Higher CSD may be associated with more obesogenic growth trajectories in early life. Findings suggest that individual‐level interventions that ignore the effect of community context on obesity‐related behaviors may be less efficient.
Hyaluronic acid/poly‐L‐lysine multilayers coated with gold nanoparticles: cellular response and permeability study
Authors: Prokopović Vladimir Z. , Duschl Claus , Volodkin Dmitry V.
Published: October 2014

Polyelectrolyte multilayer films have been widely studied over the past decade for bioapplications due to their proven reservoir properties for proteins and peptides, growth factors, nucleic acids, drugs, etc. Thick (micrometer‐sized) and soft multilayer films made of biopolymers possess high reservoir capacity but are usually cell repellent. Recently, a new approach has been developed based on physical modification of the films made from hyaluronic acid (HA) and poly‐L‐lysine (PLL) by coating film surface with gold nanoparticles (AuNP). This allows stiffening of the soft HA/PLL film, but still keeps the main part of the film intact to ensure its reservoir ability. Here we have studied cellular adhesion and permeability of the AuNP‐coated films. Different cell types (neuronal SH‐SY5Y, L929 fibroblasts, human embryonic kidney HEK 293 cells, and cervical cancer HELA cells) have been examined. Film free regions formed by mechanical scratching have been used as controls for cellular adhesion. For the permeability study small dye carboxyfluorescein (CF) and large macromolecule (PLL) have been utilized. As found in this study, (HA/PLL)24 films are cell repellent for all considered cell lines. But an improved adhesion to the AuNP‐coated films has been observed for all the cells lines except of HEK. AuNP coating leads to formation of a kind of semipermeable layer on the film surface, which allows small molecules such as CF to diffuse fast into the film, while diffusion of large molecules (PLL) is hindered. Being cell adhesive and selectively permeable AuNP‐coated multilayer films could serve as a novel platform for film‐mediated controlled drug delivery. Copyright © 2014 John Wiley & Sons, Ltd.
Enhancement in thermoelectric power of Ce(Ni1−xCux)2Al3: An implication of two‐band conduction
Authors: Yadam Sankararao , Singh Durgesh , Venkateshwarlu D. , Gangrade Mohan Kumar , Samatham S. Shanmukharao , Ganesan V.
Published: October 2014

The thermoelectric power (TEP), resistivity, and heat capacity of the polycrystalline Ce(Ni1−xCux)2Al3 system, for x = 0.0–0.4, are reported. A clear enhancement of TEP at low temperatures is seen upon substitution of Cu and is expected to be useful for low‐temperature thermoelectric applications. To understand such an enhanced TEP we have employed a two‐band model based on the Ce‐4f and conduction bands proposed by Gottwick et al. A clear evolution of a 4f band moving toward the Fermi level that is becoming sharpened is seen and is predicted to be close to resonance. The fit parameters of the TEP (S) are physically reasonable. The resistivity data shows an evolution from a simple compensated metal to a paramagnetic one via the Kondo route. This is in line with TEP parameters. In addition, a clear enhancement seen in the electronic part of the heat capacity upon Cu substitution and the evolution of magnetoresistance behavior corroborates the results. Possible bipolar effects are also taken into consideration along with an electron–phonon interaction term to explain the almost temperature‐independent part of the resistivity, still yielding a considerable component of disorder.
Using multistate capture–mark–recapture models to quantify effects of predation on age‐specific survival and population growth in black‐tailed deer
Authors: Marescot Lucile , Forrester Tavis D. , Casady David S. , Wittmer Heiko U.
Published: October 2014

Effective species management and conservation relies on accurate estimates of vital rates and an understanding of their link to environmental variables. We used multistate capture–mark–recapture models to directly quantify effects of predation on age‐specific survival of black‐tailed deer Odocoileus hemionus columbianus in California, USA. Survival probabilities were derived from individual encounter histories of 136 fawns and 57 adults monitored over 4 years. Based on results from our survival analysis we parameterized a Lefkovitch matrix and used elasticity analyses to investigate contributions of mortality due to predation to changes in population growth. We found strong evidence for age‐specific survival including senescence. Survival of females >1 year old was consistently low (0.56 ± 0.18 for yearlings, 0.77 ± 0.13 for prime‐aged females, and 0.55 ± 0.08 for senescent individuals), primarily due to high puma Puma concolor predation during summer. Predation from black bears Ursus americanus and coyotes Canis latrans was the primary cause for low annual survival of fawns (0.24 ± 0.16). Resulting estimates of population growth rates were indicative of a strongly declining population (λ = 0.82 ± 0.13). Despite high sensitivity to changes in adult survival, results from a lower‐level elasticity analysis suggested that predation on fawns was the most significant individual mortality component affecting population decline. Our results provide a rare, direct link between predation, age‐specific survival and the predicted population decline of a common ungulate species. The magnitude of predation was unexpected and suggests that ungulates in multi‐predator systems struggle to cope with simultaneous reductions in survival probabilities from predators targeting different age classes.
Applying Public Health Screening Criteria: How Does Universal Newborn Screening Compare to Universal Tumor Screening for Lynch Syndrome in Adults with Colorectal Cancer?
Authors: Cragun Deborah , DeBate Rita D. , Pal Tuya
Published: October 2014

Institutions have increasingly begun to adopt universal tumor screening (UTS) programs whereby tumors from all newly diagnosed patients with colorectal cancer (CRC) are screened to identify who should be offered germline testing for Lynch syndrome (the most common cause of hereditary CRC). Given limited information about the impact of universal screening programs to detect hereditary disease in adults, we apply criteria used to evaluate public health screening programs and compare and contrast UTS with universal newborn screening (NBS) for the purpose of examining ethical implications and anticipating potential outcomes of UTS. Both UTS and a core set of NBS conditions clearly meet most of the Wilson and Jungner screening criteria. However, many state NBS panels include additional conditions that do not meet several of these criteria, and there is currently insufficient data to confirm that UTS meets some of these criteria. Comparing UTS and NBS with regard to newer screening criteria raises additional issues that require attention for both UTS and NBS. Comparisons also highlight the importance of evaluating the implementation of genomic tests to ensure or improve their effectiveness at reducing morbidity and mortality while minimizing potential harms.
Koordination und Führung in der Regionalplanung
Authors: Fürst Dietrich
Published: October 2014

The article intends to link up the discussion on coordination in spatial planning to the on-going discussions on governance and leadership. Coordination has traits of a collective good which provides benefits at large but shifts the burden on individual actors. Leadership in organizations has to master similar difficulties but succeeds by developing among the stake-holders a common mindset of being in the same boat and profiting individually of a successful leadership. But in contrast to leaders in organizations, planners have first to establish the necessary governance arrangements in order to mould stakeholders into a coordinating community interested in collectively fostering the development of the region. Also the tasks of leadership are more difficult because planners do not dispose of the power resources of an organizational leadership. The aim of this paper is to explain why planners could mobilize their poor power resources more effectively.
Entropy conditions for scalar conservation laws with discontinuous flux revisited
Authors: Mitrović Darko , Andreianov Boris
Published: October 2014

We propose new entropy admissibility conditions for multidimensional hyperbolic scalar conservation laws with discontinuous flux which generalize one-dimensional Karlsen–Risebro–Towers entropy conditions. These new conditions are designed, in particular, in order to characterize the limit of vanishing viscosity approximations. On the one hand, they comply quite naturally with a certain class of physical and numerical modeling assumptions; on the other hand, their mathematical assessment turns out to be intricate.

The generalization we propose is not only with respect to the space dimension, but mainly in the sense that the “crossing condition” of Karlsen, Risebro, and Towers (2003) [31] is not mandatory for proving uniqueness with the new definition. We prove uniqueness of solutions and give tools to justify their existence via the vanishing viscosity method, for the multi-dimensional spatially inhomogeneous case with a finite number of Lipschitz regular hypersurfaces of discontinuity for the flux function.
On the existence of multi-transition solutions for a class of elliptic systems
Authors: Rabinowitz Paul H. , Montecchiari Piero
Published: October 2014

The existence of solutions undergoing multiple spatial transitions between isolated periodic solutions is studied for a class of systems of semilinear elliptic partial differential equations. A key tool is a new result on the possible behavior of the set of single transition solutions.
Assessment of benefits and risks in development of targeted therapies for cancer — The view of regulatory authorities
Authors: Pignatti Francesco , Jonsson Bertil , Blumenthal Gideon , Justice Robert
Published: October 2014

Drug licensing and approval decisions involve the balancing of benefits against the risks (harms) in the presence of uncertainty. Typically, the benefits are estimated from primary efficacy endpoints from confirmatory (phase III) clinical trials although exceptions where promising early data from single‐arm studies have led to accelerated approvals are not uncommon, particularly for cancer drugs.

The challenge for regulators is to balance early evidence of efficacy that might support approval versus the need to establish clinical benefit based on conclusive evidence. Targeted agents offer the promise that knowledge about the mechanism of the disease will help identify patients with tumors likely to respond, resulting in higher efficacy and less toxicity, and earlier regulatory decisions based on convincing evidence of clinical benefit.

In this paper, we describe methods and examples of benefit‐risk assessment of targeted drugs, recent initiatives from EMA and FDA on improving communication about benefits and risks, and discuss future steps.