bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoporous carbon — metal composites for hydrogen storage
Authors: Giasafaki Dimitra , Bourlinos Athanassios , Charalambopoulou Georgia , Stubos Athanassios , Steriotis Theodore 
Published: July 2011

Abstract
Metal-carbon composites have shown considerable hydrogen storage potential at room temperature. In the present work the behaviour of two different Pd amalgam doped carbon substrates, namely a carbogenic foam and a mildly oxidised ordered mesoporous carbon, are compared on the basis of their hydrogen sorption properties at 77 and 298 K and low pressures, aiming to investigate the effect of surface on the storage capacity. In both cases, the introduction of alloy nanoparticles leads to an improvement of the hydrogen uptake with respect to pure carbons. This effect is significant for the carbogenic foam however small for the ordered carbon.
Intramolecular N to N acyl migration in conformationally mobile 1′-acyl-1-benzyl-3′,4′-dihydro-1′H-spiro[piperidine-4,2′-quinoline] systems promoted by debenzylation conditions (HCOONH4/Pd/C)
Authors: Méndez Leonor , Kouznetsov Vladimir 
Published: July 2011

Abstract
We report an efficient and useful synthesis of new attractive spiropiperdine scaffolds 4 based on an intramolecular acyl transfer process in 1′-acyl-1-benzyl-3′,4′-dihydro-1′H-spiro[piperidine-4,2′-quinolines] 3 using simple and mild debenzylation reaction conditions (HCOONH4/Pd/C). The compounds 3 were prepared by acylating 1-benzyl-4′-methyl-3′,4′-dihydro-1′H-spiro[piperidine-4,2′-quinolines] 2 that are easily available from 1-benzyl-4-piperidone 1. The intramolecular character of this process was proven primarily through a crossover experiment technique. Through an examination of all spectroscopic information (1H, 13C NMR, VT-1H NMR, and 2D NMR) it was possible to correctly predict amide configurations and piperidine ring conformations of starting and final spiropiperidine compounds.
L'ombre révélatrice. Caricature, personnification, allégorie
Authors: Guédron Martial 
Published: July 2011

Dans la tradition académique, l’allégorie est définie comme une sélection d’objets qui servent à représenter autre chose que ce qu’ils sont en effet. Or si une telle définition évoque d’abord d’ambitieuses compositions à clés, on peut aussi la rapporter à l’un des stratagèmes les plus fréquents de la caricature. Il en est ainsi lorsque, jouant sur des détails incongrus, le caricaturiste signale un sens caché tout en le rendant assez lisible pour que sa compréhension s’impose au spectateur. C’est ce processus qui est à l’œuvre dans le motif étudié ici : l’altération de l’ombre portée d’un personnage comme moyen de révéler sa part obscure. Dans l’utilisation qu’ils en ont faite, Piercy Roberts, Jean-Jacques-Isidore Gérard, dit Grandville et Honoré Daumier témoignent de ce que l’ombre allégorique a souvent un contenu politique et satirique. Avec eux, l’artiste se transforme en montreur d’ombres qui révèle au spectateur la véritable nature, foncièrement mauvaise, des hommes de pouvoir dont l’apparence officielle n’est que tromperie et artifice.
Allégorie et tautologie : la politique du poème, de Baudelaire à Mallarmé
Authors: Monginot Benoît 
Published: July 2011

Mallarmé s’oppose à Baudelaire sur une question de poétique. L’allégorie débouche dans ses poèmes sur une mise en relief de la dimension tautologique de tout acte de signification. Nous montrons ici comment cette opposition poétique est un affrontement politique : Mallarmé en redéfinissant l’allégorie redéfinit consciemment les modalités du partage du sens. La pensée de l’allégorie est explicitement chez lui une réflexion sur la communauté, une économie de la violence.
Cytokine-Induced Alterations of α7 Nicotinic Receptor in Colonic CD4 T Cells Mediate Dichotomous Response to Nicotine in Murine Models of Th1/Th17- versus Th2-Mediated Colitis
Authors: Galitovskiy Valentin , Qian Jing , Chernyavsky Alexander I. , Marchenko Steve , Gindi Vivian , Edwards Robert A. , Grando Sergei A. 
Published: July 2011

AbstractUlcerative colitis (UC) and Crohn’s disease (CD) are two forms of chronic inflammatory bowel disease. CD4 T cells play a central role in the pathogenesis of both diseases. Smoking affects both UC and CD but with opposite effects, ameliorating UC and worsening CD. We hypothesized that the severity of gut inflammation could be modulated through T cell nicotinic acetylcholine receptors (nAChRs) and that the exact clinical outcome would depend on the repertoire of nAChRs on CD4 T cells mediating each form of colitis. We measured clinical and immunologic outcomes of treating BALB/c mice with oxazolone- and trinitrobenzene sulfonic acid (TNBS)-induced colitides by nicotine. Nicotine attenuated oxazolone colitis, which was associated with an increased percentage of colonic regulatory T cells and a reduction of Th17 cells. TCR stimulation of naive CD4+CD62L+ T cells in the presence of nicotine upregulated expression of Foxp3. In marked contrast, nicotine worsened TNBS colitis, and this was associated with increased Th17 cells among colonic CD4 T cells. Nicotine upregulated IL-10 and inhibited IL-17 production, which could be abolished by exogenous IL-12 that also abolished the nicotine-dependent upregulation of regulatory T cells. The dichotomous action of nicotine resulted from the up- and downregulation of anti-inflammatory α7 nAChR on colonic CD4 T cells induced by cytokines characteristic of the inflammatory milieu in oxazolone (IL-4) and TNBS (IL-12) colitis, respectively. These findings help explain the dichotomous effect of smoking in patients with UC and CD, and they underscore the potential for nicotinergic drugs in regulating colonic inflammation.
Long-Distance Regulation of Fetal Vδ Gene Segment TRDV4 by the Tcrd Enhancer
Authors: Hao Bingtao , Krangel Michael S. 
Published: July 2011

Abstract
Murine Tcra and Tcrd gene segments are organized into a single genetic locus (Tcra/Tcrd locus) that undergoes V(D)J recombination in CD4−CD8− double-negative (DN) thymocytes to assemble Tcrd genes and in CD4+CD8+ double-positive thymocytes to assemble Tcra genes. Recombination events are regulated by two developmental stage-specific enhancers, Eδ and Eα. Effects of Eα on Trca/Tcrd locus chromatin have been well documented, but effects of Eδ have not. In this regard, Eα acts over long distances to activate many Vα and Jα segments for recombination in double-positive thymocytes. However, in DN thymocytes, it is unclear whether Eδ functions over long distances to regulate Vδ gene segments or functions only locally to regulate Dδ and Jδ gene segments. In this study, we analyzed germline transcription, histone modifications, and recombination on wild-type and Eδ-deficient alleles in adult and fetal thymocytes. We found that Eδ functions as a local enhancer whose influence is limited to no more than ∼10 kb in either direction (including Dδ, Jδ, and TRDV5 gene segments) in adult DN thymocytes. However, we identified a unique long-distance role for Eδ promoting accessibility and recombination of fetal Vδ gene segment TRDV4, over a distance of 55 kb, in fetal thymocytes. TRDV4 recombination is specifically repressed in adult thymocytes. We found that this repression is enforced by a developmentally regulated loss of histone acetylation. Constitutively high levels of a suppressive modification, histone H3 lysine 9 dimethylation, may contribute to repression as well.
Chronic Fetal Exposure to Ureaplasma parvum Suppresses Innate Immune Responses in Sheep
Authors: Kallapur Suhas G. , Kramer Boris W. , Knox Christine L. , Berry Clare A. , Collins Jennifer J. P. , Kemp Matthew W. , Nitsos Ilias , Polglase Graeme R. , Robinson James , Hillman Noah H. , Newnham John P. , Chougnet Claire , Jobe Alan H. 
Published: July 2011

Abstract
The chorioamnionitis associated with preterm delivery is often polymicrobial with ureaplasma being the most common isolate. To evaluate interactions between the different proinflammatory mediators, we hypothesized that ureaplasma exposure would increase fetal responsiveness to LPS. Fetal sheep were given intra-amniotic (IA) injections of media (control) or Ureaplasma parvum serovar 3 either 7 or 70 d before preterm delivery. Another group received an IA injection of Escherichia coli LPS 2 d prior to delivery. To test for interactions, IA U. parvum-exposed animals were challenged with IA LPS and delivered 2 d later. All animals were delivered at 124 ± 1-d gestation (term = 150 d). Compared with the 2-d LPS exposure group, the U. parvum 70 d + LPS group had 1) decreased lung pro- and anti-inflammatory cytokine expression and 2) fewer CD3+ T lymphocytes, CCL2+, myeloperoxidase+, and PU.1+ cells in the lung. Interestingly, exposure to U. parvum for 7 d did not change responses to a subsequent IA LPS challenge, and exposure to IA U. parvum alone induced mild lung inflammation. Exposure to U. parvum increased pulmonary TGF-β1 expression but did not change mRNA expression of either the receptor TLR4 or some of the downstream mediators in the lung. Monocytes from fetal blood and lung isolated from U. parvum 70 d + LPS but not U. parvum 7 d + LPS animals had decreased in vitro responsiveness to LPS. These results are consistent with the novel finding of downregulation of LPS responses by chronic but not acute fetal exposures to U. parvum. The findings increase our understanding of how chorioamnionitis-exposed preterm infants may respond to lung injury and postnatal nosocomial infections.
Mycobacterium tuberculosis Triggers Host Type I IFN Signaling To Regulate IL-1β Production in Human Macrophages
Authors: Novikov Aleksey , Cardone Marco , Thompson Robert , Shenderov Kevin , Kirschman Kevin D. , Mayer-Barber Katrin D. , Myers Timothy G. , Rabin Ronald L. , Trinchieri Giorgio , Sher Alan , Feng Carl G. 
Published: July 2011

Abstract
Mycobacterium tuberculosis is a virulent intracellular pathogen that survives in macrophages even in the presence of an intact adaptive immune response. Type I IFNs have been shown to exacerbate tuberculosis in mice and to be associated with disease progression in infected humans. Nevertheless, the mechanisms by which type I IFNs regulate the host response to M. tuberculosis infection are poorly understood. In this study, we show that M. tuberculosis induces an IFN-related gene expression signature in infected primary human macrophages, which is dependent on host type I IFN signaling as well as the mycobacterial virulence factor, region of difference-1. We further demonstrate that type I IFNs selectively limit the production of IL-1β, a critical mediator of immunity to M. tuberculosis. This regulation occurs at the level of IL1B mRNA expression, rather than caspase-1 activation or autocrine IL-1 amplification and appears to be preferentially used by virulent mycobacteria since avirulent M. bovis bacillus Calmette-Guérin (BCG) fails to trigger significant expression of type I IFNs or release of mature IL-1β protein. The latter property is associated with decreased caspase-1–dependent IL-1β maturation in the BCG-infected macrophages. Interestingly, human monocytes in contrast to macrophages produce comparable levels of IL-1β in response to either M. tuberculosis or BCG. Taken together, these findings demonstrate that virulent and avirulent mycobacteria employ distinct pathways for regulating IL-1β production in human macrophages and reveal that in the case of M. tuberculosis infection the induction of type I IFNs is a major mechanism used for this purpose.
Zinc Finger Protein Tristetraprolin Interacts with CCL3 mRNA and Regulates Tissue Inflammation
Authors: Kang Ju-Gyeong , Amar Marcelo J. , Remaley Alan T. , Kwon Jaeyul , Blackshear Perry J. , Wang Ping-yuan , Hwang Paul M. 
Published: July 2011

Abstract
Zinc finger protein tristetraprolin (TTP) modulates macrophage inflammatory activity by destabilizing cytokine mRNAs. In this study, through a screen of TTP-bound mRNAs in activated human macrophages, we have identified CCL3 mRNA as the most abundantly bound TTP target mRNA and have characterized this interaction via conserved AU-rich elements. Compared to the wild-type cells, TTP−/− macrophages produced higher levels of LPS-induced CCL3. In addition, the plasma level of CCL3 in TTP−/− mice was markedly higher than that in wild-type mice. To determine the in vivo significance of TTP-regulated CCL3, we generated CCL3−/−TTP−/− double-knockout mice. Along with decreased proinflammatory cytokines in their paw joints, there were significant functional and histologic improvements in the inflammatory arthritis of TTP−/− mice when CCL3 was absent, although cachexia, reflecting systemic inflammation, was notably unaffected. Furthermore, the marked exacerbation of aortic plaque formation caused by TTP deficiency in the APOE−/− mouse model of atherosclerosis was also rescued by disrupting CCL3. Taken together, our data indicate that the interaction between TTP and CCL3 mRNA plays an important role in modulating localized inflammatory processes in tissues that are dissociated from the systemic manifestations of chronic inflammation.
Growth, structure and optical characterization of Al‐doped ZnO nanoparticle thin films
Authors: Prajapati C. S. , Sahay P. P. 
Published: July 2011

AbstractAl‐doped ZnO nanoparticle thin films were prepared on glass substrate at the optimum temperature of (410±10) °C by spray pyrolysis technique using zinc nitrate as a precursor solution and aluminium chloride as a dopant. The dopant concentration (Al/Zn at%) was varied from 0 to 2 at%. Structural analysis of the films shows that all the films are of polycrystalline zinc oxide in nature, possessing hexagonal wurtzite structure. The films exhibit variation in peak intensities corresponding to (100), (002) and (101) reflection planes on Al‐doping. The crystallite size calculated by Scherrer formula has been found to be in the range of 35‐65 nm. The optical absorption study shows that the optical band gap in the Al‐doped films varies in the range of 3.11 – 3.22 eV. The width of localized states in the band gap estimated by the Urbach tail analysis has been found to be minimum in case of the 1 at% Al‐doped zinc oxide thin film. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Iterative frequency‐domain detection and channel estimation for space–time block codes
Authors: Marques da Silva Mário , Dinis Rui 
Published: July 2011

ABSTRACTIn this paper, we consider iterative frequency‐domain receivers for block transmission techniques with rate‐1 space–time block coding (STBC) for two or four transmit antennas. Single carrier with frequency‐domain equalisation (SC‐FDE) combined with antenna diversity is a promising candidate for future broadband wireless systems. Because our STBC with four transmit antennas is not orthogonal, our receiver includes the cancellation of the residual interference, allowing performances close to the ones of an orthogonal code.We propose an iterative STBC receiver that considers an iterative detection and channel estimation. The channel estimates usually obtained with the help of pilot symbols and/or training sequences are multiplexed with data symbols. Because this leads to spectral degradation, the use of superimposed pilots (i.e. pilots added to data) was recently proposed as an efficient alternative. Our performance results show that the proposed SC‐FDE STBC receiver allows excellent performance with the use of the channel data obtained from the channel estimation. Copyright © 2011 John Wiley & Sons, Ltd.
Mechanics of Homeotropically Ordered Smectic‐A Elastomers with Global Oblate Chain Conformation
Authors: Kramer Dominic , Finkelmann Heino 
Published: July 2011

AbstractSmectic‐A elastomers combine one‐dimensional translational order of rod‐like segments with the rubber elasticity of a polymer network. In recent years, detailed investigations were carried out on elastomers showing a global prolate chain conformation. In this communication, the first experiments on fluorinated SAelastomers exhibiting a global oblate chain conformation are presented, where the polymer chains are on average compressed along the layer normal of the lamellar phase structure. The mechanical anisotropy is studied by means of thermoelastic experiments and stress–strain measurements. For the first time, the layer compression modulusBof smectic elastomers is directly measured.Bis significantly larger as compared to conventional low molar mass liquid crystals and decreases significantly with increasing local disorder introduced by the isotropic crosslinker.magnified image
Generalized‐Yvon–Born–Green Model of Toluene
Authors: Ellis Christopher R. , Rudzinski Joseph F. , Noid William G. 
Published: July 2011

AbstractCoarse‐grained (CG) models provide a highly efficient computational means for investigating complex processes that evolve on large length‐scales or long time‐scales. The predictive capability of these models relies upon their ability to reproduce the relevant structural properties of accurate, though prohibitively expensive, atomistic models. The many‐body potential of mean force (PMF) is the appropriate potential for a CG model that quantitatively reproduces the structure of an underlying atomistic model. Because this PMF cannot be readily calculated or simulated, several methods attempt to systematically approximate this PMF with relatively simple molecular mechanics potentials. Recently, we have proposed a generalized‐Yvon–Born–Green (g‐YBG) approach to determine approximate potentials for accurate CG models directly from structural information. In the present work, we demonstrate the mechanism by which the g‐YBG approach employs simple structural information to characterize and approximate the many‐body PMF. We then employ this approach to parameterize a three site CG model for liquid toluene. We demonstrate that this model accurately reproduces the structural properties of an all‐atom model. Moreover, using this model system, we demonstrate the variational nature of the method and investigate the sensitivity of the model to the CG mapping. Finally, we briefly investigate the transferability of the CG model to different temperatures.magnified image
On the optimal control of a linear neutral differential equation arising in economics
Authors: Boucekkine Raouf , Fabbri Giorgio , Pintus Patrick 
Published: July 2011

SUMMARYIn this paper, we apply two optimization methods to solve an optimal control problem of a linear neutral differential equation (NDE) arising in economics. The first one is a variational method, and the second follows a dynamic programming approach. Because of the infinite dimensionality of the NDE, the second method requires the reformulation of the latter as an ordinary differential equation in an appropriate abstract space. It is shown that the resulting Hamilton–Jacobi–Bellman equation admits a closed‐form solution, allowing for a much finer characterization of the optimal dynamics compared with the alternative variational method. The latter is clearly limited by the nontrivial nature of asymptotic analysis of NDEs. Copyright © 2011 John Wiley & Sons, Ltd.
Co‐optimization of emitter profile and metal grid of selective emitter silicon solar cells
Authors: Wen Zhenli , Zhou Chunlan , Wang Wenjing 
Published: July 2011

ABSTRACTCo‐optimization of the metallization and emitter dopant profile is fully investigated for selective emitter crystalline silicon solar cells. The simulation parameters for the laser doping selective emitter, metallization by plating, silicon nitride passivation, and aluminum back surface field are identified and reached. Internal light flux reflection is also considered in the model. In particular, the influence of the increased light trapping ability of a textured surface on the optimization results is clarified by comparing a cell with a non‐textured surface. In this paper, the optimization results, including the electrical performances of a solar cell are discussed in detail. On the basis of these simulation results, an optimized metallization and emitter dopant profile is proposed. Copyright © 2011 John Wiley & Sons, Ltd.
A Material Model for TRIP‐Steels and its Application to a CrMnNi Cast Alloy
Authors: Prüger Stefan , Kuna Meinhard , Wolf Steffen , Krüger Lutz 
Published: July 2011

AbstractA material model is presented that accounts for strain rate dependent inelastic deformation and strain‐induced phase transformation in TRIP‐steels. Modifications for the kinetics equations of the strain‐induced phase transformation, introduced by Stringfellow, are proposed to overcome a drawback of Stringfellow's model. A parameter identification strategy that relies on Gauss‐Markov estimates is used to determine the model parameters from experimental data of a recently developed cast TRIP‐steel. Good agreement is observed between experimental results of the compression test and the corresponding finite element simulation employing the proposed model. This forms the basis for future applications of the material model in the design of composites and structures.
Interfacial Reactions in TRIP‐Steel/ZrO2 Composites
Authors: Franke P. , Ksyta M. , Seifert H.J. 
Published: July 2011

AbstractThe interfaces between stainless TRIP steel and three types of zirconia ceramics were investigated after sintering the samples for 48 h at 1400 °C. The samples were prepared by embedding compact pieces of ceramics into steel powder and densifying them with a spark plasma equipment. In all experiments the same steel was used but the zirconia ceramics was stabilised with CaO, MgO, or non‐stabilised, respectively. It was found that no reaction product was formed in the samples with non‐stabilised or CaO‐stabilised ceramics. At the interface of MgO‐stabilised zirconia and steel, a layer of forsterite, Mg2SiO4, was formed. The silicate layer resulted from the reaction of MgO which was dissolved in the zirconia with Si which was an impurity in the steel. In a thermodynamic analysis the reasons are explained which lead to the formation of a silicate in the samples with MgO‐stabilised zirconia. Accordingly, thermodynamic calculations are in accord with the absence of a reaction layer in the cases of the non‐stabilised and the CaO‐stabilised zirconia, even though the Gibbs energy of formation of calcium silicates is much higher than that of the corresponding magnesium silicates. The maximum impurity level for silicon in the given steel is calculated which avoids the formation of a silicate layer at the interface of the MgO‐stabilised ceramics.
Factors Predicting the Success of Extracorporeal Shock Wave Lithotripsy in the Treatment of Ureteric Calculi
Authors: Farrands R. , Turney B.W. , Kumar P.V.S. 
Published: July 2011

Objective: To evaluate the success of extracorporeal shock wave lithotripsy (ESWL) in the treatment of ureteric calculi and determine the factors which influence outcome. Patients and methods: A retrospective audit of patients with a single ureteric stone receiving ESWL was performed. Success was defined as complete stone clearance on post-treatment imaging. Patient demographics and stone characteristics were correlated to ESWL outcome. Results: 108 patients met the inclusion criteria for this study. The mean age of the patients was 52.5 years (range 24–89 years). 80% (86/108) of patients were male. Stone sizes varied from 4 to 19 mm (mean 7.92 mm). The overall ESWL success rate for ureteric stones was 79%. Treatment was more effective for smaller ( p = 0.003) and more located stones ( p = 0.035). Stone size correlated with number of treatments required ( p =0.005). A JJ stent in situ at the time of ESWL reduced the success rate ( p = 0.002). Conclusions: Stone size, site in the ureter, and the presence of a JJ stent were predictors of ESWL success. Our study from a District General Hospital in the UK demonstrates that ESWL may be used with high efficacy to treat ureteric stones.