bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformational Preferences of the Full Chicken Prion Protein in Solution and Its Differences with Respect to Mammals
Authors: Pietropaolo Adriana , Muccioli Luca , Zannoni Claudio , Rizzarelli Enrico 
Published: June 2009

AbstractChicken nugget: Simulations of the full chicken prion protein (see picture) and chirality analysis provide possible explanations for its resistance to proteases—and for the fold stability of the avian prion globular core. The three alpha helices exhibit different flexibilities and secondary structure propensities.magnified imageWe investigate the conformations of the full chicken prion protein (ChPrP1‐267) in solution at neutral pH with molecular dynamics simulations. We focus on the persistence of its secondary structure motifs using a recently proposed protein chirality indicator [A. Pietropaolo et al., Proteins 2008, 70, 667–677]. From this, we find a high rigidity of helix 2 (ChPrP178‐195) and of the hexarepeat domain, which is turn rich, and a plasticity of the short β‐sheet, consistent with the available NMR structural details. We also determine the extent of solvation for each residue, revealing local minima for such structured regions. These features hint at a possible origin of the high resistance to proteolysis of the avian prion proteins and of its capability in preventing the aggregation in comparison to mammals.
Homogeneous versus Supported ONN Pincer‐Type Gold and Palladium Complexes: Catalytic Activity
Authors: del Pozo Carolina , Debono Nathalie , Corma Avelino , Iglesias Marta , Sánchez Félix 
Published: June 2009

AbstractThe ONN‐tridentate unsymmetrical pincer‐type (S)‐1‐((6‐(2‐hydroxyphenyl)pyridin‐2‐yl)methyl)‐N‐methyl‐N‐(3‐(triethoxysilyl)pro‐pyl)pyrrolidine‐2‐carboxamide ligand has been synthesized by an easy method, in high purity and good yield. Its respective palladium(II) and gold(III) complexes have been prepared as air‐stable solids. After deprotonation of the OH group the coordination of the metal ion is completely stereospecific and gives rise to only one diastereoisomer. The complexes, immobilized onto ordered mesoporous silica (MCM‐41), are shown to be very active catalysts in the hydrogenation of prochiral olefins (98 % ee was achieved with the heterogenized chiral Au(MCM‐41) complex), hydrosilylation, and Suzuki and Heck CC coupling reactions, under mild conditions. The reactions were studied with the soluble catalysts as well as their heterogenized counterparts. The high accessibility introduced by the structure of the supports allows the preparation of highly efficient immobilized catalysts. The repeated use of the immobilized catalyst in four cycles demonstrates “homogeneous” catalysis with “heterogeneous” catalysts, thus reducing solvent waste and loss of precious metal and/or ligand.
On the two‐port network analysis of common amplifier topologies
Authors: Elwakil A. S. , Maundy B. 
Published: June 2009

AbstractUsing two‐port network transmission parameters, we derive exact expressions for the voltage/current gains and the input/output impedances of common amplifier topologies. The derived expressions are valid both for BJT and MOS‐based amplifiers and are independent of any particular small signal transistor model. Copyright © 2009 John Wiley & Sons, Ltd.
Overview of Strategies for the CVD of Organic Films and Functional Polymer Layers
Authors: Sreenivasan Ramaswamy , Gleason Karen K. 
Published: June 2009

AbstractVapor based polymer deposition methods have evolved to address the limitations of solution polymerization. However this field of vapor based polymerization suffers from varied nomenclature and would benefit from a review article that brought together the different approaches to vapor based polymerization with an effort to present existing nomenclature, clearly identify the various approaches within this field and summarize recent results. This review article is written with the purpose of compiling recent advances in vapor based deposition methods of polymers with a focus on applications that will continue to drive research in this field. We hope that this article encourages researchers engineering novel polymer applications to give vapor based polymerization a serious consideration apart from solution polymerization methods.
PECVD of Fluorocarbon Coatings from Hexafluoropropylene Oxide: Glow vs. Afterglow
Authors: Intranuovo Francesca , Sardella Eloisa , Rossini Pasqua , d'Agostino Riccardo , Favia Pietro 
Published: June 2009

AbstractSmooth and micro/nano‐structured fluorocarbon coatings are obtained by radio frequency (RF), 13.56 MHz, glow discharges fed with hexafluoropropylene oxide (C3F6O, HFPO) both in glow and in afterglow. It is shown that the extent of micro/nanostructuring, as well as the F/C ratio of the coatings, can be precisely tuned with both substrate position and deposition time. Nodular and “stone roses” morphological features are easily obtained, with good reproducibility, by controlling the plasma parameters. Both chemical and morphological features are shown to deeply affect film properties and, in turn, wetability, allowing a move from a hydrophobic behavior to a superhydrophobic one.
Plasticity in the developing brain: Implications for rehabilitation
Authors: Johnston Michael V. 
Published: June 2009

AbstractNeuronal plasticity allows the central nervous system to learn skills and remember information, to reorganize neuronal networks in response to environmental stimulation, and to recover from brain and spinal cord injuries. Neuronal plasticity is enhanced in the developing brain and it is usually adaptive and beneficial but can also be maladaptive and responsible for neurological disorders in some situations. Basic mechanisms that are involved in plasticity include neurogenesis, programmed cell death, and activity‐dependent synaptic plasticity. Repetitive stimulation of synapses can cause long‐term potentiation or long‐term depression of neurotransmission. These changes are associated with physical changes in dendritic spines and neuronal circuits. Overproduction of synapses during postnatal development in children contributes to enhanced plasticity by providing an excess of synapses that are pruned during early adolescence. Clinical examples of adaptive neuronal plasticity include reorganization of cortical maps of the fingers in response to practice playing a stringed instrument and constraint‐induced movement therapy to improve hemiparesis caused by stroke or cerebral palsy. These forms of plasticity are associated with structural and functional changes in the brain that can be detected with magnetic resonance imaging, positron emission tomography, or transcranial magnetic stimulation (TMS). TMS and other forms of brain stimulation are also being used experimentally to enhance brain plasticity and recovery of function. Plasticity is also influenced by genetic factors such as mutations in brain‐derived neuronal growth factor. Understanding brain plasticity provides a basis for developing better therapies to improve outcome from acquired brain injuries. © 2009 Wiley‐Liss, Inc. Dev Disabil Res Rev 2009;15:94–101.
Alpha‐melanocyte‐stimulating hormone attenuates behavioral effects of corticotropin‐releasing factor in isolated guinea pig pups
Authors: Schiml‐Webb Patricia A. , Miller Emily , Deak Terrence , Hennessy Michael B. 
Published: June 2009

AbstractDuring a 3‐hr period of social isolation in a novel environment, guinea pig pups exhibit an initial active phase of behavioral responsiveness, characterized primarily by vocalizing, which is then followed by a stage of passive responsiveness in which pups display a distinctive crouch, eye‐closing, and extensive piloerection. Prior treatment of pups with alpha‐melanocyte‐stimulating hormone (α‐MSH) reduces each of the passive behaviors. The onset of passive responding during separation can be accelerated with peripheral injection of corticotropin‐releasing factor (CRF). To examine whether CRF produces its effects through a mechanism similar to that of prolonged separation, we examined the effect of administering α‐MSH to pups injected with CRF. As expected, CRF markedly enhanced passive responding during a 60‐min period of separation. α‐MSH delivered by either intracerebroventricular infusion or intraperitoneal injection significantly reduced each of the passive behavioral responses without significantly affecting active behavior. These findings, together with previous results indicating that it is the anti‐inflammatory property of α‐MSH that is responsible for its behavioral effects during prolonged separation, suggest that peripheral CRF speeds the induction of passive responding through a mechanism involving enhanced proinflammatory activity. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 399–407, 2009.
Aktuelle Forschungsergebnisse zur Rissbildung in feuerverzinkten Stahlkonstruktionen
Authors: Feldmann Markus , Ulbrich Detlef , Breitschaft Gerhard 
Published: June 2009

Abstract1. Vorbemerkung2. Kurzfassung des Forschungsberichtes 16.132 “Stichprobe zur Erfassung der Verzinkungsschäden an in den Jahren 2000 bis 2005/2006 hergestellten Stahlbauten im Gebiet der Bundesrepublik Deutschland”2.1. Anlass und Zielsetzung2.2. Erste Maßnahmen2.3. Maßnahmen für den gebauten Bestand2.4. Zusammenstellung der geprüften Konstruktionen2.5. Durchführung der Prüfungen vor Ort2.6. Ergebnis der Prüfungen2.7. Zusammenfassung, Schlussfolgerungen und Empfehlungen
High glucose‐induced changes in steroid production in adrenal cells
Authors: Astort F. , Repetto E. M. , Calejman C. Martínez , Cipelli J. M. , Sánchez R. , Di Gruccio J. M. , Mercau M. , Pignataro O. P. , Arias P. , Cymeryng C. B. 
Published: June 2009

AbstractBackgroundIncreased activity of the hypothalamic‐pituitary‐adrenal (HPA) axis, resulting in enhanced adrenocorticotropin (ACTH) and serum glucocorticoid levels, has been described in patients with diabetes mellitus and in animal models of this disease; however, altered steroid production by adrenocortical cells could result from local changes triggered by increased reactive oxygen species (ROS), induced in turn by chronic hyperglycaemia. Experiments were designed (1) to analyse the effects of incubating murine adrenocortical cells in hyperglycaemic media on the generation of oxidative stress, on steroid synthesis and on its modulation by the activity of haeme oxygenase (HO); and (2) to evaluate the effect of antioxidant treatment on these parameters.MethodsY1 cells were incubated for 7 days with either normal or high glucose (HG, 30 mmol/L) concentrations, with or without antioxidant treatment. Parameters of oxidative stress and expression levels of haeme oxygenase‐1 (HO‐1), nitrite levels, L‐arginine uptake and progesterone production were determined.ResultsHG augmented ROS and lipoperoxide production, decreasing glutathione (GSH) levels and increasing antioxidant enzymes and HO‐1 expression. Basal progesterone production was reduced, while a higher response to ACTH was observed in HG‐treated cells. The increase in HO‐1 expression and the effects on basal steroid production were abolished by antioxidant treatment. Inhibition of HO activity increased basal and ACTH‐stimulated steroid release. Similar results were obtained by HO‐1 gene silencing while the opposite effect was observed in Y1 cells overexpressing HO‐1.ConclusionsHG induces oxidative stress and affects steroid production in adrenal cells; the involvement of HO activity in the modulation of steroidogenesis in Y1 cells is postulated. Copyright © 2009 John Wiley & Sons, Ltd.
Sediment transmission and storage: the implications for reconstructing landform development
Authors: Chiverrell R. C. , Foster G. C. , Thomas G. S. P. , Marshall P. 
Published: June 2009

AbstractThe late Holocene (last 3000 years) development of the lower Ribble valley (northwest England) displays evidence for a complex response to a sediment recharge event forced by land‐use change induced increases in erosion and sediment delivery. The deposition of fluvial sediments during the late Holocene was restricted to a series of reaches or depocenters separated by zones with no sediment accumulation constrained by older glacial and fluvial terrain. Apparent reach‐wide correlations of fluvial terraces break down under the scrutiny applied by comprehensive and extensive radiocarbon control. Bayesian testing of relative order models show that large‐scale geomorphological changes, e.g. the progression from one terrace level to another, were time transgressive between different depocenters. The different histories of sediment delivery and storage are probably a function of local‐ and process‐scale variations in these depocenters, and reflect (dis)connectivity relationships within a reach in propagating a basin‐scale change (superslug) in the sediment regime. Disconnectivity in the depositional regime through a fluvial reach limits what we can reconstruct in terms of sediment budgets, but radiocarbon dating of multiple palaeochannels offers considerable potential for landform‐based research to uncover rates of change within individual depocenters. Copyright © 2009 John Wiley & Sons, Ltd.
Beating capillarity in thin film flows
Authors: Sellier Mathieu , Panda Satyananda 
Published: June 2009

AbstractThe combination of substrate unevenness and capillarity is known to induce far‐reaching perturbations at the free surface of thin liquid films. These might be undesired and this paper explores the possibility to control the free surface of thin liquid films to give it a prescribed profile by a suitable design of the underlying substrate. This corresponds to the inverse of the widely studied forward problem, which considers the effect of substrate unevenness on a free surface. Assuming that the steady free surface profile can be described by the lubrication approximation, this optimal control problem is shown to be governed by a first‐order partial differential equation, which is solved numerically using the method of characteristics. The proposed method is successfully tested for a range of desired free surface profiles and the domain of existence of a solution to the inverse problem is probed. Expectedly, it is shown that, owing to surface tension, not all free surface profiles can be achieved but in some cases capillarity can be beaten and a prescribed free surface profile obtained. Copyright © 2009 John Wiley & Sons, Ltd.
An EBE finite element method for simulating nonlinear flows in rotating spheroidal cavities
Authors: Chan Kit H. , Zhang Keke , Liao Xinhao 
Published: June 2009

AbstractMany planetary and astrophysical bodies are rotating rapidly, fluidic and, as a consequence of rapid rotation, in the shape of an ablate spheroid. We present an efficient element‐by‐element (EBE) finite element method for the numerical simulation of nonlinear flows in rotating incompressible fluids that are confined in an ablate spheroidal cavity with arbitrary eccentricity. Our focus is placed on temporal and spatial tetrahedral discretization of the EBE finite element method in spheroidal geometry, the EBE parallelization scheme and the validation of the nonlinear spheroidal code via both the constructed exact nonlinear solution and the special resonant forcing in the inviscid limit. Copyright © 2009 John Wiley & Sons, Ltd.
Prediction of spatial displacement development
Authors: Pilgerstorfer Thomas , Radončić Nedim 
Published: June 2009

AbstractOne of the major shortcomings of two‐dimensional approaches for underground excavation design is the (mostly) inadequate modelling of the effects of the face advance. Although they may roughly estimate the evolution of the displacements towards their final value, none of the 2D solutions available so far provide information about the extent of the pre‐relaxation the ground has undergone. On the other hand, 3D calculations pose a much greater effort in modelling and evaluation, and can be conducted only by using numerical methods.The method presented in this paper is intended to narrow this gap, representing an easy‐to‐implement tool allowing fast assessment of displacement development for a circular cavity in a linearly elastic‐ideally plastic Mohr‐Coulomb material under hydrostatic loading. A numerical parametric study has been performed on a 3D model in FLAC3D. The parameters for the numerical simulations were chosen in such a way that they form a regular grid in a co‐ordinate system spanned by the friction angle and a non‐dimensional variable defined as the ratio between the depth of failure and the tunnel radius. Based on the displacement data obtained from numerical simulations, the respective fictitious support pressures have been back‐calculated for every face position, using the closed‐form solution developed by Feder & Arwanitakis. The back‐calculated curves of the fictitious support pressure, its dimensionless form λ (equivalent support pressure coefficient), defined as the ratio between the fictitious support pressure and the primary stress respectively, have been fitted with a slightly modified version of the function proposed by Sulem et al. The fitting process yields function shape parameters, allowing the establishment of three interpolation relationships. The knowledge of the shape parameters for an arbitrary set of mechanical parameters allows the calculation of the displacement path. The results have been verified on a set of ten 3D calculations with a random set of parameters and show very good agreement in all cases. In addition, the presented method is demonstrated through case histories.
Monitoring the deformation of a temporary top heading invert using Time Domain Reflectometry
Authors: Singer John , Grafinger Helge , Thuro Kurosch 
Published: June 2009

AbstractFor the objective evaluation of the structural safety of tunnel structures during the construction phase, continuous monitoring of all important structural elements (e.g. tunnel lining) and the tunnel face are of utmost importance. The temporary top heading invert, frequently used in sensitive areas of top heading drives, could not up to now be monitored with measuring equipment, because it is usually covered with infill to form a temporary haul road.The application of a Time Domain Reflectometry (TDR) measurement system makes it possible for the first time to detect, localise and quantify failures in the shotcrete lining. The calibration of the TDR measurement system in laboratory tests and the experience gained through a practical trial in the Lainzer tunnel in Vienna have made it possible to determine the capabilities and limits of this measuring system and demonstrate its readiness for practical use.
Low cost 3D early warning system for instable alpine slopes – the Aggenalm Landslide monitoring system
Authors: Thuro Kurosch , Wunderlich Thomas , Heunecke Otto , Singer John , Schuhbäck Stefan , Wasmeier Peter , Glabsch Jessica , Festl Judith 
Published: June 2009

AbstractIn context of global climate change and the continuous extension of settlement areas in the Alps, especially due to tourism, an increasing conflict can be observed between land use and natural hazard prevention. This also includes deep‐seated landslides, which can cause considerable damage to settlements and infrastructure when they occur and even endanger lives.The hazard potential of slow deep‐seated landslides has often been underestimated up till now. For economic reasons, such potentially dangerous instable slopes often are only monitored sporadically if at all. The alpEWAS project (“development and testing of an integrative 3D early warning system for instable alpine slopes”) is currently developing a low cost 3D monitoring and early warning system for landslides based on three innovative continuous measurement systems for underground and surface deformations: Time Domain Reflectometry, reflectorless video tacheometry and low cost global navigation satellite system. These are merged with other sensors, which monitor typical trigger mechanisms (e.g. precipitation), into a geo sensor network, providing remote online access to all data in near real time in a WebGIS environment.The alpEWAS system has been installed at the Aggenalm Landslide for a first field test. The experiences made there will be of great importance for the medium‐term goal: the development of a market‐ready, flexible and economic early warning system for landslides.
Differential activation of the human trigeminal nuclear complex by noxious and non‐noxious orofacial stimulation
Authors: Nash Paul G. , Macefield Vaughan G. , Klineberg Iven J. , Murray Greg M. , Henderson Luke A. 
Published: June 2009

AbstractThere is good evidence from animal studies for segregation in the processing of non‐nociceptive and nociceptive information within the trigeminal brainstem sensory nuclear complex. However, it remains unknown whether a similar segregation occurs in humans, and a recent tract tracing study suggests that this segregation may not exist. We used functional magnetic resonance imaging (fMRI) to define and compare activity patterns of the trigeminal brainstem nuclear complex during non‐noxious and noxious cutaneous and non‐noxious and noxious muscle orofacial stimulation in humans. We found that during cutaneous pain, signal intensity increased within the entire rostrocaudal extent of the spinal trigeminal nucleus (SpV), encompassing the ipsilateral oralis (SpVo), interpolaris (SpVi) and caudalis (SpVc) subdivisions. In contrast, muscle pain did not activate SpVi, but instead activated a discrete region of the ipsilateral SpVo and SpVc. Further, muscle noxious stimulation activated a region of the ipsilateral lateral pons in the region of the trigeminal principal sensory nucleus (Vp). Innocuous orofacial stimulation (lip brushing) also evoked a significant increase in signal intensity in the ipsilateral Vp; however, non‐noxious muscle stimulation showed no increase in signal in this area. The data reveal that orofacial cutaneous and muscle nociceptive information and innocuous cutaneous stimulation are differentially represented within the trigeminal nuclear complex. It is well established that cutaneous and muscle noxious stimuli evoke different perceptual, behavioural and cardiovascular changes. We speculate that the differential activation evoked by cutaneous and muscle noxious stimuli within the trigeminal sensory complex may contribute to the neural basis for these differences. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Sex‐dependent effects of 56Fe irradiation on contextual fear conditioning in C57BL/6J mice
Authors: Villasana Laura , Rosenberg Jenna , Raber Jacob 
Published: June 2009

AbstractEffects of irradiation on hippocampal function have been mostly studied in male rodents and relatively little is known about potential effects of irradiation on hippocampal function in female rodents. Moreover, although the long‐term effects of clinical radiation on cognitive function have been well established, the effects of other forms of irradiation, such as high charged, high energy radiation (HZE particles) that astronauts encounter during space missions have not been well characterized. In this study we compared the effects of 56Fe irradiation on fear conditioning in C57BL/6J female and male mice. Hippocampus‐dependent contextual fear conditioning was impaired in female mice but improved in male mice following 56Fe irradiation. Such impairment was not seen for hippocampus‐independent cued fear conditioning. Thus, the effects of 56Fe irradiation on hippocampus‐dependent contextual fear conditioning are critically modulated by sex. © 2009 Wiley‐Liss, Inc.