bluuebunny/crossref_metadata_2025_split huggingface dataset:
An algorithm for the computation of multiple Hopf bifurcation points based on Pade approximants
Authors: Girault G. , Guevel Y. , Cadou J.M. 
Published: June 2011

SUMMARYRecently, a numerical method was proposed to compute a Hopf bifurcation point in fluid mechanics. This numerical method associates a bifurcation indicator and a Newton method. The former gives initial guesses to the iterative method. These initial values are the minima of the bifurcation indicator. However, sometimes, these minima do not lead to the convergence of the Newton method. Moreover, as only a single initial guess is obtained for each computation of the indicator, the computational time to obtain a Hopf bifurcation point can be quite long. The present algorithm is an enhancement of the previous one. It consists in automatically computing several initial guesses for each indicator curve. The majority of these initial values leads to the convergence of the Newton method. This method is evaluated through the problem of the lid‐driven cavity with several aspect ratios in the framework of the finite element analysis of the 2D Navier–Stokes equations. The results prove the efficiency and the robustness of the proposed algorithm. Copyright © 2011 John Wiley & Sons, Ltd.
Die Prothesen der Zukunft
Authors: Lenarz Thomas 
Published: June 2011

AbstractAbbaubare Knochenschrauben, individualisierter Gelenkersatz, nervenzellfreundliche Hörimplantate: Dank neuer Fertigungstechniken und bioaktiver Materialien lässt sich nicht nur die Haltbarkeit, sondern auch die Funktion verschiedenster Prothesen gezielt verändern – und immer besser an den Organismus anpassen.
Fingolimod: new oral treatment for multiple sclerosis
Authors: Rog David 
Published: June 2011

AbstractFingolimod, a sphingosine‐1‐phosphate receptor modulator, is a novel oral treatment for multiple sclerosis. In this Drug profile the author reviews its mode of action, likely positioning and the advantages that it might offer in terms of clinical management of multiple sclerosis, and begins by setting the treatment context.
CCS – between a rock and a hard place?
Authors: Chadwick Andrew 
Published: June 2011

AbstractFor the past decade and a half, CO2 has been stored underground successfully, and scientists are becoming increasingly confident that carbon dioxide capture and storage (CCS) can work at the required scale. But many people are still not convinced about its viability and are worried about costs. Andrew Chadwick, Consultant Editor, considers what needs to be done to reassure the public and the investment community
The origins of glioma: E Pluribus Unum?
Authors: Siebzehnrubl F. A. , Reynolds B. A. , Vescovi A. , Steindler D. A. , Deleyrolle L. P. 
Published: June 2011

AbstractMalignant glioma is among of the most devastating, and least curable, types of cancer. Since the re‐emergence of the cancer stem cell hypothesis, much progress has been made towards elucidating the cellular origin of these tumors. The hypothesis that tumors are hierarchically organized, with a cancer stem cell at the top that shares defining features with somatic stem cells and provides therapeutic refractoriness properties, has put adult stem cells into the limelight as prime suspect for malignant glioma. Much confusion still exists, though, as to the particular cell type and processes that lead to oncogenic transformation. In this review, we will discuss recent developments and novel hypotheses regarding the origin of malignant gliomas, especially glioblastoma. In particular, we argue that glioblastoma is the result of different pathways originating in multiple sources that all ultimately converge in the same disease. Further attention is devoted to potential scenarios leading to transformation of different stem/progenitor cell types of the brain, and the probability and relevance of these scenarios for malignant tumorigenesis. © 2011 Wiley‐Liss, Inc.
Evaluation of a virtual reality‐based memory training programme for Hong Kong Chinese older adults with questionable dementia: a pilot study
Authors: Man David W. K. , Chung Jenny C. C. , Lee Grace Y. Y. 
Published: June 2011

BackgroundOlder adults with questionable dementia are at risk of progressing to dementia, and early intervention is considered important. The present study investigated the effectiveness of a virtual reality (VR)‐based memory training for older adults with questionable dementia.MethodsA pre‐test and post‐test design was adopted. Twenty and 24 older adults with questionable dementia were randomly assigned to a VR‐based and a therapist‐led memory training group, respectively. Primary outcome measures included the Multifactorial Memory Questionnaire and Fuld Object Memory Evaluation.ResultsBoth groups demonstrated positive training effects, with the VR group showing greater improvement in objective memory performance and the non‐VR group showing better subjective memory subtest results in the Multifactorial Memory Questionnaire.ConclusionThe use of VR seems to be acceptable for older adults with questionable dementia. Further study on the effect of educational background and memory training modality (visual, auditory) is warranted. Copyright © 2011 John Wiley & Sons, Ltd.
Translating visions of transparency and quality development: the transformation of clinical databases in the Danish hospital field
Authors: Kousgaard Marius Brostrøm 
Published: June 2011

SUMMARYOne of the most significant developments in the quest for quality, transparency, and accountability in healthcare is the construction and the implementation of indicator‐based technologies. In Denmark, this development has been relatively pronounced, and based on an extensive document study supplemented by qualitative interviews, this paper articulates a policy history of the clinical databases for quality from the early 1990s to the present. First, the paper outlines how, in the early 1990s, the National Board of Health and representatives from the medical profession place the clinical databases on the quality agenda in healthcare. Second, the paper shows that, in spite of an initial alignment between governmental and professional interests, the establishment of national clinical databases for quality turns out to be a difficult enterprise. Third, the paper elaborates how the public authorities respond to the challenges by re‐designing the governance framework for the databases. The transformations are characterized by increased centralization, standardization, specialization and regulative pressure. Finally, it is pointed out that although the course of events does constitute an increased institutionalization of the clinical databases, large variations exist and several databases have not yet realized the ambitions of transparency and quality improvement. Copyright © 2011 John Wiley & Sons, Ltd.
Exploring effects of rainfall intensity and duration on soil erosion at the catchment scale using openLISEM: Prado catchment, SE Spain
Authors: Baartman Jantiene E.M. , Jetten Victor G. , Ritsema Coen J. , de Vente Joris 
Published: June 2011

AbstractIn semi‐arid areas, high‐intensity rainfall events are often held responsible for the main part of soil erosion. Long‐term landscape evolution models usually use average annual rainfall as input, making the evaluation of single events impossible. Event‐based soil erosion models are better suited for this purpose but cannot be used to simulate longer timescales and are usually applied to plots or small catchments. In this study, the openLISEM event‐based erosion model was applied to the medium‐sized (∼50 km2) Prado catchment in SE Spain. Our aim was to (i) test the model's performance for medium‐sized catchments, (ii) test the ability to simulate four selected typical Mediterranean rainfall events of different magnitude and (iii) explore the relative contribution of these different storms to soil erosion using scenarios of future climate variability.Results show that because of large differences in the hydrologic response between storms of different magnitudes, each event needed to be calibrated separately. The relation between rainfall event characteristics and the calibration factors might help in determining optimal calibration values if event characteristics are known. Calibration of the model features some drawbacks for large catchments due to spatial variability in Ksat values. Scenario calculations show that although ∼50% of soil erosion occurs as a result of high frequency, low‐intensity rainfall events, large‐magnitude, low‐frequency events potentially contribute significantly to total soil erosion. The results illustrate the need to incorporate temporal variability in rainfall magnitude–frequency distributions in landscape evolution models. Copyright © 2011 John Wiley & Sons, Ltd.
Oxygen binding to Arabidopsis thaliana AHb2 nonsymbiotic hemoglobin: evidence for a role in oxygen transport
Authors: Spyrakis Francesca , Bruno Stefano , Bidon‐Chanal Axel , Luque Francisco Javier , Abbruzzetti Stefania , Viappiani Cristiano , Dominici Paola , Mozzarelli Andrea 
Published: June 2011

AbstractNonsymbiotic hemoglobins AHb1 and AHb2 discovered in Arabidopsis thaliana are likely to carry out distinct physiological roles, in consideration of their differences in sequence, structure, expression pattern, and tissue localization. Despite a relatively fast autoxidation in the presence of O2, we were able to collect O2‐binding curves for AHb2 in the presence of a reduction enzymatic system. AHb2 binds O2 noncooperatively with a p50 of 0.021 ± 0.003 Torr, a value consistent with a recently proposed role in O2 transport. The analysis of the internal cavities derived from the structures sampled in molecular dynamics simulations confirms strong differences with AHb1, proposed to work as a NO deoxygenase in vivo. Overall, our results are consistent with a role for AHb2 as an oxygen carrier, as recently proposed on the basis of experiments on AHb2‐overexpressing mutants of A. thaliana. © 2011 IUBMB IUBMB Life, 63(5): 363–362, 2011.
The carbon monoxide‐releasing molecule, corm‐3 (ru(co)3cl(glycinate)), targets respiration and oxidases in campylobacter jejuni, generating hydrogen peroxide
Authors: Smith Holly , Mann Brian E. , Motterlini Roberto , Poole Robert K. 
Published: June 2011

AbstractCarbon monoxide (CO) is a classical respiratory inhibitor, but CO‐releasing molecules (CO‐RMs) have therapeutic value, increasing phagocytosis, and reducing sepsis‐induced lethality. CORM‐3, Ru(CO)3Cl(glycinate), a ruthenium‐based carbonyl that liberates CO under physiological conditions, has previously been shown to inhibit bacterial growth and respiration, even at high concentrations of oxygen. Here, we report the effects of CORM‐3 on the microaerophilic foodborne pathogen Campylobacter jejuni. Even at CO‐RM (i.e., CO) concentrations that exceed dissolved oxygen levels, CORM‐3 does not inhibit microaerobic growth. This insensitivity is not due to failure of CORM‐3 to penetrate cells, as revealed by assay with extracellular myoglobin and by the ability of CO from externally added CORM‐3 to bind intracellular membrane‐associated respiratory oxidases. Even at almost 200 μ M oxygen, CORM‐3 inhibits formate‐dependent respiration and leads to generation of hydrogen peroxide. This work shows that CO‐RMs have valuable properties as antimicrobial agents; however, growth inhibition does not always accompany inhibition of respiration, even when ambient oxygen concentrations are low. © 2011 IUBMB IUBMB Life, 63(5): 363‐371, 2011
Structural heterogeneity and ligand gating in ferric methanosarcina acetivorans protoglobin mutants
Authors: Pesce Alessandra , Tilleman Lesley , Dewilde Sylvia , Ascenzi Paolo , Coletta Massimo , Ciaccio Chiara , Bruno Stefano , Moens Luc , Bolognesi Martino , Nardini Marco 
Published: June 2011

AbstractProtoglobin from Methanosarcina acetivorans C2A (MaPgb), a strictly anaerobic methanogenic Archaea, displays peculiar structural and functional properties within members of the hemoglobin superfamily. In fact, MaPgb‐specific loops and a N‐terminal extension (20 amino acid residues) completely bury the heme within the protein matrix. Therefore, the access of diatomic gaseous molecules to the heme is granted by two apolar tunnels reaching the heme distal site from locations at the B/G and B/E helix interfaces. The presence of two tunnels within the protein matrix could be partly responsible for the slightly biphasic ligand binding behavior. Unusually, MaPgb oxygenation is favored with respect to carbonylation. Here, the crucial role of Tyr(B10)61 and Ile(G11)149 residues, located in the heme distal site and lining the protein matrix tunnels 1 and 2, respectively, on ligand binding to the heme‐Fe‐atom and on distal site structural organization is reported. In particular, tunnel 1 accessibility is modulated by a complex reorganization of the Trp(B9)60 and Phe(E11)93 side‐chains, triggered by mutations of the Tyr(B10)61 and Ile(G11)149 residues, and affected by the presence and type of the distal heme‐bound ligand. © 2011 IUBMB IUBMB Life, 63(5): 287–294, 2011
Endotoxin contamination delays the foreign body reaction
Authors: van Putten Sander M. , Wübben Maike , Plantinga Josée A. , Hennink Wim E. , van Luyn Marja J. A. , Harmsen Martin C. 
Published: June 2011

AbstractBiomaterials are at continuous risk of bacterial contamination during production and application. In vivo, bacterial contamination of biomaterials delays the foreign body reaction (FBR). Endotoxins such as lipopolysaccharides (LPS), major constituents of the bacterial cell wall, are potent stimulators of the immune system in vitro and in vivo. In vitro, biomaterials contaminated with LPS induce the production of proinflammatory cytokines by adherent macrophages. This suggests that the presence of endotoxins on biomaterials will intensify the FBR. The effects of LPS on the course of the FBR have never been studied in vivo. In this study, the influence of LPS contamination on the FBR to subcutaneously implanted Puramatrix‐loaded hexamethylenediisocyanate‐crosslinked dermal sheep collagen (HDSC) disks was studied in rats. During the onset phase of the FBR, a massive influx of granulocytes was detected in LPS‐contaminated disks, while their presence was prolonged. IL‐10 production inside LPS‐contaminated disks was increased at days 10 and 21. Macrophage densities were not affected by the presence of LPS. However, macrophage functionality was altered: giant cell formation and biomaterial degradation were delayed by LPS‐contamination up to 21 days. On the basis of these results, we conclude that LPS delays the FBR. This finding indicates that endotoxin contamination has significant implications for the in vivo function of biomaterials and medical devices and emphasizes the importance of endotoxin testing. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Guided orientation of cardiomyocytes on electrospun aligned nanofibers for cardiac tissue engineering
Authors: Kai Dan , Prabhakaran Molamma P , Jin Guorui , Ramakrishna Seeram 
Published: June 2011

AbstractCardiac tissue engineering (TE) is one of the most promising strategies to reconstruct the infarct myocardium and the major challenge involves producing a bioactive scaffold with anisotropic properties that assist in cell guidance to mimic the heart tissue. In this study, random and aligned poly(ε‐caprolactone)/gelatin (PG) composite nanofibrous scaffolds were electrospun to structurally mimic the oriented extracellular matrix (ECM). Morphological, chemical and mechanical properties of the electrospun PG nanofibers were evaluated by scanning electron microscopy (SEM), water contact angle, attenuated total reflectance Fourier transform infrared spectroscopy and tensile measurements. Results indicated that PG nanofibrous scaffolds possessed smaller fiber diameters (239 ± 37 nm for random fibers and 269 ± 33 nm for aligned fibers), increased hydrophilicity, and lower stiffness compared to electrospun PCL nanofibers. The aligned PG nanofibers showed anisotropic wetting characteristics and mechanical properties, which closely match the requirements of native cardiac anisotropy. Rabbit cardiomyocytes were cultured on electrospun random and aligned nanofibers to assess the biocompatibility of scaffolds, together with its potential for cell guidance. The SEM and immunocytochemical analysis showed that the aligned PG scaffold greatly promoted cell attachment and alignment because of the biological components and ordered topography of the scaffolds. Moreover, we concluded that the aligned PG nanofibrous scaffolds could be more promising substrates suitable for the regeneration of infarct myocardium and other cardiac defects. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Neurosteroid allopregnanolone regulates EAAC1‐mediated glutamate uptake and triggers actin changes in Schwann cells
Authors: Perego Carla , DI Cairano Eliana S. , Ballabio Marinella , Magnaghi Valerio 
Published: June 2011

AbstractRecent evidence shows that neurotransmitters (e.g., GABA, Ach, adenosine, glutamate) are active on Schwann cells, which form myelin sheaths in the peripheral nervous system under different pathophysiologic conditions. Glutamate, the most important excitatory neurotransmitter, has been recently involved in peripheral neuropathies, thus prevention of its toxic effect is desirable to preserve the integrity of peripheral nervous system and Schwann cells physiology. Removal of glutamate from the extracellular space is accomplished by the high affinity glutamate transporters, so we address our studies to analyze their functional presence in Schwann cells. We first demonstrate that Schwann cells express the EAAC1 transporter in the plasma membrane and in intracellular vesicular compartments of the endocytic recycling pathways. Uptake experiments confirm its presence and functional activity in Schwann cells. Secondly, we demonstrate that the EAAC1 activity can be modulated by exposure to the neurosteroid allopregnanolone 10 nM (a progesterone metabolite proved to support Schwann cells). Transporter up‐regulation by allopregnanolone is rapid, does not involve protein neo‐synthesis and is prevented by actin depolymerization. Allopregnanolone modulation involves GABA‐A receptor and PKC activation, promotes the exocytosis of the EAAC1 transporter from intracellular stores to the Schwann cell membrane, in actin‐rich cell tips, and modifies the morphology of cell processes. Finally, we provide evidence that glutamate transporters control the allopregnanolone‐mediated effects on cell proliferation. Our findings are the first to demonstrate the presence of a functional glutamate uptake system, which can be dynamically modulated by allopregnanolone in Schwann cells. Glutamate transporters may represent a potential therapeutic target to control Schwann cell physiology. J. Cell. Physiol. 227: 1740–1751, 2012. © 2011 Wiley Periodicals, Inc.
Human dipeptidyl peptidase III: insights into ligand binding from a combined experimental and computational approach
Authors: Tomić Antonija , Abramić Marija , Špoljarić Jasminka , Agić Dejan , Smith David M. , Tomić Sanja 
Published: June 2011

AbstractHuman dipeptidyl peptidase III (DPP III) is a zinc‐exopeptidase with implied roles in protein catabolism, pain modulation, and defense against oxidative stress. To understand the mode of ligand binding into its active site, we performed molecular modeling, site‐directed mutagenesis, and biochemical analyses. Using the recently determined crystal structure of the human DPP III we built complexes between both, the wild‐type (WT) protein and its mutant H568N with the preferred substrate Arg‐Arg‐2‐naphthylamide (RRNA) and a competitive inhibitor Tyr‐Phe‐hydroxamate (Tyr‐Phe‐NHOH). The mutation of the conserved His568, structurally equivalent to catalytically important His231 in thermolysin, to Asn, resulted in a 1300‐fold decrease of kcat for RRNA hydrolysis and in significantly lowered affinity for the inhibitor. Molecular dynamics simulations revealed the key protein–ligand interactions as well as the ligand‐induced reorganization of the binding site and its partial closure. Simultaneously, the non‐catalytic domain was observed to stretch and the opening at the wide side of the inter‐domain cleft became enhanced. The driving force for these changes was the formation of the hydrogen bond between Asp372 and the bound ligand. The structural and dynamical differences, found for the ligand binding to the WT enzyme and the H568N mutant, and the calculated binding free energies, agree well with the measured affinities. On the basis of the obtained results we suggest a possible reaction mechanism. In addition, this work provides a foundation for further site‐directed mutagenesis experiments, as well as for modeling the reaction itself. Copyright © 2010 John Wiley & Sons, Ltd.
Reassessment of the size of the supermolecular state of Dishevelled‐3
Authors: Patel Trushar R. , Winzor Donald J. 
Published: June 2011

AbstractAmendment of the interpretation of recently published size‐exclusion chromatography data for Dishevelled‐3 on Superdex 200 and Sephacryl S‐400 has led to an increase in the estimated size of the supermolecular state from 2000 to 35 000 kDa, a value that essentially duplicates the redetermined and reported estimates obtained by fluorescence correlation spectroscopy on live cells. The earlier discrepancy between the sizes of the extensively aggregated form of this scaffold protein in vivo and in vitro is thereby eliminated. Copyright © 2011 John Wiley & Sons, Ltd.
Lean strategy deployment delivers customer satisfaction at GE Healthcare
Authors: Pejsa Paul , Eng Rich 
Published: June 2011

AbstractWhen GE Healthcare combined several service divisions to form Clinical Systems Service, it faced the challenge of unifying multiple strategies while improving customer satisfaction. Focusing on the experiences of one of those segments, Monitoring Solutions/Diagnostic Cardiology, the authors show how lean strategy deployment can be used to boost customer satisfaction by improving communications and tying daily work processes to organizational objectives. © 2011 Wiley Periodicals, Inc.
Precessional forcing of tropical vegetation carbon storage
Authors: Gosling William D. , Holden Philip B. 
Published: June 2011

AbstractSince the Mid Pleistocene Revolution, which occurred about one million years ago, global temperatures have fluctuated with a quasi‐periodicity of ca. 100 ka. The pattern of past change in the extent of woodlands, and therefore by inference vegetation carbon storage, has been demonstrated to have a strong positive link with this global temperature change at high and mid latitudes. However, understanding of climate systems and ecosystem function indicates that the pattern of woodland change at low latitudes may follow a fundamentally different pattern. We present output from the intermediate complexity model GENIE‐1, comprising a single transient simulation over the last 800 ka and a 174‐member ensemble of 130 ka transient simulations over the last glacial cycle. These simulations suggest that while vegetation carbon storage in mid–high northern latitudes robustly follows the characteristic ca. 100 ka cycle, this signal is not a robust feature of tropical vegetation, which is subject to stronger direct forcing by the precessional (21 ka) orbital cycle (albeit with a highly uncertain response). We conclude that the correlation of palaeoenvironmental records from low latitudes with global temperature change must be done with caution. Copyright © 2011 John Wiley & Sons, Ltd.