bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of oxygen transfer in stented arteries and correlation with in‐stent restenosis
Authors: Caputo M. , Chiastra C. , Cianciolo C. , Cutrì E. , Dubini G. , Gunn J. , Keller B. , Migliavacca F. , Zunino P. 
Published: August 2013

SUMMARYComputational models are used to study the combined effect of biomechanical and biochemical factors on coronary in‐stent restenosis, which is a postoperative remodeling and regrowth pathology of the stented arteries. More precisely, we address numerical simulations, on the basis of Navier–Stokes and mass transport equations, to study the role of perturbed wall shear stresses and reduced oxygen concentration in a geometrical model reconstructed from a real porcine artery treated with a stent. Joining in vivo and in silico tools of investigation has multiple benefits in this case. On one hand, the geometry of the arterial wall and of the stent closely correspond to a real implanted configuration. On the other hand, the inspection of histological tissue samples informs us on the location and intensity of in‐stent restenosis. As a result, we are able to correlate geometrical factors, such as the axial variation of the artery diameter and its curvature; the numerical quantification of biochemical stimuli, such as wall shear stresses; and the availability of oxygen to the inner layers of the artery, with the appearance of in‐stent restenosis. This study shows that the perturbation of the vessel curvature could induce hemodynamic conditions that stimulate undesired arterial remodeling. Copyright © 2013 John Wiley & Sons, Ltd.
Computational modeling of human head under blast in confined and open spaces: primary blast injury
Authors: Rezaei A. , Salimi Jazi M. , Karami G. 
Published: August 2013

SUMMARYIn this paper, a computational modeling for biomechanical analysis of primary blast injuries is presented. The responses of the brain in terms of mechanical parameters under different blast spaces including open, semi‐confined, and confined environments are studied. In the study, the effect of direct and indirect blast waves from the neighboring walls in the confined environments will be taken into consideration. A 50th percentile finite element head model is exposed to blast waves of different intensities. In the open space, the head experiences a sudden intracranial pressure (ICP) change, which vanishes in a matter of a few milliseconds. The situation is similar in semi‐confined space, but in the confined space, the reflections from the walls will create a number of subsequent peaks in ICP with a longer duration. The analysis procedure is based on a simultaneous interaction simulation of the deformable head and its components with the blast wave propagations. It is concluded that compared with the open and semi‐confined space settings, the walls in the confined space scenario enhance the risk of primary blast injuries considerably because of indirect blast waves transferring a larger amount of damaging energy to the head. Copyright © 2013 John Wiley & Sons, Ltd.
On the distributed orchestration of stochastic discrete event simulations
Authors: Sui Zhiquan , Harvey Neil , Pallickara Shrideep 
Published: August 2013

SUMMARYDiscrete event simulations are a powerful technique for modeling stochastic systems with multiple components where interactions between these components are governed by the probability distribution functions associated with them. Complex discrete event simulations are often computationally intensive with long completion times. This paper describes our solution to the problem of orchestrating the execution of a stochastic, discrete event simulation where computational hot spots evolve spatially over time. Our performance benchmarks report on our ability to balance computational loads in these settings. Copyright © 2013 John Wiley & Sons, Ltd.
Dynamic task assignment and resource management in cloud services by using bargaining solution
Authors: Shin Kwang Sup , Park Myoung‐Ju , Jung Jae‐Yoon 
Published: August 2013

SUMMARYCloud computing provides infrastructure, platform and software as services to customers. For the purpose of providing reliable and truthful service, a fair and elastic resource allocation strategy is essential from the standpoint of service customers. In this paper, we propose a game theoretic mechanism for dynamic cloud service management, including task assignment and resource allocation to provide reliable and truthful cloud services. A user utility function is first devised considering the dynamic characteristics of cloud computing. The elementary stepwise system is then applied to efficiently assign tasks to cloud servers. A resource allocation mechanism based on bargaining game solution is also adopted for fair resource allocation in terms of quality of service of requested tasks. Through numerical experiments, it is shown that the proposed mechanism guarantees better system performance than several existing methods. The experimental results show that the mechanism completes the requested tasks earlier with relatively higher utility while providing a significant level of fairness compared with existing ones. The proposed mechanism is expected to support cloud service providers in elastically managing their limited resources in a cloud computing environment in terms of quality of service. Copyright © 2013 John Wiley & Sons, Ltd.
Modification of Marx generator with a doubling of output voltage
Authors: Tatur Valery V. 
Published: August 2013

SummaryA multistage generator of high‐voltage pulses with a doubling of output voltage built according to the Marx scheme is presented. A specific feature of the generator circuit design is the substitution of charging diodes for charging resistors and connection of the supplying voltage through an inductor. Such a design makes it possible to double the amplitude of pulses across a load, which is proportional to the number of connected stages, and to minimize the power loss during the charging of storage capacitors. Copyright © 2013 John Wiley & Sons, Ltd.
Effects of structural connectivity on fine scale population genetic structure of muskrat, Ondatra zibethicus
Authors: Laurence Sophie , Smith Matthew J. , Schulte‐Hostedde Albrecht I. 
Published: August 2013

AbstractIn heterogeneous landscapes, physical barriers and loss of structural connectivity have been shown to reduce gene flow and therefore lead to population structuring. In this study, we assessed the influence of landscape features on population genetic structure and gene flow of a semiaquatic species, the muskrat. A total of 97 muskrats were sampled from three watersheds near Sudbury, Ontario, Canada. We estimated population genetic structure using 11 microsatellite loci and identified a single genetic cluster and no genetic differences were found among the watersheds as a result of high levels of gene flow. At finer scales, we assessed the correlation between individual pairwise genetic distances and Euclidean distance as well as different models of least cost path (LCP). We used a range of cost values for the landscape types in order to build our LCP models. We found a positive relationship between genetic distance and least cost distance when we considered roads as corridors for movements. Open landscapes and urban areas seemed to restrict but not prevent gene flow within the study area. Our study underlines the high‐dispersal ability of generalist species in their use of landscape and highlights how landscape features often considered barriers to animal movements are corridors for other species.
Mechanistic Approaches to Molecular Catalysts for Water Oxidation
Authors: Kikuchi Takashi , Tanaka Koji 
Published: August 2013

AbstractWater oxidation, in which two water molecules undergo the coupled loss of four electrons and four protons to form an O–O bond, is one of the most appealing target reactions for molecular catalysts in view of hydrogen production by electrolytic or photolytic water splitting to cope with urgent energy and environmental problems. Inspired by a natural oxygen‐evolving multinuclear manganese cluster, a number of water oxidation catalysts based on multinuclear transition‐metal complexes have been developed over the last three decades. In recent years, in parallel with the discovery of mononuclear oxygen‐evolving complexes, both experimental and theoretical studies have yielded important insight into O–O bond‐formation pathways in these water‐oxidizing complexes. In this microreview, we will present an updated view of selected current literature focusing on the working mechanism of ruthenium‐based water oxidation catalysts and on the development of rationally designed ruthenium complexes that activate water at mild potentials.
Catalytic Staudinger/Aza‐Wittig Sequence by in situ Phosphane Oxide Reduction
Authors: van Kalkeren Henri A. , te Grotenhuis Colet , Haasjes Frank S. , Hommersom C. (Rianne) A. , Rutjes Floris P. J. T. , van Delft Floris L. 
Published: August 2013

AbstractA Staudinger/aza‐Wittig reaction sequence is described that is catalytic in phosphorus. Towards this end, the phosphane oxide is reduced in situ by diphenylsilane, which allows for substoichiometric amounts of the catalyst 5‐phenyldibenzophosphole to be used. The substrate scope is investigated and benzoxazoles, benzodiazepine imidates and a 2‐methoxypyrrole were successfully synthesized. These investigations show that a fast aza‐Wittig reaction is required to obtain high yields.
Multi‐size‐mesh multi‐time‐step algorithm for noise computation on curvilinear meshes
Authors: Le Garrec T. , Gloerfelt X. , Corre C. 
Published: August 2013

SUMMARYAeroacoustic problems are often multi‐scale and a zonal refinement technique is thus desirable to reduce computational effort while preserving low dissipation and low dispersion errors from the numerical scheme. For that purpose, the multi‐size‐mesh multi‐time‐step algorithm of Tam and Kurbatskii [AIAA Journal, 2000, 38(8), p. 1331–1339] allows changes by a factor of two between adjacent blocks, accompanied by a doubling in the time step. This local time stepping avoids wasting calculation time, which would result from imposing a unique time step dictated by the smallest grid size for explicit time marching. In the present study, the multi‐size‐mesh multi‐time‐step method is extended to general curvilinear grids by using a suitable coordinate transformation and by performing the necessary interpolations directly in the physical space due to multidimensional interpolations combining order constraints and optimization in the wave number space. A particular attention is paid to the properties of the Adams–Bashforth schemes used for time marching. The optimization of the coefficients by minimizing an error in the wave number space rather than satisfying a formal order is shown to be inefficient for Adams–Bashforth schemes. The accuracy of the extended multi‐size‐mesh multi‐time‐step algorithm is first demonstrated for acoustic propagation on a sinusoidal grid and for a computation of laminar trailing edge noise. In the latter test‐case, the mesh doubling is close to the airfoil and the vortical structures are crossing the doubling interface without affecting the quality of the radiated field. The applicability of the algorithm in three dimensions is eventually demonstrated by computing tonal noise from a moderate Reynolds number flow over an airfoil. Copyright © 2013 John Wiley & Sons, Ltd.
Graphene for improved femtosecond laser based pluripotent stem cell transfection
Authors: Mthunzi Patience , He Kuang , Ngcobo Sandile , Khanyile Thulile , Warner Jamie H. 
Published: August 2013

AbstractPluripotent stem cells are hugely attractive in the tissue engineering research field as they can self‐renew and be selectively differentiated into various cell types. For stem cell and tissue engineering research it is important to develop new, biocompatible scaffold materials and graphene has emerged as a promising material in this area as it does not compromise cell proliferation and accelerates specific cell differentiation. Previous studies have shown a non‐invasive optical technique for mouse embryonic stem (mES) cell differentiation and transfection using femtosecond (fs) laser pulses. To investigate cellular responses to the influence of graphene and laser irradiation, here we present for the first time a study of mES cell fs laser transfection on graphene coated substrates. First we studied the impact of graphene on Chinese Hamster Ovary (CHO‐K1) cell viability and cell cytotoxicity in the absence of laser exposure. These were tested via evaluating the mitochondrial activity through adenosine triphosphates (ATP) luminescence and breakages on the cell plasma membrane assessed using cytosolic lactate dehydrogenase (LDH) screening. Secondly, the effects of fs laser irradiation on cell viability and cytotoxicity at 1064 and 532 nm for cells plated and grown on graphene and pure glass were assessed. Finally, optical transfection of CHO‐K1 and mES cells was performed on graphene coated versus plain glass substrates. Our results show graphene stimulated cell viability whilst triggering a mild release of intracellular LDH. We also observed that compared to pure glass substrates; laser irradiation at 1064 nm on graphene plates was less cytotoxic. Finally, in mES cells efficient optical transfection at 1064 (82%) and 532 (25%) nm was obtained due to the presence of a graphene support as compared to pristine glass. Here we hypothesize an up‐regulation of cell adhesion promoting peptides or laminin‐related receptors of the extracellular matrix (ECM) in cell samples grown and irradiated on graphene substrates. By bringing together advances in optics and nanomaterial sciences we demonstrate pathways for enhancement of pluripotent stem cell biology. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Differential Activation of Signaling Pathways by Low‐Osmolar and Iso‐Osmolar Radiocontrast Agents in Human Renal Tubular Cells
Authors: Andreucci Michele , Faga Teresa , Russo Domenico , Bertucci Bernardo , Tamburrini Oscar , Pisani Antonio , Sabbatini Massimo , Fuiano Giorgio , Michael Ashour 
Published: August 2013

ABSTRACTRadiocontrast media (RCM)‐induced nephrotoxicity (CIN) is a major clinical problem accounting for 12% of all hospital‐acquired cases of acute kidney injury (AKI). The pathophysiology of AKI due to RCM is not well understood, but direct toxic effects on renal cells have been postulated as contributing to CIN. It is believed that iso‐osmolar RCM (IOCM) are less nephrotoxic than low‐osmolar RCM (LOCM) but clinical data have been controversial. We have investigated the intracellular signaling pathways that may be affected by the LOCM iomeprol (IOM) and the IOCM iodixanol (IOD). Both IOM and IOD caused a dramatic decrease in phosphorylation of the kinase Akt at Ser473 and Thr308 in human renal tubular (HK‐2) cells, with IOM having a greater effect; IOM also caused a greater decrease in cell viability. IOM also had a greater effect on phosphorylation of p38 MAP kinases, JNKs, and NF‐kB (Ser276), and caused a marked decrease in the phosphorylation of forkhead box O3a (FOXO3a) and signal transducer and activator of transcription 3 (STAT3). However, IOD caused a greater decrease in the phosphorylation of mTOR (Ser2448) and phospho‐ERK 1/2 while both RCM caused a similar decrease in the phosphorylation of phospho‐p70S6 kinase (Ser371). In vivo studies showed that both IOM and IOD caused a significant decrease in both pAkt (Ser473) and pERK 1/2 in rat kidneys. Our study gives an insight into the possible mechanism of toxicity of RCM via their action on intracellular signaling pathways and may help in developing pharmacological interventions for their side‐effects. J. Cell. Biochem. 115: 281–289, 2014. © 2013 Wiley Periodicals, Inc.
Environmentally Sustainable and Chemo‐selectively Favorable Synthesis of Substituted 2H‐Pyran‐2‐ones in Water under MWI
Authors: Cui Liang‐Yan , Wang Xin , He Yan , Fan Xue‐Sen 
Published: August 2013

AbstractIn this paper, a novel synthesis of diversely substituted 2H‐pyran‐2‐ones via the tandem reaction of 3‐hydroxyhexa‐4,5‐allenic esters in water under the promotion of MWI has been developed. Compared with those reactions carried out in organic solvents, water mediated synthesis of poly‐substituted 2H‐pyran‐2‐ones is not only environmentally sustainable, but also chemo‐selectively favorable.
Comparative Study of Surface Functionalization of Hydroxyapatite by One‐pot Grafting of Organophosphonates Species
Authors: Saoiabi Sanaa , Laghzizil Abdelaziz , El‐Hammari Larbi , Saoiabi Ahmed 
Published: August 2013

AbstractThe ability to graft apatite surface by specific ligand fields creates powerful new technology applications. Thus, grafted organophosphonate can provide an effective route to modify the surface properties of apatite materials. The ability to decorate the apatite surface with the desired functionality requires covalent attachment to solid interface; most commonly achieved using organophosphonate self‐assembly. The current study shows that various phosphonates can react with calcium ions and control the formation of the porous apatite with high surface areas as well as the porosity. The structural and surface properties are given some importance in this review.
Nickel Complexes Catalyzed Hydrodechlorination of Aryl Chlorides in Ionic Liquid
Authors: Sun Guanghui , Zhang Lirong , Zhang Guanlin , Fan Yuehui , Wang Yuhong , Lu Guanzhong 
Published: August 2013

AbstractThe hydrodechlorination performance of nickel complex catalysts, Ni[phen]2(PF6)2 and Ni[bpy]3(PF6)2, were investigated with [Bmim]Br as the ionic liquid solvent. It is proved that Ni[phen]2(PF6)2 is efficient for the hydrodechlorination of aryl chlorides under mild conditions with water as the hydrogen source. The hydrogen source of reaction is from the water which was confirmed by the deuterium incorporation experiments. Recycling experiments showed a decreasing activity of this catalyst due to a small leaching of nickel complex from the ionic liquid phase during the recycling process where n‐heptane was used as the extractant. A plausible reaction route has been suggested.
Piezoelectric Quartz Crystal Anti‐Protein Immunosensors Based on Immobilized Fullerene C60‐Proteins
Authors: Liao Yao‐Hsuan , Shih Jeng‐Shong 
Published: August 2013

AbstractVarious fullerene C60‐proteins such as C60‐myoglobin (C60‐Mb), C60‐hemoglobin (C60‐Hb) and C60‐gliadin, coated piezoelectric quartz crystals were prepared and applied in piezoelectric quartz crystal immunosensors for protein‐antibodies such as anti‐myoglobin (Anti‐Mb), anti‐hemoglobin (Anti‐Hb) and anti‐gliadin respectively. The immobilizations of myoglobin, hemoglobin and gliadin onto Fullerene C60 were studied with a C60‐coated piezoelectric crystal detection system, respectively. The partially irreversible frequency responses for theses proteins were observed by a desorption study, implying that C60 can strongly adsorb these proteins. Thus, immobilized C60‐Mb, C60‐Hb and C60‐gliadin coating materials were successfully prepared and identified with FTIR spectrometry. The C60‐Mb, C60‐Hb and C60‐gliadin coated piezoelectric (PZ) quartz crystal immunosensors with homemade computer interfaces for signal acquisition and data processing were developed and applied for detection of Anti‐Mb, Anti‐Hb and anti‐gliadin respectively. The C60‐protein coated PZ immunosensors for Anti‐Mb, Anti‐Hb and antigliadin exhibited linear frequency responses to the concentrations of theses anti‐proteins with sensitivities of 1.43 × 103, 2.59 × 103 and 8.05 × 103 Hz/(mg/mL) respectively. The detection limits of these PZ‐immunosensors were 4.36 × 10−3, 3.23 × 10−3 and 1.98 × 10−3 mg/mL for Anti‐Mb, Anti‐Hb and anti‐gliadin respectively. Effects of pH and temperature on the frequency responses of the anti‐protein PZ‐immunosensors were also investigated. The optimum pH of these anti‐proteins and the optimum temperature for the PZ‐immunosensors were observed at pH = 7 and around 30 °C respectively. The interferences of various common species in human blood, e.g., cysteine, tyrosine, urea, glucose, ascorbic acid and metal ions, to these anti‐protein PZ‐immunosensors were also investigated respectively. These species showed nearly no interference or quite small interference with the anti‐protein PZ‐immunosensors. The reproducibility and lifetime of these immobilized C60‐protein coated PZ crystal immunosensors were also investigated and discussed.
Self‐assembly of Carbon Particles as a Heat Sink Coating to Promote Radiative Cooling
Authors: Hsin Yu Lin , Chang Chih Kuang , Wang Mei Hua , Yeh Hsiao‐Chun , Su Ting‐Yao 
Published: August 2013

AbstractNovel composite carbon particles are developed that can self‐assemble as a coating on a substrate without a binder. These carbon particles were used as a coating to enhance thermal dissipation and their thermal conductivity, surface emissivity and cooling performance were measured. Carbon particles with both thiol and epoxy functional groups self‐assembled to form a coating on the surface of a heat sink without a binder, which greatly improved the thermal conductivity of the coating. Coating a heat sink with the carbon particles yielded a higher thermal conductivity and emissivity than could be obtained with the addition of binder in the conventional approach, and significantly enhanced the cooling performance. In addition, the cooling performance of the carbon nanotube outperformed all other particles when coated on a substrate, because it had the highest thermal conductivity and good radiation emissivity. We developed an equation to describe the various parameters affecting the cooling performance of the thermally dissipative coating. This equation was confirmed by the experimental data.
Electrocatalytic Oxidation of Hydrogen Peroxide at a Sol‐gel Derived Carbon Ceramic Electrode Modified with Copper Iodide
Authors: Karim‐Nezhad Ghasem , Pashazadeh Sara , Pashazadeh Ali 
Published: August 2013

AbstractA novel modified carbon ceramic electrode using CuI as modifier was fabricated. The copper iodide modified sol‐gel derived carbon ceramic (CIM‐SGD‐CC) electrode has high catalytic ability for electrooxidation of hydrogen peroxide. The charge transfer coefficient (α) and exchange current density (j0) for the modified electrode were calculated. It has been shown that using the CIM‐SGD‐CC electrode, hydrogen peroxide can be determined by cyclic voltammetry and amperometry with limit of detections 26 and 0.31 μmol L−1, respectively. The advantages of the modified CCE are its good stability and reproducibility of surface renewal by simple polishing, excellent catalytic activity.
Advances in Carbon‐Incorporated Non‐Noble Transition Metal Catalysts for Oxygen Reduction Reaction in Polymer Electrolyte Fuel Cells
Authors: Hung Tai‐Feng , Chen Syuan‐Hong , Tu Meng‐Hsiu , Lu Zhi‐Hsiang , Chen Chih Kai , Liu Ru‐Shi , Greer Heather F. , Zhou Wuzong , Lo Man‐Yin 
Published: August 2013

AbstractConsiderable efforts have been exerted in the development of non‐noble metal catalysts (NNMCs) for oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs). The effects of the preparation strategy, including carbon support, metal and nitrogen precursors, as well as heat‐treatment conditions, on the ORR activity for such NNMCs have also been extensively explored. In this review, we mainly focused on the recent advances in carbon‐incorporated NNMCs, specifically carbon‐incorporated iron nitride (FeCN)‐based catalysts. Influences of pyrolysis temperature on the crystalline and local structures, chemical environment, morphology, and ORR activity of FeCN‐based catalysts were discussed, and the ORR mechanism was also proposed.