bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toll‐like receptors and aseptic loosening of hip endoprosthesis—a potential to respond against danger signals?
Authors: Lähdeoja Tuomas , Pajarinen Jukka , Kouri Vesa‐Petteri , Sillat Tarvo , Salo Jari , Konttinen Yrjö T. 
Published: September 2009

AbstractBacterial remnants and subclinical biofilms residing on prosthesis surfaces have been speculated to play a role in hip implant loosening by opsonizing otherwise relatively inert wear particles. The innate immune system recognizes these microbial pathogen‐associated molecular patterns (PAMPs) using Toll‐like receptors (TLRs). Our objective was to evaluate the possible presence of TLRs in aseptic synovial membrane‐like interface tissue. Bacterial culture‐negative, aseptic (n = 4) periprosthetic synovial membrane‐like tissue was compared to osteoarthritis synovial membrane (n = 5) for the presence of cells positive for all known human functional TLRs, stained using specific antibodies by immunohistochemistry, and evaluated using morphometry. In comparison to osteoarthtritic synovium, the number of TLR‐positive cells was found to be increased in the aseptic setting, reflecting the considerable macrophage infiltration to the tissues investigated. Thus aseptic periprosthetic tissue seems to be very reactive to PAMPs. It has been recently recognized that TLR do not only respond to traditional PAMPs, but also to endogenous alarmings or danger signals released from necrotic and activated cells. Alarming‐TLR interaction in the periprosthetic tissue might be a novel mechanism of aseptic loosening of endoprosthesis. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:184–190, 2010
GDF‐5/7 and bFGF activate integrin α2‐mediated cellular migration in rabbit ligament fibroblasts
Authors: Date Hirokazu , Furumatsu Takayuki , Sakoma Yoshimasa , Yoshida Aki , Hayashi Yuko , Abe Nobuhiro , Ozaki Toshifumi 
Published: September 2009

AbstractCellular activities responding to growth factors are important in ligament healing. The anterior cruciate ligament (ACL) has poor healing potential compared to the medial collateral ligament (MCL). To assess the differences, we investigated the proliferation, migration, adhesion, and matrix synthesis responding to growth factors in rabbit ACL and MCL fibroblasts. ACL cell proliferation to basic fibroblast growth factor (bFGF), bone morphogenetic protein‐2, growth and differentiation factor (GDF)‐5, and GDF‐7 treatment was similar to that of MCL cells. GDF‐5 enhanced Col1a1 expression in ACL and MCL fibroblasts up to 4.7‐ and 17‐fold levels of control, respectively. MCL fibroblasts showed stronger migration activities in response to bFGF and GDF‐5 than ACL cells. GDF‐5/7 and bFGF also changed the stress fiber formation and cellular adhesion by modulating the distribution of integrin α2. Functional blocking analyses using anti‐integrin α2 antibodies revealed that cellular migration responding to growth factors depended on the integrin α2‐mediated adhesion on type I collagen. The expression of integrin α2 was also increased by growth factors in both cells. Our results demonstrate that GDF‐5/7 and bFGF stimulate cellular migration by modulating integrin α2 expression and integrin α2‐dependent adhesion, especially in MCL fibroblasts. These findings suggest that the different healing potential between ACL and MCL may be caused by different cellular behavior in the integrin α2‐mediated cellular migration in response to growth factors. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:225–231, 2010
Inhibition of ectopic bone formation by a selective retinoic acid receptor α‐agonist: A new therapy for heterotopic ossification?
Authors: Shimono Kengo , Morrison Tiffany N. , Tung Wei‐en , Chandraratna Roshantha A. , Williams Julie A. , Iwamoto Masahiro , Pacifici Maurizio 
Published: September 2009

AbstractHeterotopic ossification (HO) consists of formation of ectopic cartilage followed by endochondral bone and is triggered by major surgeries, large wounds, and other conditions. Current therapies, including low‐dose irradiation, are not always effective and do not target the skeletogenic process directly. Because chondrogenesis requires a decrease of nuclear retinoic acid receptor α (RARα) action, we reasoned that pharmacologic activation of this receptor pathway should inhibit HO. Thus, we selected the synthetic retinoid NRX195183, a potent and highly selective RARα‐agonist, and found that it did inhibit chondrogenesis in mouse limb micromass cultures. We established a mouse HO model consisting of subcutaneous implantation of Matrigel mixed with rhBMP‐2. Control mice receiving daily oral doses of vehicle (peanut oil) or retinol (a natural nonactive retinoid precursor) developed large HO‐like masses by days 9–12 that displayed abundant cartilage, endochondral bone, vessels, and marrow. In contrast, formation of HO‐like masses was markedly reduced in companion mice receiving daily oral doses of α‐agonist. These ectopic masses contained sharply reduced amounts of cartilage and bone, blood vessels, and TRAP‐positive osteoclasts, and expressed markedly lower levels of master chondrogenic genes including Sox9, cartilage genes such as collagen XI and X, and osteogenic genes including Runx2. The data provide proof‐of‐principle evidence that a pharmacological strategy involving a selective RARα‐agonist can indeed counteract an ectopic skeletal‐formation process effectively and efficiently, and could thus represent a novel preventive treatment for HO. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:271–277, 2010
Parabolic mirror‐assisted tip‐enhanced spectroscopic imaging for non‐transparent materials
Authors: Zhang Dai , Wang Xiao , Braun Kai , Egelhaaf Hans‐Joachim , Fleischer Monika , Hennemann Laura , Hintz Holger , Stanciu Catrinel , Brabec Christoph J. , Kern Dieter P. , Meixner Alfred J. 
Published: September 2009

AbstractA versatile and efficient tip‐enhanced spectroscopic imaging technique based on a parabolic mirror (PM) assisted near‐field optical microscope is demonstrated. The replacement of the conventional objective lens with a parabolic mirror allows the non‐restricted investigation of sample materials regarding their opacity. In addition, an improved signal collection efficiency and effective excitation of the longitudinal plasmonic oscillation in the tip apex are obtained. The capabilities of PM‐assisted tip‐enhanced Raman (TER) and photoluminescence (PL) imaging in distinguishing the individual domains made of different chemical components in poly (3‐hexythiophene)/[6, 6]‐penyl‐C61 butyric acid methyl ester (P3HT/PCBM) solar cell blend film and in the investigation of the plasmonic properties of geometrically well‐defined Au cones are demonstrated. Copyright © 2009 John Wiley & Sons, Ltd.
A pigment (CuS) identified by micro‐Raman spectroscopy on a Chinese funerary lacquer ware of West Han Dynasty
Authors: Jin Pu‐Jun , Yao Zheng‐Quan , Zhang Mao‐Lin , Li Yu‐Hu , Xing Hui‐Ping 
Published: September 2009

AbstractA blue pigment was identified by micro‐Raman spectroscopy, X‐ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM)/energy dispersive X‐ray (EDX) and X‐ray diffraction (XRD). The test sample, a funerary lacquer tray, belongs to West Han Dynasty (206 BC–AD 8) of China and was decorated with faint blue patterns. The result from Raman spectroscopy showed that the faint blue is covellite (CuS) due to the presence of a characteristic peak at 474.5 cm−1, which further was confirmed by XRF, SEM–EDX and XRD. This research indicated that CuS had been used as a blue pigment to decorate lacquer wares from the West Han Dynasty in China. Copyright © 2009 John Wiley & Sons, Ltd.
Tip‐enhanced Raman spectroscopy of 6H‐SiC with graphene adlayers: selective suppression of E1 modes
Authors: Domke Katrin F. , Pettinger Bruno 
Published: September 2009

AbstractWe have characterized 6H‐SiC substrates with tip‐enhanced Raman spectroscopy in a broad spectral range between 100 and 3000 cm−1. A few adlayers of graphene previously grown on the semiconductor's C surface enabled us to approach the Au tip of a scanning tunneling microscope (STM) into tunnelling contact. In the recorded STM images of the substrate, we discern the height of the carbon adlayers in different sample regions. We compare tip‐enhanced Raman (TER) spectra of the sample to normal Raman spectra recorded with the field vector of the linearly polarized light oriented at 30° or 90° with respect to the surface normal. All spectra show the phonon fingerprint of SiC and of graphene. We find the E1 modes of 6H‐SiC selectively suppressed in the TER spectra whereas they are present in the normal Raman spectra excited at 30°. This effect is explained by a tip‐induced symmetry change. Copyright © 2009 John Wiley & Sons, Ltd.
Assessment of polymer composites for hydrodynamic journal‐bearing applications
Authors: McCarthy D. M. C. , Glavatskih S. B. 
Published: September 2009

AbstractPolymer composites are used as facing materials in hydrodynamic bearings for their low friction and ‘compliant’ properties, which play an important role during machinery operation. In journal bearings, this low friction property can be of significant importance during start and stop cycles when insufficient oil is available to fully separate the surfaces in relative motion. Current work is aimed at determining a suitable material for use in hydrodynamic journal bearings for applications in hydroelectric power plants. This study investigates friction and wear encountered during the transition from the stationary state to operational speed (acceleration) during initial start‐up. This is examined for virgin poly‐tetra‐fluoro‐ethylene (PTFE) together with a series of commercially available PTFE‐based composites and a babbitt material in boundary/mixed lubrication conditions. Tests are performed using standard laboratory block‐on‐ring test apparatus with a VG32 mineral oil. Copyright © 2009 John Wiley & Sons, Ltd.
Syntheses of Polyesters from Succinic Anhydride and Various Diols Catalyzed by Metal Triflates
Authors: Yashiro Takao , Kricheldorf Hans R. , Huijser Saskia 
Published: September 2009

AbstractSuccinic anhydride (SuAh) was polymerized with various α,ω‐alkanediols from 1,3‐propanediol up to 1,10‐decanediol. Most polycondensations were conducted in bulk at temperatures of 80 °C with bismuth triflate as catalyst and number average molecular weights ($\overline M _{\rm n} {\rm s}$, uncorrected SEC data) up to 35 000 Da were obtained. Polycondensations of SuAh with 1,6‐hexanediol were also catalyzed with aluminum, tin(II), scandium, lanthanium, samarium, and hafnium triflate. Whereas, poor results were achieved with La‐triflate, aluminum and tin(II) triflate yielded $\overline M _{\rm n} {\rm s}$ comparable to those obtained with Bi‐triflate. With exception of the basic lanthanum triflate, all other catalysts generated small amounts of ether groups. The MALDI‐TOF mass spectra proved that the molecular weights depended on the conversion and on the extent of cyclization. The polycondensations of 1,4‐butanediol at temperatures up to 120 °C were affected by the formation of tetrahydrofuran, and even with an excess of the diol $\overline M _{\rm n} {\rm s}$ <10 000 Da were not obtained. Yet, BiCl3 and Bi‐triflate catalyzed polycondensations in refluxing decalin gave satisfactory results ($\overline M _{\rm n} {\rm s}$ ≈ 30 000 Da, uncorrected SEC data).magnified image
Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization with a Polymeric RAFT Agent Containing Multiple Trithiocarbonate Groups
Authors: Liu Yuqing , Cavicchi Kevin A. 
Published: September 2009

AbstractPolytrithiocarbonates were prepared by the condensation polymerization of a dicarboxylic acid functional trithiocarbonate and a diol. These polymers were effective reversible addition fragmentation chain transfer (RAFT) agents for the bulk polymerization of polystyrene homopolymers and a poly[styrene‐block‐(tert‐butylstyrene)] block copolymer. Size exclusion chromatography (SEC) analysis of the original and amine cleaved polymers showed that the polydispersity of the polymer tended toward two with increasing polymerization time, but the polydispersity of the polymer units between trithiocarbonate groups was narrow (ca. 1.1–1.3) Also, the average number of trithiocarbonate groups per chain was found to be proportional to the number of trithiocarbonate groups in the starting RAFT agent. These polytrithiocarbonate RAFT agents will be useful for preparing multiblock copolymers over a range of chemistries, block numbers and molecular weights.magnified image
Micellization Phenomena in Semicrystalline Block Copolymers: Reflexive and Critical Views on the Formation of Cylindrical Micelles
Authors: Lazzari Massimo , López‐Quintela M. Arturo 
Published: September 2009

AbstractInvestigations on the self‐assembly of block copolymers in solution have in some way a less well‐studied history than the study of their phase separation in the solid state, and many aspects are yet not completely understood. Here we focus on the behavior of a specific class of copolymers, namely semicrystalline block copolymers, capable of forming cylindrical aggregates in a solvent selective for the non‐crystalline, complementary block. A common model of micellization is proposed, in principle applicable to most of these copolymeric systems.magnified image
A Main‐Chain de Vries Smectic Liquid Crystal Polymer Prepared by Hoveyda–Grubbs Catalyst Initiated Acyclic Diene Metathesis Polymerization
Authors: Walba David M. , Yang Hong , Keller Patrick , Zhu Chenhui , Shao Renfan , Coleman David A. , Jones Christopher D. , Clark Noel A. 
Published: September 2009

AbstractA main‐chain liquid crystalline polymer has been obtained by applying a Hoveyda–Grubbs 2nd generation catalyst in acyclic diene metathesis polymerization (ADMET) of a monomer containing on one end a terminal dimethylvinylsilyl group and at the other end a terminal CC double bond. This material showed an interesting Iso‐de Vries SmA* – SmC* – Glass phase transition with a very small layer shrinkage on progressing from the SmA* phase into the SmC* phase. Will this material present a helical structure along the fiber axis in the SmC* temperature range? Several physical characterization methods including XRD, optical observation, and microtome technique have been used to investigate the internal structural organization in this liquid crystalline fiber.magnified image
Highly Active Syndiospecific Living Polymerization of Higher 1‐Alkene with ansa‐Fluorenylamidodimethyltitanium Complex
Authors: Cai Zhengguo , Ohmagari Masayoshi , Nakayama Yuushou , Shiono Takeshi 
Published: September 2009

Abstract1‐Hexene polymerization was conducted by [t‐BuNSiMe2(3,6‐t‐Bu2Flu)]TiMe2 (1) using trialkylaluminum‐free modified methylaluminoxane (dMMAO) as a cocatalyst in toluene. The system produced living syndiotactic poly(1‐hexene) with high turnover frequency of propagation (TOF, 98 s−1) at 0 °C. The propagation rate was increased linearly against the 1‐hexene concentration, which indicates that the first‐order dependence of the propagation rate on monomer concentration. Polymerizations of 1‐octene, 1‐decene and 1‐dodecene were also conducted for investigating the effect of chain length of 1‐alkene on propagation rate by means of the livingness of this system. The propagation rate decreased according to the chain length until 1‐decene but almost unchanged in longer 1‐alkene: TOF, 1‐octene (62 s−1)>1‐decene (32 s−1) ≈ 1‐dodecene (31 s−1).magnified image
Intrinsic mono‐component decomposition of functions: An advance of Fourier theory
Authors: Qian Tao 
Published: September 2009

AbstractWe propose a function decomposition model, called intrinsic mono‐component decomposition (IMD). It is a continuation of the recent study on adaptive decomposition of functions into mono‐components (MCs). It is a further improvement of two recent results of which one is adaptive decomposition of functions into modified inner functions, and the other is decomposition by using adaptive Takenaka‐Malmquist systems. The proposed new decomposition model is of less restriction and thus gains more adaptivity. The theory is valid to both the unit circle and the real line contexts. Copyright © 2009 John Wiley & Sons, Ltd.
Mechanical and transport constitutive models for fractures subject to dissolution and precipitation
Authors: Elsworth Derek , Yasuhara Hideaki 
Published: September 2009

AbstractTransient changes in the permeability of fractures in systems driven far‐from‐equilibrium are described in terms of proxy roles of stress, temperature and chemistry. The combined effects of stress and temperature are accommodated in the response of asperity bridges where mineral mass is mobilized from the bridge to the surrounding fluid. Mass balance within the fluid accommodates mineral mass either removed from the flow system by precipitation or advection, or augmented by either dissolution or advection. Where the system is hydraulically closed and initially at equilibrium, reduction in aperture driven by the effects of applied stresses and temperatures will be augmented by precipitation on the fracture walls. Where the system is open, the initial drop in aperture may continue, and accelerate, where the influent fluid is oversaturated with respect to the equilibrium mineral concentration within the fluid, or may reverse, if undersaturated. This simple zero‐dimensional model is capable of representing the intricate behavior observed in experiments where the feasibility of fracture sealing concurrent with net dissolution is observed. This zero‐order model is developed as a constitutive model capable of representing key aspects of changes in the transport parameters of the continuum response of fractured media to changes in stress, temperature and chemistry. Copyright © 2009 John Wiley & Sons, Ltd.
Exponential basis functions in solution of static and time harmonic elastic problems in a meshless style
Authors: Boroomand B. , Soghrati S. , Movahedian B. 
Published: September 2009

AbstractIn this paper, exponential basis functions (EBFs) are used in a boundary collocation style to solve engineering problems whose governing partial differential equations (PDEs) are of constant coefficient type. Complex‐valued exponents are considered for the EBFs. Two‐dimensional elasto‐static and time harmonic elasto‐dynamic problems are chosen in this paper. The solution procedure begins with first finding a set of appropriate EBFs and then considering the solution as a summation of such EBFs with unknown coefficients. The unknown coefficients are determined by the satisfaction of the boundary conditions through a collocation method with the aid of a consistent and complex discrete transformation technique. The basis and various forms of the transformation have been addressed and discussed. We shall propose several strategies for selection of EBFs with the aid of the basis explained for the transformation. While using the transformation, the number of EBFs should not necessarily be equal to (or less than) the number of boundary information data. A library of EBFs has also been presented for further use. The effect of body forces is included in the solution via construction of particular solution by the use of the discrete transformation and another series of EBFs. A number of sample problems are solved to demonstrate the capabilities of the method. It has been shown that the time harmonic problems with high wave number can be solved without much effort. The method, categorized in meshless methods, can be applied to many other problems in engineering mechanics and general physics since EBFs can easily be found for almost all problems with constant coefficient PDEs. Copyright © 2009 John Wiley & Sons, Ltd.
Energy–momentum consistent finite element discretization of dynamic finite viscoelasticity
Authors: Groß M. , Betsch P. 
Published: September 2009

AbstractThis paper is concerned with energy–momentum consistent time discretizations of dynamic finite viscoelasticity. Energy consistency means that the total energy is conserved or dissipated by the fully discretized system in agreement with the laws of thermodynamics. The discretization is energy–momentum consistent if also momentum maps are conserved when group motions are superimposed to deformations. The performed approximation is based on a three‐field formulation, in which the deformation field, the velocity field and a strain‐like viscous internal variable field are treated as independent quantities. The new non‐linear viscous evolution equation satisfies a non‐negative viscous dissipation not only in the continuous case, but also in the fully discretized system. The initial boundary value problem is discretized by using finite elements in space and time. Thereby, the temporal approximation is performed prior to the spatial approximation in order to preserve the stress objectivity for finite rotation increments (incremental objectivity). Although the present approach makes possible to design schemes of arbitrary order, the focus is on finite elements relying on linear Lagrange polynomials for the sake of clearness. The discrete energy–momentum consistency is based on the collocation property and an enhanced second Piola–Kirchhoff stress tensor. The obtained coupled non‐linear algebraic equations are consistently linearized. The corresponding iterative solution procedure is associated with newly proposed convergence criteria, which take the discrete energy consistency into account. The iterative solution procedure is therefore not complicated by different scalings in the independent variables, since the motion of the element is taken into account for solving the viscous evolution equation. Representative numerical simulations with various boundary conditions show the superior stability of the new time‐integration algorithm in comparison with the ordinary midpoint rule. Both the quasi‐rigid deformations during a free flight, and large deformations arising in a dynamic tensile test are considered. Copyright © 2009 John Wiley & Sons, Ltd.
Scalar wave equation by the boundary element method: A D‐BEM approach with constant time‐weighting functions
Authors: Carrer J. A. M. , Mansur W. J. 
Published: September 2009

AbstractA D‐BEM approach, based on time‐weighting residuals, is developed for the solution of two‐dimensional scalar wave propagation problems. The modified basic equation of the D‐BEM formulation is generated by weighting, with respect to time, the basic D‐BEM equation, under the assumption of linear and cubic time variation for the potential and for the flux. A constant time‐weighting function is adopted. The time integration reduces the order of the time‐derivative that appears in the domain integral; as a consequence, the initial conditions are directly taken into account. An assessment of the potentialities of the proposed formulation is provided by the examples included at the end of the work. Copyright © 2009 John Wiley & Sons, Ltd.