bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elongated Titanate Nanostructures and Their Applications
Authors: Bavykin Dmitry V. , Walsh Frank C. 
Published: February 2009

AbstractRecent advances in the synthesis, characterisation and applications of elongated titanate and TiO2nanostructures (including nanotubes, nanofibres and nanorods) are reviewed. The physicochemical properties of nanostructures, such as high surface area, efficient ion‐exchange properties, electron and proton conductivity and high aspect ratio, are described in connection with a particular application. Practical aspects of the preparation, stability and transformation of elongated titanates are considered. A critical survey of the literature is provided together with the development of prospectiveenergy applications of elongated titanates in catalysis, photocatalysis, electrocatalysis, solar cells, fuel cells, lithium batteries and hydrogen storage. Other applications utilising the high aspect ratio of elongated nanostructures include biomedical implants, sensors, drug delivery systems and smart, tribological composite coatings. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Cobalt and Silver Complexes of Terdentate Pyrazine‐Based Amide Ligands and Assembly of Monocobalt Building Blocks through a Silver Connector
Authors: Hellyer Ryan M. , Larsen David S. , Brooker Sally 
Published: February 2009

AbstractTwo terdentate pyrazine‐based amide ligands have been prepared from methyl pyrazine‐2‐carboxylate and 2‐(aminomethyl)pyridine (HL1M) or 2‐(2‐aminoethyl)pyridine (HL1E) in order to probe the potential of the “spare” nitrogen atom “out the back” of the pyrazine ring to coordinate to a different metal ion and thereby act as a linker between complexes. Two inert cobalt(III) complexes, [CoIII(L1M)2](BF4)·${1 \over 4}$H2O and [CoIII(L1E)2](BF4)·${1 \over 2}$H2O, have been prepared as building blocks and the silver(I) coordination of the ligands also probed, forming {[AgI(HL1M)]BF4}∞ and [AgI2(HL1LE)2](BF4)2. The [CoIII(L1E)2](BF4) building block has been successfully connected to a second such complex by coordination of silver(I) to a “spare” pyrazine nitrogen atom on each complex, resulting in [{CoIII(L1E)2}2AgI](BF4)(NO3)2. All five complexes have been structurally characterised. Mass spectra and cyclic voltammetry studies on “aged” (kept in solution in air for 2 d) samples clearly showed that the cobalt complex of the methylene‐linked ligand was prone to slow ligand oxidation, forming [CoIII(L1Mox)(L1M)](BF4) and [CoIII(L1Mox)2](BF4). Fresh samples of [CoIII(L1M)2](BF4)·${1 \over 4}$H2O and [CoIII(L1E)2](BF4)·${1 \over 2}$H2O undergo a chemically reversible one‐electron reduction in dry acetonitrile, at –0.71 and –0.48 V vs. 0.01 M AgNO3/Ag, respectively, consistent with the methylene‐linked ligand being better able to stabilise the higher oxidation state of cobalt than the ethylene‐linked ligand.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
On the sum capacity of aT‐userN‐frequency multiple access channel with noise
Authors: Sharma Manish , Portugheis Jaime 
Published: February 2009

AbstractIn this paper, we investigate the sum capacity of a noisy multiple access channel (MAC): theT‐userN‐frequency noiseless MAC in cascade with a noisy channel. The noisy channel includes frequency‐selective Rayleigh fading and Additive White Gaussian Noise (AWGN). The receiver may use multiuser detection (MUD) or single user detection (SUD). We show that when using SUD, the uniform distribution achieves sum capacity. Considering MUD and assuming that all users have the same input distribution, we show through numerical optimisation, that, for most relevant values ofTandN, a product of uniform input distributions maximises a tight upper bound on sum capacity. Numerical results were obtained and it was observed that, for fixedN, there is a value ofTwhich maximises sum capacity. As expected, the results also show that there is a significant gain in sum capacity when MUD is used. Copyright © 2009 John Wiley & Sons, Ltd.
Pricing in vitro fertilization procedures
Authors: Dukes Anthony J. , Tyagi Rajeev K. 
Published: February 2009

AbstractThis paper examines the economics of pricing practices at artificial reproductive clinics, which have introduced money‐back guarantees (MBGs) for in vitro fertilization. We identify incentives for clinics to offer MBGs and evaluate the impact on couples' choices and on social welfare. Introducing MBGs allows a clinic to (i) segment couples simultaneously on their relative fertility and on risk preferences; (ii) offer quantity discounts to relatively infertile couples; and (iii) offer some risk‐sharing to couples for this costly procedure, whose outcome is uncertain. Our results also show how the addition of MBGs can affect the overall social welfare. Copyright © 2009 John Wiley & Sons, Ltd.
Investment in quality improvement: how to maximize the return
Authors: Gandjour Afschin 
Published: February 2009

AbstractToday, one of the most pressing concerns of health‐care policymakers in industrialized countries are deficits in the quality of health care. This paper presents a decision program that addresses the question in which disease areas and at what intensity to invest in quality improvement (QI) in order to maximize population health. The decision program considers both a budget constraint as well as time constraints of educators and health professionals to participate in educational activities. The calculations of the model are based on a single assumption which is that more intense quality efforts lead to larger QIs, but with diminishing returns. This assumption has been validated by previous studies. All other relationships described by the model are deduced from this assumption. The model uses data from QI trials published in the literature. Thus, it is able to assess how the vast number of published QI strategies compare in terms of their value. Copyright © 2009 John Wiley & Sons, Ltd.
Biocompatibility and osseointegration of reconstituted keratin in an ovine model
Authors: Dias George J. , Peplow Philip V. , McLaughlin Andrew , Teixeira Fernanda , Kelly Robert J. 
Published: February 2009

AbstractReconstituted keratin has potential as a raw material for orthopaedic applications. The aim of this study was to investigate the in vivo biocompatibility and osseointegration of keratin materials in an ovine model. Six different modifications of the keratin polymer, based on porous or dense constructs, regenerated by either neutral or acidic treatment, with or without hydroxyapatite, were made as small rods and inserted into drilled round defects in the femur and tibia of sheep. Histology was carried out on samples taken at different time points up to 24 weeks postsurgery. All keratin implants showed similar histological profiles, which included granulation tissue surrounding and infiltrating the implants, followed by new bone formation radiating from the existing bone. By 8 weeks, new bone had grown to within a short distance of the implant surface, and in some places was in direct apposition to the keratin implant. In the 12 to 24‐week period, there was peripheral resorption and infiltration of bony trabeculae with regard to the porous constructs only. The tissue reaction appeared to model that of a fairly inert material. Further work on improving the extent of osseointegration and acceleration of the biodegradation rate of reconstituted keratin is underway. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Efficacy of polarized hydroxyapatite and silk fibroin composite dressing gel on epidermal recovery from full‐thickness skin wounds
Authors: Okabayashi Rumi , Nakamura Miho , Okabayashi Tamaki , Tanaka Yumi , Nagai Akiko , Yamashita Kimihiro 
Published: February 2009

AbstractHydroxyapatite (HA) has been widely used to produce biomaterials. We reported that electrically polarized HA (pHA) induces cells as a scaffold. Recently, in the biomedical field, many studies are underway, seeking new applications of silk fibroin (SF), because SF can be gelatinized and still retain its biocompatibility and permeability. To develop an innovative composite material for effective wound dressings, we added pHA powder to SF and gelatinized the compound. We then applied the gel composite on full‐thickness porcine skin wounds for investigation of its healing effect. The pHA transforms the SF structure into a porous three‐dimensional scaffold. It was found that the SF gel containing pHA (pHA/SF) had higher promotive effects on wound healing, re‐epithelization, and matrix formation than did the other prepared gel composites in the study. The pHA/SF effectively advanced the maturation of fibroblast cells benefiting from its structural advantages and stored charges. To our knowledge, this is the first report of the preparation of pHA/SF gel and identification of its wound‐healing effects in vivo. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Bioactivity, pre‐osteoblastic cell responses, and osteoconductivity evaluations of the electrospun non‐woven SiO2–CaO gel fabrics
Authors: Seol Yang‐Jo , Kim Kyoung‐Hwa , Kang Young Mi , Kim In Ae , Rhee Sang‐Hoon 
Published: February 2009

AbstractThe evaluations of the fibers characteristics, bioactivity, pre‐osteoblastic cell responses, and osteoconductivity of the non‐woven SiO2–CaO gel fabric made by electrospinning method was carried out. Silica gels with four different calcium contents were prepared by condensation following hydrolysis of tetraethyl orthosilicate under acidic conditions. The molar ratios of Ca to Si prepared ranged from 0 to 0.15. SiO2–CaO gel fabrics were heat‐treated at 300°C for 3 h after spinning under an electric field of 2 kV/cm. As the Ca to Si ratio increased, the diameter of electrospun SiO2–CaO gel fibers increased because the viscosity of the SiO2–CaO gel solution increased. The apatite‐forming ability of heat‐treated, non‐woven SiO2–CaO gel fabric was evaluated in simulated body fluid and tended to increase with an increasing Ca to Si molar ratio. However, proliferation and differentiation tended to decrease with an increasing Ca to Si molar ratio. The sample which had the Ca to Si ratio as 0.10 showed good osteoconductivity in vivo in the calvarial defect New Zealand white rabbit model compared to that had the Ca to Si ratio as 0 and empty defect. These results strongly suggest that non‐woven SiO2–CaO gel fabric made by the electrospinning method has potential for application as a bone grafting material. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Antibacterial properties of a tri‐sodium citrate modified glass polyalkenoate cement
Authors: Wren A. W. , Boyd D. , Thornton R. , Cooney J. C. , Towler M. R. 
Published: February 2009

AbstractPrimary deep infection following joint replacement surgery accounts for 7% of all revisions. Glass polyalkenoate cements (GPCs) have previously been shown to exhibit antibacterial properties. The present study had two objectives. The first was to determine if addition of tri‐sodium citrate (TSC) to the powder phase of an Al‐free GPC (0.04 SrO–0.12 CaO–0.36 ZnO–0.48 SiO2, by mole fraction) enhanced the resultant cement's antibacterial properties against three strains of bacteria that are commonly found in periprosthetic sites following total joint replacements (TJRs); namely, E. coli, B. fragilis, and S. epidermidis. Four cement sets were prepared, which contained 0 wt% TSC (control), 5 wt% TSC, 10 wt% TSC, and 15 wt% TSC. All the TSC‐modified cements were found to exhibit large inhibition zones against all the bacterial strains, especially the cement containing 15 wt% TSC against E. coli. The antibacterial properties of the TSC containing GPCs are attributed to the release of Zn and Na ions from the cements and the presence of the TSC. The second objective was to investigate if, when a modified GPC is embedded in a bovine bone model, ionic transfer occurs. It was found that Zn ions migrated from the cement to the surrounding bone, particularly at the cement–bone interface. This is a desirable outcome as Zn ions are known to play a vital role in both bone metabolism and the regeneration of healthy bone. The present results point to the potential clinical benefits of using TSC‐modified GPCs in TJRs. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Effect of cross‐link density on the high pressure crystallization of UHMWPE
Authors: Oral Ebru , Godleski‐Beckos Christine , Ghali Bassem W. , Lozynsky Andrew J. , Muratoglu Orhun K. 
Published: February 2009

AbstractUltrahigh molecular weight polyethylene (UHMWPE) is a bearing surface material for total joint implants. It is radiation cross‐linked for high wear resistance and is melted or treated with vitamin E for oxidative stability. We investigated high pressure crystallization (HPC) of irradiated UHMWPE as an alternative method to improve the mechanical strength while stabilizing the residual free radicals from radiation cross‐linking. HPC of uncross‐linked UHMWPE has resulted in the formation of extended chain crystals and increased crystallinity, leading to improved strength. We hypothesized that increased cross‐link density would hinder crystallization during HPC due to decreased chain mobility. Therefore, we investigated the crystalline structure and tensile mechanical properties of high pressure crystallized 25‐, 65‐ and 100‐kGy irradiated UHMWPE. We also determined free radical content and wear. The strength of 25‐ and 65‐kGy irradiated UHMWPEs was improved by HPC with increased crystallinity and crystal size. 100‐kGy irradiated UHMWPE did not show improved strength, supporting our hypothesis that decreased chain mobility would hinder crystal formation and strength improvement. None of the HPC irradiated UHMWPEs contained detectable free radicals and their wear properties were maintained, suggesting oxidative and mechanical stability in the long term. Therefore, HPC can be used effectively for imparting oxidative stability while strength improvement can be achieved for irradiated UHMWPE with low to moderate cross‐link density. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Flapping of the dissected intima in a case of traumatic carotid artery dissection in a jackhammer worker
Authors: Vadikolias Konstantinos , Heliopoulos John , Serdari Aspasia , Vadikolia Chrissanthi M. , Piperidou Charitomeni 
Published: February 2009

AbstractWe present the sonographic finding of flapping of the dissected intima inside the carotid artery in a 48‐year‐old man who suffered an acute stroke after vigorous use of a jackhammer. The dissected intima was seen to flap inside the lumen regularly and in synchrony with the vessel's pulse. There was no distal segmental stenosis. The extracranial blood flow velocities were within normal limits and transcranial Doppler examination did not reveal any velocity alteration. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound 2009
Solvent‐free chemoselective synthesis of some novel substituted 2‐arylbenzimidazoles using amino acid‐based prolinium nitrate ionic liquid as catalyst
Authors: Rostamizadeh Shahnaz , Aryan Reza , Ghaieni Hamid Reza , Amani Ali Mohammad 
Published: February 2009

Abstract
magnified imageA simple and eco‐friendly protocol for the synthesis of substituted 2‐arylbenzimidazoles is described. In this process, 2‐arylbenzimidazoles were prepared in the presence of a newly introduced ionic liquid prolinium nitrate [Pro]NO3 as catalyst, under solvent‐free condition. This process was performed under mild condition without using any oxidant with good to excellent yields and remarkable chemoselectivity in the absence of any byproduct. The ionic liquid can be recovered easily and reused. J. Heterocyclic Chem., 46, 74 (2009).
Synthetic strategy toward 1,9‐functionalized pyrido[2,3‐d:6,5‐d′]dipyrimidine‐2,4,6,8‐tetrones
Authors: Borzsonyi Gabor , Beingessner Rachel L. , Fenniri Hicham 
Published: February 2009

Abstract
magnified imageA synthetic approach involving a solubilizing protecting group strategy is described to generate pyrido[2,3‐d:6,5‐d′]dipyrimidine‐2,4,6,8‐tetrones functionalized at positions 1 and 9 with alkylamine substitutents. J. Heterocyclic Chem., 46, 79 (2009).
A simple method for the synthesis of 5‐isoxazolyl‐4‐thioxo‐1,3,5‐benzoxadiazocines
Authors: Rajanarendar E. , Rao E. Kalyan , Reddy A. Siva Rami 
Published: February 2009

Abstract
magnified imageSynthesis of novel isoxazolyl 1,3,5‐benzoxadiazocines 5 has been accomplished by condensation of 3‐amino‐5‐methylisoxazole 1 with salicylaldehydes, followed by reduction, treatment with arylisothiocyanates, and subsequent ring closure in the presence of formaldehyde. The methodology used in this synthesis is the first approach of its kind. J. Heterocyclic Chem., 46, 134 (2009).
Calculation of absorption and resonance Raman cross sections of ClO2 in the gas‐phase and in solution: including Duschinsky effects
Authors: Dehestani M. 
Published: February 2009

AbstractThe time‐correlation function formalism has been used to calculate resonance Raman cross sections, excitation profiles, and electronic absorption spectra of the OClO molecule in the gas‐phase and in different solvents like cyclohexane, chloroform, and water. The multidimensional time domain integrals that arise in these calculations have been evaluated for the case in which an X2B1Ã2A1 electronic transition takes place between displaced‐distorted‐rotated harmonic potential energy surfaces. Ab initio calculations have been performed to provide the spectroscopic constants required for the evaluation of these integrals. The calculated absorption spectra and resonance Raman cross sections have been compared with the experimental results. Copyright © 2009 John Wiley & Sons, Ltd.
A Raman approach to pseudo‐cross‐conjugation in mesomeric betaines
Authors: Capel Ferrón C. , Casado J. , López Navarrete J. T. , Dreger A. , Schmidt A. , Ramírez F. J. 
Published: February 2009

AbstractWe demonstrate that Raman spectroscopy is able to discriminate between cross‐conjugated (CC) and pseudo‐cross‐conjugated mesomeric betaines (PCCMBs) by means of key bands sensitive to conjugation. As targets, we have selected the PCCMB 2,5 dimethyl‐1‐phenylpyrazolium‐3‐carboxylate and its isomer the CCMB 1,3‐dimethyl‐2‐phenylpyrazolium‐4 carboxylate. Structurally, they differ only in the position of the carboxylate group bonded to the pyrazolium ring. However, this feature provides different conjugational character. We provide evidences for the fact that this structural difference has a measurable impact in the vibrational wavenumbers as Raman spectroscopy can directly account for it. We also prove that the observed Raman features are not only originated by the kinetic effect caused by the change of the carboxylate position, but this atomic re‐organization also modifies the potential energy of the molecule. This energy directly depends on the electronic structure, which determines the pseudo‐cross‐conjugation character. Copyright © 2009 John Wiley & Sons, Ltd.
Herpes zoster oticus associated with varicella zoster virus encephalitis
Authors: Eskiizmir Görkem , Uz Uzdan , Taşkiran Esra , Ünlü Halis 
Published: February 2009

AbstractRamsay‐Hunt syndrome, herpes zoster oticus (HZO), derived its name from James Ramsay Hunt, who first described it in 1907. It is classically characterized by acute peripheral facial paralysis, herpetic eruptions on the auricle, and vestibulocochlear dysfunction due to the reactivation of varicella zoster virus (VZV). In this Case Report, the authors describe an HZO patient with simultaneous VZV encephalitis. To date, only eight cases of HZO associated with VZV encephalitis have been reported in the English literature. Therefore, the authors discuss all the aspects of this rare entity, including clinical examination, radiological evaluation, laboratory evaluation, and treatment options. Laryngoscope, 2009
Focal adhesion mediated intracellular signaling, Stat3 translocation and osteoblast differentiation: regulation by substratum topography
Authors: Hamilton D. W. , Jamshidi F. , Brunette D. M. 
Published: February 2009

AbstractOsseointegration is a necessary process for stabilization of implants that contact bone. Implant substratum topography has been identified as an important modulator of osteoblast differentiation, although the molecular processes involved are poorly understood. The aim of this study was to assess adhesion mediated molecular events induced in rat calvarial osteoblasts by topographies produced using microfabrication techniques. Specifically, we investigated the activation of tyrosine phosphorylation, focal adhesion kinase (FAK), extracellular regulated kinase 1/2 (ERK‐1/2), janus kinase‐1 and 2 (JAK‐1 and 2), and the transcription factor Stat3. Microfabricated topographies stimulated altered focal adhesion (FA) arrangements, which correlated with regions of increased tyrosine phosphorylation. FAK, and ERK 1/2. Inhibition of JAK‐1 using piceatannol attenuated the phosphorylation of FAK and ERK 1/2 on 30μm deep grooves, but not smooth, but inhibited proliferation on all surfaces tested. Inhibition of microtubule nucleation, JAK‐1, JAK‐2 and phospholipase‐C had no effect on nuclear translocation of Stat3 irrespective of topography. We conclude that nuclear translocation of Stat3 is independent of substratum topography, but JAK‐1 is involved in focal adhesion mediated signal transduction. Further understanding of the molecular regulation of osteoblast differentiation by substratum topography will allow the design of more suitable biomaterials for orthopaedic and dental applications.
Characterization of as‐plasma‐sprayed and incubated hydroxyapatite coatings with high resolution techniques
Authors: Heimann R. B. 
Published: February 2009

AbstractTo improve the reliability of thermally sprayed coatings for human implants application it is vital to understand the changes that morphology, and chemical and phase compositions of the hydroxyapatite coatings undergo when brought in contact with living tissue. In this study, hydroxyapatite (HAp) coatings were deposited onto Ti6Al4V substrates by atmospheric plasma spraying (APS) followed by incubation for up to 84 days in revised simulated body fluid (rSBF) to assess their possible biofunctional performance. Morphology, phase and chemical compositions of as‐sprayed coatings were investigated by synchrotron x‐ray powder diffraction (XRD), laser‐Raman spectroscopy (LRS), and nuclear magnetic resonance spectroscopy (NMR). In addition, incubated coatings were characterized by scanning transmission electron microscopy (STEM) and proton‐induced x‐ray emission (PIXE). The results indicate that during plasma spraying hydroxyapatite transforms to crystalline oxyapatite and ß‐tricalcium phosphate as well as amorphous calcium phosphate (ACP). On incubation crystallization of ACP occurs via fluid flow of solution along cracks and fissures of the coating. The composition develops towards fully crystalline but porous defect apatite containing residual water.
Improved osseointegration of a novel, hydrophilic Ti surface – a review
Authors: Molenberg A. , Schwarz F. , Herten M. , Berner S. , de Wild M. , Wieland M. 
Published: February 2009

AbstractThe high surface energy of sandblasted and acid etched (SLA) titanium surfaces can be retained by keeping them submersed in an isotonic NaCl solution at pH 4 to 6 under a nitrogen atmosphere immediately after the acid‐etching process, thus reducing the adsorption of potential contaminants from the atmosphere. The novel implant surface thus produced shows a strongly increased hydrophilicity, compared to the conventional SLA surface, and is named SLActive.Several animal studies have indicated a faster osseointegration of the SLActive surface, compared to the SLA surface, and improved regeneration in bone defects next to implants. Histological and immunohistochemical studies have shown improved wound healing at the SLActive surface only a few days after implantation and a pilot clinical study has shown the break point from decreasing stability to increasing stability occurring after 2 weeks for SLActive implants, compared to 4 weeks for SLA implants.