bluuebunny/crossref_metadata_2025_split huggingface dataset:
Secular trend of adhesive capsulitis
Authors: White D. , Choi H. , Peloquin C. , Zhu Y. , Zhang Y. 
Published: September 2011

AbstractObjectiveAdhesive capsulitis (AC) is a painful shoulder disorder resulting in restrictions of daily activities. Given the recent increase in risk factors for AC, such as diabetes mellitus, research is needed to examine if the incidence of AC has also increased. Therefore, the purpose of this study was to describe the secular trend of AC.MethodsSubjects were from The Health Improvement Network, an electronic medical record database of general practices across the UK from 1995–2008. General practitioners diagnosed AC. We included subjects ages 40–79 years and defined an incident case as the first diagnosis of AC following at least 1 year of enrollment in the database. We examined the potential independent effects of age, calendar time, and birth cohort using an age–period–cohort model. To approximate effect estimates, we applied proportional hazards models and separately adjusted for diabetes mellitus.ResultsOf 2,188,958 subjects (50.0% women), the incidence of AC was 2.36 and 3.38 per 1,000 person‐years for men and women, respectively. Age–period–cohort model graphs suggested a secular trend due to a birth cohort, but not calendar effect. For each 10‐year increment in birth cohort, the incidence rate increased by 8% in women (hazard ratio 1.08, 95% confidence interval 1.05–1.13). There was no increase in AC incidence for men. Adjusting for diabetes mellitus did not change these associations materially.ConclusionWe found women born more recently are at a higher risk of developing AC compared with women born earlier. Future research is needed to identify risk factors that may be responsible for this increase.
Effectiveness of dexamethasone iontophoresis for temporomandibular joint involvement in juvenile idiopathic arthritis
Authors: Mina Rina , Melson Paula , Powell Stephanie , Rao Marepalli , Hinze Claas , Passo Murray , Graham T. Brent , Brunner Hermine I. 
Published: September 2011

AbstractObjectiveTemporomandibular joint (TMJ) involvement is common in juvenile idiopathic arthritis (JIA). Dexamethasone iontophoresis (DIP) uses low‐grade electric currents for transdermal dexamethasone delivery into deeper anatomic structures. The purpose of this study was to assess the safety and effectiveness of DIP for the treatment of TMJ involvement in JIA, and to delineate variables that are associated with improvement after DIP.MethodsMedical records of all JIA patients who underwent DIP for TMJ involvement at a larger tertiary pediatric rheumatology center from 1997–2011 were reviewed. DIP was performed using a standard protocol. The effectiveness of DIP was assessed by comparing the maximal interincisor opening (MIOTMJ) and the maximal lateral excursion (MLETMJ) before and after treatment.ResultsTwenty‐eight patients (ages 2–21 years) who received an average of 8 DIP treatment sessions per involved TMJ were included in the analysis. Statistically significant improvement in the median MIOTMJ (P < 0.0001) was observed in 68%. The median MLETMJ (P = 0.03) improved in 69%, and resolution of TMJ pain occurred in 73% of the patients who had TMJ pain at baseline. Side effects of DIP were transient site erythema (86%), skin blister (4%), and metallic taste (4%). Improvement in TMJ range of motion from DIP is associated with lower MIOTMJ, lower MLETMJ, and absence of TMJ crepitus at baseline.ConclusionIn this pilot study, DIP appeared to be an effective and safe initial treatment of TMJ involvement in JIA, especially among patients with decreased TMJ measurements. Prospective controlled studies are needed.
Microstructure and Properties of Spark Plasma Sintered Carbon Nanotube Reinforced Aluminum Matrix Composites
Authors: Yadav Vineet , Harimkar Sandip P. 
Published: September 2011

AbstractIn this paper, spark plasma sintering (SPS) of multi‐walled carbon nanotube (CNT) reinforced aluminum matrix composites is reported. Ball milling of the Al‐CNT mixture with polyacrylic acid (PAA) dispersion agent followed by SPS resulted in uniform dispersion of CNTs in dense composite compacts. Significant improvement in microhardness, nanohardness, and compressive yield strength was observed with 2 wt% CNT reinforcement in aluminum matrix composites. The Al‐CNT composites further exhibited improved wear resistance and lower friction coefficient due to strengthening and self‐lubricating effects of CNTs.
Ti–6Al–4V–0.5B—A Modified Alloy for Implants Produced by Metal Injection Molding
Authors: Ebel Thomas , Blawert Carsten , Willumeit Regine , Luthringer Bérengère J. C. , Ferri Orley Milagres , Feyerabend Frank 
Published: September 2011

AbstractPermanent implants have to fulfill a great variety of requirements related to both material and geometry. In addition, manufacturing costs play a role, which is getting steadily more and more important. Metal Injection Molding (MIM) of titanium alloy powders may contribute to the development of implants with higher functionality without increasing the price. High degree of freedom with regard to geometry, high material efficiency, and the possibility to create even porous structures are main benefits from applying this technique. Today, even long‐term implants made from Ti–6Al–4V by MIM are commercially available. However, in order to improve fatigue behavior it is beneficial to perform a minor variation of Ti–6Al–4V by adding a low amount of boron. In this paper the mechanical, biological, and corrosion properties of specimens manufactured from Ti–6Al–4V–0.5B alloy by MIM are presented. In order to exclude unknown reactions in the body environment due to the boron content, corrosion, and biological tests are performed. Tensile and fatigue tests characterize the mechanical properties. Potentiodynamic polarization and electrochemical impedance spectroscopy are done in comparison to wrought and to MIM processed Ti–6Al–4V material. For cell experiments cancellous bone cells are cultured to perform adhesion, proliferation, and viability experiments. The results presented here show that the alloy Ti–6Al–4V–0.5B satisfies all basic needs of a material for highly loaded permanent implants manufactured by MIM.
Simultaneous Electrical and Thermoelectric Parameter Retrieval via Two Terminal Current–Voltage Measurements on Individual ZnO Nanowires
Authors: Liu Yang , Zhang Zhiyong , Wei Xianlong , Li Quan , Peng Lian‐Mao 
Published: September 2011

AbstractThe thermoelectric parameters, in particular the thermal conductivity and dimensionless figure of merit ZT, of ZnO nanowires, are estimated via two terminal current–voltage measurements. The measurements are carried out in situ in a transmission electron microscope and negative differential conductance is observed on individually suspended ZnO nanowires. From the low bias region of the current–voltage curve, the electrical parameters, including carrier concentration and mobility, are obtained by fitting the experimental data using a metal–semiconductor–metal model. The thermal conductivity is extracted from the high bias region of the same current–voltage curve using a self‐consistent method, which combines the self‐heating thermal conduction and electrical transport properties of ZnO nanowires. It is shown that the thermal conductivity of ZnO nanowires is suppressed significantly in comparison with that of bulk ZnO, which is attributed to the strong surface scattering of phonons. The thermal conductivity is also found to decrease more steeply than the expected $ {1 \mathord{\left/{\vphantom {1 T}} \right.} T} $ trend, but does obey a $ {1 \mathord{\left/{\vphantom {1 {\left({\alpha T + \beta T^2} \right)}}} \right. } {\left({\alpha T + \beta T^2} \right)}} $ relation; this is shown to result from four‐phonon processes at high temperatures. The dimensionless figure of merit ZT is determined to be about 0.1 at 970 K. Finally, the thermoelectric properties of individual ZnO nanowires are also discussed, indicating that ZnO nanowires are promising high temperature thermoelectric materials.
Electronic Granularity and the Work Function of Transparent Conducting ZnO:Al Thin Films
Authors: Jaramillo Rafael , Ramanathan Shriram 
Published: September 2011

AbstractControlling the efficiency of electron transport across oxide interfaces is essential for numerous emerging technologies including advanced photovoltaics and light emitting devices. This work illuminates the connections between granular structure, defect chemistry, and the work function of a technologically important transparent conductor, ZnO:Al. Visual evidence is provided for a model of grain boundary oxidation in the form of nanometer‐scale heterogeneity in the contact potential between grains and grain boundaries, a phenomenon referred to as electronic granularity. By correlating scanning probe data with photoemission spectroscopy we relate electronic granularity to defect chemistry and, importantly, account for the overall trends in work function. The resulting physical picture connects heterogeneity at the nanoscale to macroscopic properties, informs the design of transparent electrodes, and may be broadly relevant to granular oxide conductors.
Efficient Synthesis of Pt Nanoparticles Supported on Hydrophobic Graphitized Carbon Nanofibers for Electrocatalysts Using Noncovalent Functionalization
Authors: Oh Hyung‐Suk , Kim Hansung 
Published: September 2011

AbstractAs an alternative to the oxidative acid treatment, a noncovalent π–π interaction method is employed to deposit Pt electrocatalysts on highly hydrophobic carbon nanofibers (CNFs) for the application of polymer electrolyte membrane (PEM) fuel cells. Three different functionalization agents, namely benzyl mercaptan (BM), 1‐aminopyrene (AP), and 1‐pyrenecarboxylic acid (PCA), are used to functionalize CNFs and the effect of these groups on the electrochemical properties is examined. While the BM and AP act as a poison to Pt catalyst, the functionalization of CNF with PCA improves the distribution and loading of Pt as well as reducing the sintering of Pt particles. From the carbon corrosion test, unlike the oxidative acid treatment, the PCA treatment sustains the corrosion resistance of CNFs because it preserves the intrinsic properties of CNFs without damaging their surface structure. Therefore, the PCA treatment is a very effective way to prepare catalysts for PEM fuel cells and also extended to the fabrication of graphitized‐carbon‐supported catalysts of other precious metal for various applications.
Enamine‐Mediated Addition of Aldehydes to Cyclic Enones
Authors: Schietroma Daniele M. Scarpino , Monaco Mattia R. , Visca Valerio , Insogna Susanna , Overgaard Jacob , Bella Marco 
Published: September 2011

AbstractThe O‐trimethylsilylated α,α‐diphenylprolinol‐catalyzed addition of aldehydes to cyclic unsaturated enones is described. The apparently unusual stereochemical outcome is discussed.
Phosphine‐Free Palladium Catalytic System for the Selective Direct Arylation of Furans or Thiophenes bearing Alkenes and Inhibition of Heck‐Type Reaction
Authors: Chen Lu , Roger Julien , Bruneau Christian , Dixneuf Pierre H. , Doucet Henri 
Published: September 2011

AbstractPalladium acetate associated to potassium carbonate as catalytic system has been found to efficiently catalyse the direct 5‐arylation of furans or thiophenes bearing enal, enone or acrylate functions at carbon C‐2, and to inhibit the Heck‐type reaction. The nature of the base is crucial to control the selectivity of the arylation. In the presence of electron‐deficient aryl bromides and potassium carbonate as the base, the direct arylation is favoured, whereas the use of potassium fluoride gave selectively the Heck‐type product, and tri‐n‐butylamine the reductive addition product.
Hydroxynitrile Lyase from Arabidopsis thaliana: Identification of Reaction Parameters for Enantiopure Cyanohydrin Synthesis by Pure and Immobilized Catalyst
Authors: Okrob Daniel , Paravidino Monica , Orru Romano V. A. , Wiechert Wolfgang , Hanefeld Ulf , Pohl Martina 
Published: September 2011

AbstractThe (R)‐selective hydroxynitrile lyase from Arabidopsis thaliana (AtHNL) is a promising biocatalyst for the synthesis of a broad range of chiral cyanohydrins. However, the enantiomeric excess of the reaction is strongly compromised by a non‐catalyzed side reaction resulting in racemic cyanohydrins besides the chiral product obtained by enzymatic catalysis. This reaction is influenced by the pH value, the temperature and the water content of the reaction medium. In aqueous media this side reaction can be suppressed at low pH (4–5) and by lowering the temperature. However both approaches are not possible with AtHNL, since the enzyme is rapidly inactivated below pH 5.4, which prevents its use in aqueous media or two‐phasic aqueous‐organic reaction systems. Alternatively the side reaction can be suppressed by lowering the water concentration in the reaction system as far as possible. This approach was successfully tested for AtHNL using buffer‐saturated methyl tert‐butyl ether (MTBE) as a reaction medium for the hydrocyanation of aromatic, heteroaromatic and aliphatic aldehydes. Here we compare the activity and stability of AtHNL immobilized on celite (celite‐AtHNL) and in solgel (solgel‐AtHNL) relative to the precipitated enzyme, which was directly used in the organic solvent. Surprisingly, AtHNL was activated (up to 10‐fold) upon solgel immobilization, an effect that was up to now only described for solgel‐immobilized lipases. In contrast to lipases, AtHNL is not stabilized by the solgel. Best results were obtained with AtHNL adsorbed on celite, which is an easy and efficient way of immobilization and shows good recyclability (>5 cycles), storability (τ1/2=71 days, 4 °C) and excellent catalytic properties upon adjustment of a relative water content of 26% water per g celite‐AtHNL as determined by thermogravimetry.
Synthesis of Enantiomerically Enriched Dimers of Vinylphenols by Tandem Action of Laccases and Lipases
Authors: Gavezzotti Paolo , Navarra Cristina , Caufin Stefania , Danieli Bruno , Magrone Pietro , Monti Daniela , Riva Sergio 
Published: September 2011

AbstractThe tandem use of laccases and lipases has been exploited for the simple preparative synthesis of enantiomerically enriched dimeric phenols. Laccase‐catalyzed oxidation of isoeugenol (1) and vinylguaiacol (7) in biphasic systems gave as main products the racemic compounds 6 and 8, possessing structures similar to the β‐5 dimers found in lignin. The synthesis of enantiomerically enriched 6 and 8 could be achieved by alcoholysis reactions catalyzed by commercial preparations of lipases in organic solvents. Although the E values were quite low (due to the “remote” stereocenters to be discriminated), the enantio‐complementary behavior of the tested lipases allowed the simple isolation of the target compounds with ee up to 90%. It is noteworthy that these results have been achieved in vitro exploiting commercially available enzymes, without using the so‐called “dirigent” proteins evolved by nature to direct the enantioselective coupling of phenols in vivo.
An Efficient Dynamic Kinetic Resolution of N‐Heterocyclic 1,2‐Amino Alcohols
Authors: Lihammar Richard , Millet Renaud , Bäckvall Jan‐E. 
Published: September 2011

AbstractA chemoenzymatic dynamic kinetic resolution (DKR) of N‐heterocyclic amino alcohols is described. Various lipases were studied as biocatalysts for the kinetic resolution of N‐heterocyclic 1,2‐amino alcohols. The influence of the support of the enzymes on the enantioselectivity in the resolution of different substrates is highlighted. Various 3‐acetoxypyrrolidines and ‐piperidines were obtained in high yield and high enantiomeric excess in efficient DKR reactions.
Microwave material processing—a review
Authors: Chandrasekaran S. , Ramanathan Srinivasan , Basak Tanmay 
Published: September 2011

AbstractMicrowave heating is caused by the ability of the materials to absorb microwave energy and convert it to heat. This article represents a review on fundamentals of microwave heating and their interaction with materials for various applications in a comprehensive manner. Experimental studies of single, multimode, and variable frequency microwave processing were reviewed along with their applications. Modeling of microwave heating based on Lambert's law and Maxwell's electromagnetic field equations have also been reviewed along with their applications. Modeling approaches were used to predict the effect of resonances on microwave power absorption, the role of supports for microwave heating, and to determine the nonuniformity on heating rates. Various industrial applications on thermal processing have been reviewed. There is tremendous scope for theoretical and experimental studies on the athermal effects of microwaves. Some of the unresolved problems are identified and directions for further research are also suggested. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Two‐dimensional model of methane thermal decomposition reactors with radiative heat transfer and carbon particle growth
Authors: Caliot Cyril , Flamant Gilles , Patrianakos Giorgos , Kostoglou Margaritis , Konstandopoulos Athanasios G. 
Published: September 2011

AbstractA two‐dimensional model of methane thermal decomposition reactors is developed which accounts for coupled radiative heat and polydisperse carbon particle nucleation, growth, and transport. The model uses the Navier–Stokes equations for the fluid dynamics, the radiative transfer equation for methane and particle species radiation absorption, the advection–diffusion equation for gas and particle species transport, and a sectional method for particle species nucleation, heterogenous growth, and coagulation. The model is applied to a tubular laminar flow reactor. The simulation results indicate the development of a reaction boundary layer inside the reactor, which results in significant variation of the local particle size distribution across the reactor. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2545–2556, 2012
Surface modification of polythiophene and poly(3‐methyl thiophene) films by graft copolymerization
Authors: Liu Fangjun , Chen Yubo , Wei Yuyan , Li Liang , Shang Songmin 
Published: September 2011

AbstractPolythiophene (PTH) and poly(3‐methyl thiophene) (PMT) films were electrochemically polymerized in an electrolyte solution of boron fluoride–ethyl ether. Ozone‐pretreated PTH and PMT films were subjected to UV‐light‐induced graft copolymerization with different monomers, including poly(ethylene glycol) monomethacrylate, acrylic acid, and glycidyl methacrylate. Surface grafting with the hydrophilic polymers gave rise to more hydrophilic PTH and PMT films. The structure and chemical composition of each copolymer surface were studied by X‐ray photoelectron spectroscopy. The surface grafting with the hydrophilic polymers resulted in a more hydrophilic PTH film. The dependence of the density of surface grafting and the conductivities of the grafted PTH and PMT films on the ozone pretreatment was also studied. A large amount of the grafted groups at the surface of the PTH and PMT films remained free for further surface modification and functionalization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Diazotization of anilines and diazo coupling with a coupling component mediated by a polymer‐supported sodium nitrite and a polymeric acid
Authors: Karimi Zarchi Mohammad Ali , Karimi Mohammad 
Published: September 2011

AbstractPolymer‐supported reagents have become the subject of considerable and increasing interest as insoluble materials in the organic synthesis. In this study, diazonium salts are generated and are coupled with a coupling component by using a polymer supported nitrite and a polymeric acid. In this procedure, the azo chromophores are formed in a clean and efficient manner, the work–up is easy and yields are high to excellent. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Phase transformation mechanisms and piezoelectric properties of poly(vinylidene fluoride)/montmorillonite composite
Authors: Zhang Y. Y. , Jiang S. L. , Yu Y. , Xiong G. , Zhang Q. F. , Guang G. Z. 
Published: September 2011

AbstractPoly(vinylidene fluoride) (PVDF)/montmorillonite (MMT) composite with different MMT contents were prepared by solutions‐casting method. The effects of MMT on crystalline structure, morphology, dielectric property, piezoelectric property and phase transformation mechanism were studied. The results showed that acted as effective nucleation agents, the orientation of MMT were almost parallel to the surface of the film. The beta phase in the PVDF matrix was increased and the alpha phase was decreased. Relative dielectric constant and loss of the composite were increased with the increasing of MMT. The d33 was also increased with MMT, which reached a maximum (5.8pC/N) with 2.0 wt % MMT. The mechanisms of changes in phase transformation and piezoelectric property were proposed based on experiment results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Surface modification of ultra‐flat polydimethylsiloxane by UV‐grafted poly(acrylic acid) brushes
Authors: Yang HaiJun , Hou ZhengChi , Hu Jun 
Published: September 2011

AbstractThe graft density and surface topography of ultra‐flat polydimethylsiloxan films grafted with poly(acrylic acid) brushes by UV irradiation are investigated. The graft density keeps increase with the irradiation time and with the monomer concentration to a maximum, after which it remains unchanged in the former case or drops in the latter. Atomic force microscopy results show that a longer irradiation time, a higher monomer concentration and the addition of ethanol in the grafting solution are favorable to obtain the grafted polydimethylsiloxan films with flat surface. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, characterization of the luminescent lanthanide complexes with copolymer of (Z)‐4‐oxo‐4‐phenyloxyl‐2‐butenoic acid and styrene
Authors: Li Tong , Su Yi‐Bing , Huang Yong , Yang Ying 
Published: September 2011

AbstractThe copolymers of (Z)‐4‐oxo‐4‐phenoxyl‐2‐butenoic acid with styrene (PSt/OPBA) and their macromolecular luminous lanthanide complexes (Ln‐PSt/OPBA) have been synthesized and characterized by means of GPC, elemental analysis, FTIR, X‐ray powder diffraction, spectral analysis, and thermal analysis. The IR studies showed that the carboxylic groups on the side chain of the polymer were coordinated to lanthanide ions by bidentate manner. However, the ethereal oxygen, instead of carbonyl, also bonded to the central lanthanide ions, which was an intriguing phenomenon for ester‐coordinated complexes. X‐ray diffraction experiments revealed that these PSt/OPBA copolymers were amorphous, but Ln‐PSt/OPBA were crystalline, in which the complex Eu‐Lc belonged to a high symmetric structure of orthorhombic quadratic system, with a = 10.59 ± 0.02 Å, c = 8.02 ± 0.01 Å; c/a = 0.763. In addition, the value δ (the number of free carboxylic groups) in Ln‐PSt/OPBA complexes increased with the decreasing mole ratio of styrene in the copolymers, while it decreased with increasing pH values of the solution. Eu3+ and Tb3+ complexes exhibited characteristic fluorescence with comparatively high brightness and good monochromaticity, and the fluorescence intensity was enhanced with increasing the content of lanthanide up to around 18 wt % without typical fluorescence concentration quenching behavior in the solid state. So using polymers as a matrix, Ln‐PSt/OPBA are likely to provide new materials that possess specific properties and desired features. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012