bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the impact of magnetic permeability and loss of magnetic composite materials on RFID miniaturization for conformal medical applications
Authors: Martin Lara , Yang Li , Staiculescu Daniela , Li Haiying , Ooi S. L. , Wong C. P. , Tentzeris Manos M. 
Published: November 2008

AbstractThe successful implementation of a flexible magnetic composite material has enabled the investigation of the potential impact on RFID (radio frequency identification) and RF passives miniaturization, considering both material/fabrication properties and geometric design parameters. The benchmarking structure is a short‐circuited quarter‐wavelength rectangular patch antenna for RFID UHF band (400–930 MHz). The antenna is electromagnetically modeled in HFSS full wave EM (electromagnetic) software and optimized using statistical tools, and it is found that the permeability of a practical magnetic composite can enable miniaturization by a factor larger than 3, something that could be replicated for other large‐size RF passives, such as integrated inductors. The impact of the magnetic loss of the composite on the miniaturized antenna performance is also evaluated and the material is reformulated to meet the loss requirements. Then a real RFID tag is implemented for 480 MHz frequency band and good performance of the miniaturized antenna is proven both in planar and conformal configurations. Copyright © 2008 John Wiley & Sons, Ltd.
SHOX gene is expressed in vertebral body growth plates in idiopathic and congenital scoliosis: Implications for the etiology of scoliosis in turner syndrome
Authors: Day Gregory , Szvetko Attila , Griffiths Lyn , McPhee I. Bruce , Tuffley John , LaBrom Robert , Askin Geoffrey , Woodland Peter , McClosky Eamonn , Torode Ian , Tomlinson Francis 
Published: November 2008

AbstractReduced SHOX gene expression has been demonstrated to be associated with all skeletal abnormalities in Turner syndrome, other than scoliosis (and kyphosis). There is evidence to suggest that Turner syndrome scoliosis is clinically and radiologically similar to idiopathic scoliosis, although the phenotypes are dissimilar. This pilot gene expression study used relative quantitative real‐time PCR (qRT‐PCR) of the SHOX (short stature on X) gene to determine whether it is expressed in vertebral body growth plates in idiopathic and congenital scoliosis. After vertebral growth plate dissection, tissue was examined histologically and RNA was extracted and its integrity was assessed using a Bio‐Spec Mini, NanoDrop ND‐1000 spectrophotometer and standard denaturing gel electrophoresis. Following cDNA synthesis, gene‐specific optimization in a Corbett RotorGene 6000 real‐time cycler was followed by qRT‐PCR of vertebral tissue. Histological examination of vertebral samples confirmed that only growth plate was analyzed for gene expression. Cycling and melt curves were resolved in triplicate for all samples. SHOX abundance was demonstrated in congenital and idiopathic scoliosis vertebral body growth plates. SHOX expression was 11‐fold greater in idiopathic compared to congenital (n = 3) scoliosis (p = 0.027). This study confirmed that SHOX was expressed in vertebral body growth plates, which implies that its expression may also be associated with the scoliosis (and kyphosis) of Turner syndrome. SHOX expression is reduced in Turner syndrome (short stature). In this study, increased SHOX expression was demonstrated in idiopathic scoliosis (tall stature) and congenital scoliosis. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 807–813, 2009
Long‐lasting in vivo inotropic effects of the K+ channel blocker 3,4‐diaminopyridine during fatigue‐inducing stimulation
Authors: Van Lunteren Erik , Moyer Michelle , Pollarine Jennifer 
Published: November 2008

AbstractBlocking K+ channels with aminopyridines enhances muscle contractile performance in vitro, but the improvements are relatively short‐lasting during fatigue‐inducing stimulation. We hypothesized that in vivo inotropic actions persist over long periods of fatigue‐inducing stimulation. The effects of 3,4‐diaminopyridine (DAP) were evaluated for rat extensor digitorum longus (EDL) muscle. DAP increased twitch force by 105%. There was a significant leftward shift in the force–frequency relationship, with force values being increased at frequencies up to and including 20 HZ. During repetitive fatigue‐inducing 20‐HZ stimulation, DAP‐induced force increases were large and persisted significantly for at least 30 minutes. Thus, DAP substantially improves contractile performance of EDL muscle in vivo for much longer periods during fatigue‐inducing contractions than in vitro. These data provide support for a potential role for aminopyridines as inotropic agents in applications such as functional electrical stimulation, in which low to medium stimulation frequencies are typically utilized. Muscle Nerve 38: 1616–1622, 2008
Increased expression of acetylcholine receptors in the diaphragm muscle of mdx mice
Authors: Ghedini Paulo C. , Viel Tânia A. , Honda Luciana , Avellar Maria Christina W. , Godinho Rosely O. , Lima‐Landman Maria Teresa R. , Lapa Antônio J. , Souccar Caden 
Published: November 2008

AbstractThe absence of dystrophin in Duchenne muscular dystrophy (DMD) and in the mutant mdx mouse causes muscle degeneration and disruption of the neuromuscular junction. Based on evidence from the denervation‐like properties of these muscles, we assessed the ligand‐binding constants of nicotinic acetylcholine receptors (nAChRs) and the mRNA expression of individual subunits in membrane preparations of diaphragm muscles from adult (4‐month‐old) and aged (20‐month‐old) control and mdx mice. The concentration of nAChRs as determined by the maximal specific [125I]‐α‐bungarotoxin binding (Bmax) in the muscle membranes did not change with aging in both animal strains. When compared to age‐matched control groups, the Bmax in mdx muscles was increased by 65% in adults, and by 103% in aged mice with no alteration of toxin affinity for nAChRs. Reverse‐transcription polymerase chain reaction assays showed that mRNA transcripts for the nAChR α1, γ, α7, and β2, but not the ϵ subunits, were more abundant in mdx than in control muscles. The results indicate increased expression of extrajunctional nAChRs in the mdx diaphragm and reflect impairment of nAChR regulation in dystrophin‐deficient muscles. These observations may be related to the resistance to nondepolarizing muscle relaxants and the high sensitivity to depolarizing agents reported in DMD patients. Muscle Nerve 38: 1585–1594, 2008
Responses of human motoneurons to high‐frequency stimulation of Ia afferents
Authors: Bawa Parveen , Chalmers Gordon 
Published: November 2008

AbstractThis study was designed to extend to humans the findings of classical studies on anesthetized cats, which have examined the discharge of spinal motoneurons in response to high‐frequency stimulus trains delivered to Ia afferents. Experiments were conducted on the monosynaptic pathway in the flexor carpi radialis (FCR) and soleus muscles. Subjects maintained a rhythmic discharge of a single motor unit (SMU) in either the FCR or soleus while homonymous Ia afferents were stimulated with either a single‐ or multipulse train. An n@IPI stimulus train had n pulses (n = 2–4) and an interpulse interval (IPI) of 1–8 ms. For each condition and motor unit, surface electromyographic (EMG) activity was averaged, and peristimulus–time histograms (PSTHs) were constructed for the SMU. The magnitude of the EMG was high for IPI = 1 ms, low for IPI = 2–3 ms, and high for IPI = 4–8 ms. SMU responses showed a similar pattern, which indicated that the increased EMG response was due to the presence of multiple peaks in a PSTH. The key results indicate that: (1) a short, high‐frequency stimulus train enhances the discharge probability of a motoneuron above that observed with a single pulse; and (2) the increased motoneuron responses are significantly greater for the FCR than for the soleus muscle. © 2008 Wiley Periodicals, Inc. Muscle Nerve 38: 1604–1615, 2008
Construction of an efficient evaluative instrument for Myasthenia Gravis: The MG composite
Authors: Burns Ted M. , Conaway Mark R. , Cutter Gary R. , Sanders Donald B. 
Published: November 2008

AbstractWe assessed the performance of items from the Quantitative Myasthenia Gravis (QMG), MMT (Manual Muscle Test), and MG‐ADL (Myasthenia Gravis – Activities of Daily Living) scales, using data from two recently completed treatment trials of generalized MG. Items were selected that were relevant to manifestations of MG, meaningful to both the physician and the patient, and responsive to clinical change. After the 10 items were chosen, they were weighted based on input from MG experts from around the world, considering factors such as quality of life, disease severity, risk, prognosis, validity, and reliability. The MG Composite is easy to administer, takes less than 5 minutes to complete, and requires no equipment. Weighting of the response options of the 10 items should result in ordinal scores that better represent MG status and are more responsive to meaningful clinical change. To better determine its suitability for clinical use and for treatment trials, the MG Composite will be tested prospectively at several academic medical centers and will be used as a secondary measure of efficacy in pending clinical trials of MG. Muscle Nerve 38: 1553–1562, 2008
Characterization of breast cancers and therapy response by MRS and quantitative gene expression profiling in the choline pathway
Authors: Morse David L. , Carroll Danielle , Day Sam , Gray Heather , Sadarangani Pooja , Murthi Shiva , Job Constantin , Baggett Brenda , Raghunand Natarajan , Gillies Robert J. 
Published: November 2008

AbstractTumor choline metabolites have potential for use as diagnostic indicators of breast cancer phenotype and can be non‐invasively monitored in vivo by MRS. Extract studies have determined that the principle diagnostic component of these peaks is phosphocholine (PCho), the biosynthetic precursor to the membrane phospholipid, phosphatidylcholine (PtdCho). The ability to resolve and quantify PCho in vivo would improve the accuracy of this putative diagnostic tool. In addition, determining the biochemical mechanisms underlying these metabolic perturbations will improve the understanding of breast cancer and may suggest potential molecular targets for drug development. Reported herein is the in vivo resolution and quantification of PCho and glycerophosphocholine (GPC) in breast cancer xenografts in SCID mice via image‐guided 31P MRS, localized to a single voxel. Tumor metabolites are also detected using ex vivo extracts and high‐resolution NMR spectroscopy and are quantified in the metastatic tumor line, MDA‐mb‐231. Also reported is the quantification of cytosolic and lipid metabolites in breast cells of differing cancer phenotype, and the identification of metabolites that differ among these cell lines. In cell extracts, PCho and the PtdCho breakdown products, lysophosphatidylcholine, GPC and glycerol 3‐phosphate, are all raised in breast cancer lines relative to an immortalized non‐malignant line. These metabolic differences are in direct agreement with differences in expression of genes encoding enzymes in the choline metabolic pathway. Results of this study are consistent with previous studies, which have concluded that increased choline uptake, increased choline kinase activity, and increased phosholipase‐mediated turnover of PtdCho contribute to the observed increase in PCho in breast cancer. In addition, this study presents evidence suggesting a specific role for phospholipase A2‐mediated PtdCho catabolism. Gene expression changes following taxane therapy are also reported and are consistent with previously reported changes in choline metabolites after the same therapy in the same tumor model. Copyright © 2008 John Wiley & Sons, Ltd.
A face‐based smoothed finite element method (FS‐FEM) for 3D linear and geometrically non‐linear solid mechanics problems using 4‐node tetrahedral elements
Authors: Nguyen‐Thoi T. , Liu G. R. , Lam K. Y. , Zhang G. Y. 
Published: November 2008

AbstractThis paper presents a novel face‐based smoothed finite element method (FS‐FEM) to improve the accuracy of the finite element method (FEM) for three‐dimensional (3D) problems. The FS‐FEM uses 4‐node tetrahedral elements that can be generated automatically for complicated domains. In the FS‐FEM, the system stiffness matrix is computed using strains smoothed over the smoothing domains associated with the faces of the tetrahedral elements. The results demonstrated that the FS‐FEM is significantly more accurate than the FEM using tetrahedral elements for both linear and geometrically non‐linear solid mechanics problems. In addition, a novel domain‐based selective scheme is proposed leading to a combined FS/NS‐FEM model that is immune from volumetric locking and hence works well for nearly incompressible materials. The implementation of the FS‐FEM is straightforward and no penalty parameters or additional degrees of freedom are used. The computational efficiency of the FS‐FEM is found better than that of the FEM. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation of antimicrobial sutures by preirradiation grafting onto polypropylene monofilament
Authors: Gupta Bhuvanesh , Jain Rachna , Singh Harpal 
Published: November 2008

AbstractAntimicrobial sutures were prepared by the radiation grafting of acrylonitrile monomer onto polypropylene (PP) monofilament. The grafted sutures were subsequently hydrolyzed to transform nitrile groups into carboxylic groups for the immobilization of antimicrobial drug, tetracycline hydrochloride (TC). The modified sutures show continuous release of drug for a period of 4–5 days. The antimicrobial activity of the sutures was determined against both Gram positive and Gram negative bacteria by the zone of inhibition technique. Zone of inhibition was observed around the drug‐containing sutures in the plate inoculated with Escherichia coli (E. coli), Klebsiella pneumonea (K. pneumonea), and Staphylococcus aureus (S. aureus). The results of infection studies in albino rats against S. aureus showed no infection even after fourth postoperative day of surgery. This is because of the release of the TC drug at the site of injury, which inhibits the bacterial growth. Copyright © 2008 John Wiley & Sons, Ltd.
Model of the influence of energetic disorder on inter‐chain charge carrier mobility in poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylene vinylene]
Authors: Toman Petr , Nešpůrek Stanislav , Weiter Martin , Vala Martin , Sworakowski Juliusz , Bartkowiak Wojciech , Menšík Miroslav 
Published: November 2008

AbstractThe theoretical model of the inter‐chain charge carrier mobility in poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylene vinylene] (MEH–PPV) doped with polar additive is put forward. The polymer chain states of a charge carrier were calculated by means of diagonalization of a tight‐binding Hamiltonian, which includes disorder in both the local energies and transfer integrals. Consequently, the inter‐chain charge carrier transport is taking place on a spatially and energetically disordered medium. Because it is believed that the additive does not significantly influence the polymer supramolecular structure, the polymer conformations were simplified as much as possible. On the other hand, the energetic disorder is rigorously described. The transfer rates between the polymer chains were determined using the quasi‐classical Marcus theory. The model considered the following steps of the charge carrier transport: the charge carrier hops to a given polymer chain. Then, the charge carrier thermalizes to the Boltzmann distribution over all its possible states on this chain. After that, the charge carrier hops to any possible state on one of the four nearest neighboring chains. The results showed that the inter‐chain charge carrier mobility is very strongly dependent on the degree of the energetic disorder. If the energetic disorder is doubled from 0.09 to 0.18 eV, the mobility decreases by two or three orders of magnitude. Copyright © 2008 John Wiley & Sons, Ltd.
Dye, fluorophores and pigment coloration of nanofibers produced by electrospinning
Authors: Fantini Diego , Costa Luigi 
Published: November 2008

AbstractPolymeric nanofibers produced by the electrospinning technique are widely used in industrial scale production. Nanofibers chiefly find applications in filtration media and active–barrier surfaces for medical, biological, and military applications. In such applications, the quantity and the uniformity of the nanofibers distribution play a leading role in the product characteristics. For this reason, there is considerable interest regarding the nanofibers recovering quantification and simplification of the qualitative analysis. With the aim to improve and simplify the nanofibers relevability, a coloration approach for nanofibers has been designed and tested. The coloration has been carried out by organic dyes, pigments, and organic fluorophores and the consequent nanofibers' color has been analyzed by optical analysis, colorimetry, and spectroscopy. The coloration obtained by different dyes has been compared and their effect on the nanofibers relevability has been investigated. Moreover, the leading role of the light scattering phenomenon on the nanofiber coloration efficacy has been investigated by comparing the coloration response of nanofibers and film samples on equal terms of dye content. The study has been carried out using polyamide‐6 (PA6) as the testing polymer but the recovering quantification, the coloration approach, and the interaction between light and nanofibers can be extended to all the electrospinnable polymers. Copyright © 2008 John Wiley & Sons, Ltd.
Delivery systems for some biologically active 1,2,4‐triazine derivatives: synthesis and release
Authors: Salahuddin N. A. , El‐Barbary A. A. , Abdo N. I. 
Published: November 2008

AbstractTriazine‐loaded polymer microparticles composed of cross‐linked polymethylmethacrylate (PMMA) have been prepared. A series of PMMA cross‐linked polymers were prepared from methylmethacrylate (MMA) and divinylbenzene (DVB) by suspension polymerization using different percentages of solvents and cross‐linkers. Biologically active compounds including 4‐amino‐6‐substituted‐3‐thioxo‐3,4‐dihydro‐2H‐5‐oxo (or thioxo)‐1,2,4‐triazines (I–IV) were prepared and reacted with PMMA. Since optimization of the polymer delivery system is required to improve clinical applications, the effect of surface area, cross‐linker percentage on the loading, and release of triazines were studied. Alkaline conditions seem to favorably affect triazine release. Triazine hydrochlorides were ion exchanged with sodium montmorillonite (Na‐MMT). X‐ray diffraction (XRD) analysis confirms the intercalation of triazines between the layers of MMT. The presence of mineral domains with an average size of 33 nm was observed by transmission electron microscopy (TEM). The release of triazine compounds is more controllable in intercalated layered silicates. Copyright © 2008 John Wiley & Sons, Ltd.
Properties of methyltetrahydrophthalic anhydride‐cured epoxy resin modified with MITU
Authors: He S. J. , Shi K. Y. , Guo X. Z. , Du Z. J. , Zhang B. L. 
Published: November 2008

AbstractMethylimidazole‐terminated chain‐extended urea (MITU) containing polypropylene oxide spacer was synthesized and employed to modify epoxies composed of a diglycidyl ether of bisphenol‐A (E‐51) and methyltetrahydrophthalic anhydride (MTHPA). The curing behavior, viscoelastic property, impact response, and fracture surface morphology of the curing systems were systematically investigated. Differential scanning calorimeter (DSC) analysis reveals that the curing reactivity of the epoxy system is greatly enhanced with the addition of MITU. From the dynamic mechanical analysis, besides the low‐temperature β relaxation, shoulder at higher temperature side appears for the MITU‐modified systems. Meanwhile, the addition of MITU leads to the increase of loss factor (tan δ) over the temperature range of 0–75°C. Impact tests show that the modifier can be effective in toughening the epoxy resin at relatively low loading, and the scanning electron microscope (SEM) images of the fracture surface for the modified systems display signs of ductility. Copyright © 2008 John Wiley & Sons, Ltd.
Formation of clay intercalates with organic bilayers in hydrocarbon polymers
Authors: Galimberti Maurizio , Senatore Stanislao , Conzatti Lucia , Costa Giovanna , Giuliano Gaetano , Guerra Gaetano 
Published: November 2008

AbstractThe formation of clay intercalates with three different kinds of organic ammonium salts, when mixed in the presence of synthetic or natural polyisoprene rubber, has been investigated. X‐ray diffraction and transmission electron microscopy (TEM) experiments have shown that intercalates with organic bilayers, rather than with interdigitated organic monolayers, are obtained only for the ammonium salts presenting two long alkyl chains and only in the presence of the natural rubber (NR). These results have been qualitatively rationalized on the basis of suitable interlayer densities. Both monolayer and bilayer clay intercalates remain stable for short‐term heating procedures at temperatures lower than 250°C. For treatments at higher temperatures, where the decomposition of the organic ammonium salt occurs, both kinds of clay intercalates maintain intralayer crystalline order. However, the decomposition of the organic modifier leads to the formation of pristine and exfoliated clay for the intercalates with organic monolayers and bilayers, respectively. Copyright © 2008 John Wiley & Sons, Ltd.
Polydimethylsiloxane–cristobalite composite adhesive system for aerospace applications
Authors: Ansari Seema , Varghese Justin M. , Dayas K. R. 
Published: November 2008

AbstractThe effect of phase‐pure cristobalite (a high temperature crystalline polymorph of silica) on the adhesive characteristics of hydroxyl terminated polydimethylsiloxane (PDMS) was studied. The potential advantages of PDMS/cristobalite composite system as an adhesive for aerospace applications are also discussed. A PDMS/cristobalite composite adhesive system containing different filler contents (0–46 volume percentage, vol%) was prepared. The filler material, phase‐pure cristobalite, was synthesized by the pyrolysis of fused silica at 1400°C. The mechanical, rheological, and thermal characteristics of the composites were studied. A high yield stress (0.151 Pa), shear‐thinning index (1.051), and fast recovery rate were observed for ∼34 vol% cristobalite loading, which indicate that PDMS retains its excellent adhesive and flow characteristics even at high filler loading with enhanced mechanical characteristics. Thermal analysis shows the onset of degradation of PDMS shifts to higher temperatures, 372–438°C and 317–417°C in nitrogen and air atmosphere respectively, which shows excellent thermal stability. The residual component yields after thermal degradation of PDMS/cristobalite composite system in nitrogen and air atmosphere show different degradation mechanisms. Copyright © 2008 John Wiley & Sons, Ltd.