bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Modeling of the Phase Separation Dynamics in Blends of Reactive Monomers
Authors: Yandek Gregory R. , Kyu Thein 
Published: June 2005

AbstractSummary: Experimental observations of the dynamics of phase behavior for blends of reactive constituents, i.e. diglycidyl ether of bisphenol A (DGEBA), curing agent methylene dianiline (MDA), and a reactive liquid rubber (R45EPI), have been theoretically modeled by coupling system thermodynamics governed by a summation of the free energies of mixing and network elasticity with reaction kinetics and diffusion equations. Snap‐shots of the temporal evolution of ternary phase diagrams have been established based on the self‐condensation reactions of DGEBA‐MDA and R45EPI as well as a cross‐reaction between the two constituents forming a copolymer. Numerical solution of the proposed mean‐field model provides good qualitative agreement with experimental results, namely, the observance of phase separation followed by a phase dissolution and subsequent secondary segregation in a 50/25.4/50 DGEBA/MDA/R45EPI mixture, as well as a single gradual phase separation in a 70/25.4/30 mixture. The phase separation dynamics are explained by a competition between the growth in molecular weights of the reactive species rendering the systems towards instability, and the formation of copolymer acting to compatibilize the mixtures.Theoretical phase diagram for a DGEBA/MDA/R45EPI system.magnified imageTheoretical phase diagram for a DGEBA/MDA/R45EPI system.
Interface Structure between Immiscible Reactive Polymers under Transreaction: a Monte Carlo Simulation
Authors: He Xuehao , Nagel Jürgen , Lehmann Dieter , Heinrich Gert 
Published: June 2005

AbstractSummary: The interface structure between two immiscible melts, a polycondensate polymer A (e.g., polycarbonate, polyester or polyamide) and a polymer B, was studied by means of Monte Carlo simulations using the bond fluctuation model. Polymer B contained a reactive end group (e.g., OH, NH2 or COOH). Copolymers were generated in‐situ at the interfaces by transreactions (alcoholysis, aminolysis or acidolysis), composing of various length of block A, depending on the position of transreaction in the polycondensate chain A. The content of copolymer at the interface increased with the time, particular fast at the early stage. Fragments of polymers A were released with an end group, reactive to polymers A. This resulted in the proceeding of internal transreactions. An asymmetric interface structure was formed. The simulation also showed that copolymers generated by interfacial transreactions increased the compatibility of the two polymers and enhanced the adhesion strength at the interfaces.
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Muscle‐fiber apoptosis in neuromuscular diseases
Authors: Tews Dominique S. 
Published: June 2005

AbstractMuscle‐fiber loss is a characteristic of many progressive neuromuscular disorders. Over the past decade, identification of a growing number of apoptosis‐associated factors and events in pathological skeletal muscle provided increasing evidence that apoptotic cell‐death mechanisms account significantly for muscle‐fiber atrophy and loss in a wide spectrum of neuromuscular disorders. It became obvious that there is not one specific pathway for muscle fibers to undergo apoptotic degradation. In contrast, certain neuromuscular diseases seem to involve characteristic expression patterns of apoptosis‐related factors and pathways. Furthermore, there are some characteristics of muscle‐fiber apoptosis that rely on the muscle fiber itself as an extremely specified cell type. Multinucleated muscle fibers with successive muscle‐fiber segments controlled by individual nuclei display some specifics different from apoptosis of mononucleated cells. This review focuses on the expression patterns of apoptosis‐associated factors in different primary and secondary neuromuscular disorders and gives a synopsis of current knowledge. Muscle Nerve, 2005
Cardiac involvement in muscular dystrophies: Molecular mechanisms
Authors: Goodwin Fiona C. , Muntoni Francesco 
Published: June 2005

AbstractIn this review, we draw attention to the multiple mechanisms responsible for the pathogenesis of cardiomyopathies in patients with muscular dystrophies. More than one single mechanism is likely to be involved in the development of skeletal and cardiac muscle pathology even when there is a single protein defect. The best example is dystrophin deficiency, in which increased sarcolemmal permeability following eccentric exercise, reduced force generation, and abnormal signaling are all likely to contribute to the progressive muscle damage observed. In other conditions, such as the sarcoglycanopathies, a protein deficiency both in the striated cardiomyocte and the vascular smooth muscle appears to play a significant role. An entirely different mechanism of disease is likely in defects of nuclear envelope proteins, although the precise pathogenesis of this group of conditions is still not clear. Differences between the organization of skeletal and cardiac muscle protein complex are also only starting to emerge and will very likely be the focus of future research. Muscle Nerve, 2005
Motor unit action potential topography and its use in motor unit number estimation
Authors: Blok Joleen H. , van Dijk Johannes P. , Zwarts Machiel J. , Stegeman Dick F. 
Published: June 2005

AbstractHigh‐density multichannel electromyography (EMG) recordings add spatial information to the temporal information content of the surface EMG (sEMG) signal. This study explores the potential value of such multichannel information at a single motor unit level, in particular for the improvement of motor unit number estimation (MUNE) techniques. It is shown that multichannel recordings make it easier to distinguish motor unit action potentials (MUAPs) and that MUAP combinations can be better resolved. Furthermore, the spatiotemporal information allows a quantitative assessment of the representativity of the mean of the recorded MUAPs in relation to the maximum CMAP, i.e., for the muscle as a whole. In general, this is practically impossible on the basis of temporal information alone. For these reasons, we expect that high‐density sEMG has the potential to address several methodological limitations of single channel surface EMG recordings. This is specifically illustrated in this study for one of the MUNE techniques in use, the F‐response method. Muscle Nerve, 2005
Spastic muscle properties are affected by length changes of adjacent structures
Authors: Smeulders Mark J. C. , Kreulen Michiel , Hage J. Joris , Huijing Peter A. , van der Horst Chantal M. A. M. 
Published: June 2005

AbstractRecent animal experiments have shown that up to 37% of muscle force may be transmitted to adjacent structures rather than reach the insertion of the muscle's tendon, and that the extent of such force transmission depends on the length and relative position of these structures. We tested whether the force–length characteristics of the distally tenotomized human flexor carpi ulnaris muscle (FCU) of nine patients with cerebral palsy varied with the change of relative length of adjacent structures induced by a change of wrist position. In four patients, the FCU exerted up to 40% more active force in a flexed wrist position at short FCU length, whereas the active force was not significantly higher in the other five. In the same manner, passive force–length characteristics of the spastic FCU changed upon changes in wrist position. Variability in myofascial force transmission may partly explain the variability in success of the FCU‐transfer. Muscle Nerve, 2005
Neuropathology of paraneoplastic neuropathy with anti‐disialosyl antibody
Authors: Kobayashi Michio , Kato Kazumaro , Funakoshi Kei , Watanabe Sumio , Toyoshima Itaru 
Published: June 2005

AbstractWe report a paraneoplastic neuropathy with severe motor involvement following sensory‐ataxic disturbance. Anti‐disialosyl immunoglobulin M (IgM) antibody was detected in the course of malignant lymphoma of diffuse large B‐cell type, which usually spares the motor system. Onset was subacute, with relapsing and remitting sensory ataxia, muscle weakness, bulbar palsy, respiratory paralysis, and ophthalmoplegia; only neck rotation was retained in the terminal stage. Autopsy showed no lymphoma cells infiltrating the nervous system. Motor neurons survived in the spinal cord, but mean diameter of the ventral spinal nerve roots was reduced considerably. The gracile fasciculus and the sural nerve were more markedly degenerated than proximal portions. Morphometric study showed that most of the proximal motor and sensory axons did not extend distally. This autopsy report provides further definition of a neuropathy associated with malignant lymphoma and IgM antibodies against disialosyl residues. Muscle Nerve, 2005
A counterfort versus a cantilever retaining wall—a seismic equivalence
Authors: Chugh Ashok K. 
Published: June 2005

AbstractA procedure is presented to develop geometric dimensions and material property values for a model cantilever wall from those of a prototype counterfort wall such that the model wall will simulate the response of the prototype wall for seismic loads. The equivalency criteria are given. A sample problem is included to illustrate the use of the proposed procedure. Accuracy of results is discussed. Published in 2005 by John Wiley & Sons, Ltd.
Secondary Burkitt lymphoma in a retinoblastoma patient with 13q deletion syndrome
Authors: Hongeng Suradej , Parapakpenjun Surapan , Pakakasama Samart , Rerkamnuaychoke Busaba , Pornkul Ratanaporn 
Published: May 2005

AbstractWe report a boy with constitutional deletion 13q chromosome associated with dysmorphic features and bilateral retinoblastoma. The patient developed secondary Burkitt lymphoma 5 years after the diagnosis of retinoblastoma at the age of 8 months. He has completed treatment for both malignancies. At present, he is 7 years old and still in remission. Pediatr Blood Cancer 2006,46:524–526. © 2005 Wiley‐Liss, Inc.
Multicentric osteosarcoma presenting as retrobulbar mass: A diagnostic enigma
Authors: Wong K.F. , Shu S.J. , Luk I.S.C. , Yuen H.L. , Leung J.N.S. , Chan J.K.C. 
Published: May 2005

AbstractOsteosarcoma is the most common primary malignant bone tumor of children and adolescents. It often presents as a solitary lesion; multicentric osteosarcoma with synchronous lesions occurring at multiple skeletal sites is very rare. We report a 9‐year‐old boy with multicentric osteosarcoma who presented with a left retrobulbar non‐sclerotic mass. The multiple lesions in bone were mostly non‐sclerotic on radiological examination except for a single lesion in the left tibia. Biopsy of the retrobulbar mass showed an unclassifiable poorly differentiated malignant tumor. Marrow aspiration smears showed many large, often segregated, round cells that expressed NB84a. However, trephine biopsy showed the formation of tumoral osteoid by the malignant cells, finally permitting the definitive diagnosis of osteosarcoma to be made. A hypertetraploid clone with complex structural abnormalities was demonstrated by cytogenetic study. © 2005 Wiley‐Liss, Inc.
Free volume and the physico‐mechanical behaviour of polyurethane/polyacrylonitrile interpenetrating polymer networks: positron annihilation results
Authors: Kumar H , Siddaramaiah  , Kumaraswamy GN , Ravikumar HB , Ranganathaiah C 
Published: June 2005

AbstractA series of semi‐interpenetrating polymer networks (SIPNs) of polyurethane (PU) and polyacrylonitrile (PAN) in the weight ratios 90/10, 70/30, 60/40 and 50/50 PU/PAN were prepared using polyethylene glycol, 4,4′‐diphenylmethane diisocyanate and acrylonitrile by sequential polymerization. Differential scanning calorimetry and scanning electron microscopy techniques were used to find the glass transition temperature and surface morphology of SIPNs. The tough and transparent SIPN films were characterized for physico‐mechanical properties such as density, surface hardness and tensile properties. Positron annihilation lifetime spectroscopy (PALS) was used to measure the free volume behaviour of the IPNs. The sorption behaviour of IPNs with benzene penetrant was also measured. An attempt was made to correlate the PALS results with the mechanical and sorption properties of the SIPNs. Copyright © 2005 Society of Chemical Industry
Spatial and temporal evolution of the photo initiation rate for thick polymer systems illuminated on both sides
Authors: Stephenson Nicole , Kriks Dane , El‐Maazawi Mohamed , Scranton Alec 
Published: June 2005

AbstractPhotopolymerizations of thick systems are inherently non‐uniform and much more complex than polymerizations of films and coatings. This contribution presents a mathematical description of the evolution of the photoinitiation rate profile for a thick photopolymerization system illuminated on two sides. Simulation results revealed that when two lamps of equal intensity are used, the spatial and temporal evolution of the photoinitiation rate profile follows a characteristic progression from a bimodal distribution to a unimodal shape with a maximum in the center of the sample. The addition of a second light source can lead to an initiation profile that is more uniform throughout the sample. System variables such as the initiator concentration, molar absorptivity and monomer absorptivity determine how the photoinitiation rate profile evolves. For example, increasing initiator concentration results in sharper initiation fronts which move through the sample more slowly. A reflective boundary condition, a special case of two‐sided illumination using only one lamp, was found to enhance the initiation rate and uniformity for some reaction systems. This model provides the fundamental understanding needed to ensure proper selection of reaction components for effective photoinitiation in thick systems, including the possibility of a second light source as an additional design variable. Copyright © 2005 Society of Chemical Industry
Synthesis and characterization of homo‐ and copolymers of 3‐(2‐cyano ethoxy)methyl‐ and 3‐[methoxy(triethylenoxy)]methyl‐3′‐methyl‐oxetane
Authors: Ye Lin , Feng Zeng‐guo , Su Yue‐feng , Wu Feng , Chen Shi , Wang Guo‐qing 
Published: June 2005

AbstractTwo oxetane‐derived monomers 3‐(2‐cyanoethoxy)methyl‐ and 3‐(methoxy(triethylenoxy)) methyl‐3′‐methyloxetane were prepared from the reaction of 3‐methyl‐3′‐hydroxymethyloxetane with acrylonitrile and triethylene glycol monomethyl ether, respectively. Their homo‐ and copolyethers were synthesized with BF3· Et2O/1,4‐butanediol and trifluoromethane sulfonic acid as initiator through cationic ring‐opening polymerization. The structure of the polymers was characterized by FTIR and1H NMR. The ratio of two repeating units incorporated into the copolymers is well consistent with the feed ratio. Regarding glass transition temperature (Tg), the DSC data imply that the resulting copolymers have a lower Tg than pure poly(ethylene oxide). Moreover, the TGA measurements reveal that they possess in general a high heat decomposition temperature. The ion conductivity of a sample (P‐AN 20) is 1.07 × 10−5 S cm−1 at room temperature and 2.79 × 10−4 S cm−1 at 80 °C, thus presenting the potential to meet the practical requirement of lithium ion batteries for polymer electrolytes. Copyright © 2005 Society of Chemical Industry
Francisella tularensis live vaccine strain: Proteomic analysis of membrane proteins enriched fraction
Authors: Pávková Ivona , Hubálek Martin , Zechovská Jana , Lenčo Juraj , Stulík Jiří 
Published: June 2005

AbstractProteome analysis of Gram‐negative facultative intracellular pathogen Francisella tularensis (F. tularensis) live vaccine strain has been performed only on whole‐cell extracts so far. This is the first study dealing with the analysis of the membrane subproteome of this microorganism. A fraction enriched in membrane proteins obtained by carbonate extraction was separated using two‐dimensional electrophoresis and all visualized spots were identified by mass spectrometry. The reference map is the basis for further comparative analyses of virulent and non‐virulent F. tularensis strains.
Lipase‐catalyzed ring‐opening polymerization of 6(S)‐methyl‐morpholine‐2,5‐dione
Authors: Feng Yakai , Klee Doris , Höcker Hartwig 
Published: June 2005

AbstractLipase‐catalyzed ring‐opening bulk polymerizations of 6(S)‐methyl‐morpholine‐2,5‐dione (MMD) were investigated. Selected commercial lipases were screened as catalysts for MMD polymerization at 100 °C. Polymerizations catalyzed with 10 wt % porcine pancreatic lipase type II crude (PPL), lipase from Pseudomonas cepacia, and lipase type VII from Candida rugosa resulted in MMD conversions of about 75% in 3 days and in molecular weights ranging from 8200 to 12,100. Poly(6‐methyl‐morpholine‐2,5‐dione) [poly(MMD)] had a carboxylic acid group at one end and a hydroxyl group at the other end. However, lipase from Mucor javanicus showed lower catalytic activity for the polymerization. During the polymerization, racemization of the lactate residue took place. PPL was selected for further studies. The rate of polymerization increased with increasing PPL concentration under otherwise identical conditions. When the PPL concentration was 5 or 10 wt % with respect to MMD, a conversion of about 70% was reached after 6 days or 1 day, respectively, whereas for a PPL concentration of 1 wt %, the conversion was less than 20% even after 6 days. High concentrations of PPL (10 wt %) resulted in high number‐average molecular weights (<3 days); with a lower concentration of PPL, lower molecular weight poly(MMD) was obtained. The concentration of water was an important factor that controlled not only the conversion but also the molecular weight. With increasing water content, enhanced polymerization rates were achieved, whereas the molecular weight of poly(MMD) decreased. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3030–3039, 2005
Novel photocurable monomers: The synthesis of difunctional vinyl ethers with a phosphonate group and difunctional 1‐propenyl ethers with a phosphonate group and their photoinitiated cationic polymerization
Authors: Minegishi Shouji , Otsuka Tetsurou , Kameyama Atsushi , Nishikubo Tadatomi 
Published: June 2005

AbstractPhosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were prepared by the regioselective addition reaction of glycidyl vinyl ether (GVE) or 1‐propenyl glycidyl ether with diaryl phosphonates with quaternary onium salts as catalysts. The reaction of GVE with bis(4‐chlorophenyl) phenylphosphonate gave bis[1‐(4‐chlorophenoxy methyl)‐2‐(vinyloxy)ethyl]phenylphosphonate in a 68% yield. The structures of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were confirmed by IR and 1H NMR spectra and elemental analysis. Photoinitiated cationic polymerizations of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were investigated with photoacid generators. The polymerization of vinyl ether groups and 1‐propenyl ether groups of the obtained monomers proceeded very smoothly with a sulfonium‐type cationic photoinitiator, bis[4‐(diphenylsulfonio)phenyl]sulfide‐bis(hexafluorophosphate), upon UV irradiation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3105–3115, 2005
Synthesis and characterization of novel biodegradable epoxy‐modified polyurethane elastomers
Authors: Yeganeh Hamid , Lakouraj Moslem Mansour , Jamshidi Sadegh 
Published: June 2005

AbstractBiodegradable polyurethane elastomers with the potential for applications in medical implants were synthesized from the reaction of epoxy‐terminated polyurethane prepolymers (EUPs) with 1,6‐hexamethylenediamine as a curing agent. EUPs were themselves prepared from the reaction of glycidol and isocyanate‐terminated polyurethanes made from different molecular weights of poly(ε‐caprolactone) (CAPA) and 1,6‐hexamethylene diisocyanate. All materials were characterized by spectroscopic methods. The curing conditions were optimized by gel content measurements. The curing kinetic and kinetic parameters were determined from differential scanning calorimetry measurements. The effects of changing the crosslink density and crystallinity of elastomers via the alteration of the CAPA polyol molecular weight on the physical, mechanical, and degradation properties of the final elastomeric polymers were examined fully. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2985‐2996, 2005
Synthesis and characterization of side‐chain liquid‐crystalline polymers and study of their role in the crystallization of high‐density polyethylene
Authors: Qiao Wen‐Qiang , Fan Xiao‐Dong , Kong Jie , Xie Yun‐Chuan , Si Qing‐Fa , Wang Sheng‐Jie , Liu Yu‐Yang 
Published: June 2005

AbstractSide‐chain liquid‐crystalline polymers (SCLCPs) as nucleating agents for high‐density polyethylene (HDPE) were investigated. For this purpose, the molecular architectures of four different vinyl monomers with liquid‐crystalline properties were designed and prepared with 1‐butanol, 1‐pentanol, 4‐hydroxybenzoic acid, hydroquinone, and acryloyl chloride as the starting materials through alkylation and acylation reactions. The corresponding polymers were synthesized by homopolymerization in 1,4‐dioxane with benzoyl peroxide as the initiator at 60 °C. Both the monomers and the synthesized polymers were characterized with elemental analysis, Fourier transform infrared, and 1H NMR measurements. Differential scanning calorimetry, thermogravimetric analysis, and hot stage polarized optical microscopy were employed to study the phase‐transition temperature, mesophase texture, and thermal stability of the liquid‐crystalline polymers. The results showed that all the polymers had thermotropic liquid‐crystalline features. Being used as nucleating agents, SCLCPs effectively increased both the crystallization temperature and rate and, at the same time, raised the crystallinity for HDPE. In comparison with common small‐molecule nucleating agents, such as 1,3:2,4‐dibenzylidenesorbitol, SCLCPs are more efficient and are indeed excellent nucleating agents for HDPE. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3067–3078, 2005
Highly conductive soluble terpolymers of aniline, toluidine, and o‐aminobenzoic acid/m‐aminobenzenesulfonic acid
Authors: Savitha P. , Sathyanarayana D. N. 
Published: June 2005

AbstractTwo series of terpolymers, one of o‐/m‐toluidine and aniline with o‐aminobenzoic acid and the other of o‐/m‐toluidine and aniline with m‐aminobenzenesulfonic acid, have been synthesized by oxidative polymerization via an emulsion method with ammonium persulfate as the oxidant and HCl as the external dopant. The terpolymers exhibit excellent solubility and retain the high conductivity (∼1 S cm−1) characteristic of the unsubstituted homopolymer, polyaniline. The terpolymers also possess higher thermal stability than polyaniline. This can be attributed to the presence of internal doping groups and substituents, which introduce flexibility to the otherwise rigid polyaniline backbone. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3040–3048, 2005