bluuebunny/crossref_metadata_2025 huggingface dataset:
Cover Picture: Macromol. Mater. Eng. 6/2006
Authors: Tang Huaiguo , Qi Qing , Wu Youping , Liang Guihua , Zhang Liqun , Ma Jun
Published: June 2006

Cover: The picture on the cover shows the reinforcement effect of starch on the mechanical properties and thermal property of styrene‐butadiene‐rubber. With mechanical strength comparable to carbon black, the reinforced rubber has the advantage of low dynamic heat rise and the renewable starch source. Further details can be found in the article by H. Tang, Q. Qi, Y. Wu, G. Liang, L. Zhang,* and J. Ma* on page 629.
Cover Picture: Macromol. Symp. 239/2006
Authors: Kaminsky W. , Funck A. , Wiemann K.
Published: June 2006

Cover: Advancement in modern po lymer technologies such as photo‐electronics, pharmaceutical and biomedical fields, biodegradable systems and specific composites are increasingly interrelated. Urgent demands are apparent for new, eco‐efficient, advanced polymer systems, the development of which requires interdisciplinary knowledge. The common thinking of scientists specialized in certain segments of polymer science and technology was strongly initiated by the 8th International Symposium on Polymers for Advanced Technologies (PAT 2005) held in Budapest, September 2005.

Convergent concepts can be seen in the developments of materials to be used as pharmaceuticals, biomaterials, polymer composites, fire retarded polymers, membranes, conductive systems and fuel cells. The presented unusual ways for various technologies of advanced polymer systems may initiate further research activities in the near future.

Responding to the demand for better understanding of the advanced materials the conference covered the mechanistic and technological aspects of syntheses, composite and nanocomposite formation, and behaviour of polymeric materials in biomedical environment. As an example, the picture shows an SEM micrograph of carbon nanofibers in sPP (filler content: 0,6 %), taken from the contribution by W. Kaminsky.
Nanocomposites by In Situ Polymerization of Olefins with Metallocene Catalysts
Authors: Kaminsky W. , Funck A. , Wiemann K.
Published: June 2006

Nanoparticles such as silica balls (monopheres), calcium carbonate, carbon nanotubes (CNT) or fibers (CF) are uniformly coated with a film of polyolefins of variable thickness using metallocene/methyl‐aluminoxane (MAO) catalysts. The catalyst is adsorbed on the filler surface, leading to a polymer growth directly on its surface. Highly filled and stiff nano composites, basing on polyethene (PE) and syndiotactic or isotactic polypropene (sPP/iPP) with a content up to 85 wt% of silica or 7 wt% of multi‐walled carbon nanotubes (MWCNT) are obtained. MWCNT treated with MAO in the same way form a heterogenous cocatalyst for the preparation of iso‐ and syndiotactic PP/MWCNT composites, too. The uniformity of the dispersion depends primarily on the pretreatment of the filler.
Smart Reactivity in Gelatine/PNIPAM Mixtures: Control of the Cross‐Linking and Microheterogeneities
Authors: Boudet C. , Iliopoulos I. , Monti F. , Cloitre M. , Poncelet O.
Published: June 2006

Chemical cross‐linking of gelatine was achieved by using a thermo‐sensitive reactive poly(N‐isopropylacrylamide) as a cross‐linker. The reaction occurs only below the LCST. Controlled micro‐heterogeneities were created inside the gel without macroscopic volume transition. Acceleration of the drying process indicates faster water diffusion in the micro‐heterogeneous gel.
Swelling Behavior of N‐t‐butylacrylamide Copolymer and Terpolymers
Authors: Kaçmaz Ayşecik , Gürdağ Gülten
Published: June 2006

Copolymers and terpolymers of N‐t‐butylacrylamide (TBA) with 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) and N‐hydroxy methyl acrylamide (NHMAAM) were prepared by solution polymerization in a 1:1 (v/v) mixture of methanol and water at 50 °C keeping the TBA content in the feed constant at 60% based on mole ratio. The contents of AMPS or NHMAAM used for the preparation of TBA‐AMPS and TBA‐NHMAAM copolymers were 40 mole %. Molar percentages of AMPS and NHMAAM monomers in the feed for the preparation of TBA‐AMPS‐NHMAAM terpolymers were varied as 10:30, 20:20, and 30:10, respectively. The effects of temperature, AMPS and crosslinker contents, and the drying of swollen gels on the swelling behavior of ionic and non‐ionic TBA gels were investigated in distilled water between 10–50 °C and in buffer solutions having various pHs (1.9, 3.1, 5.6, 7.1, and 9.8) with constant ionic strength of 0.08 M at 20 °C using both the dry and the swollen forms of gels. The chemical structures and microscopic morphologies of the polymers were investigated by FTIR and SEM, respectively.
Molecular Dynamics of PGA Bioabsorbable Polymer During Isothermal Cold Crystallization
Authors: Kortaberria Galder , Jimeno Amaia , Arruti Puy , de la Caba Koro , Remiro Pedro , Eceiza Arantxa , Mondragon Iñaki
Published: June 2006

An investigation was carried out on the molecular dynamics of poly(glycolide) (PGA) in its completely amorphous state and during isothermal cold crystallization. Experimental results were generated over a wide range of frequency and temperature by broad‐band dielectric spectroscopy (DRS). The variation of the average relaxation time (defined as τ= ½πfmax where fmax is the frequency at maximum loss for the main α relaxation) has been studied during cold crystallization and the temperature dependence of this average relaxation time for completely amorphous and crystallized samples has been analyzed. This behaviour has been modelled by Havriliak‐Negami and Vogel‐Fulcher equations. The sensitiveness of the segmental dynamics to the degree of crystallinity has been analyzed, taking into account the relaxing segments and the amorphous layers between lamellae. Supporting evidence about the thermal behaviour of the polymers has been obtained with DSC. Complementarily, the evolution of the morphologies obtained during crystallization processes has been followed by optical microscopy.
Investigating the Time Dependent Behavior of Thermoplastic Polymers under Tensile Load
Authors: Vas László Mihály , Nagy Péter
Published: June 2006

The relationship between the results of the tensile and the stress relaxation tests of polypropylene specimens were analyzed and an attempt was made to find a way to estimate the former from the latter based on the measurements and the theory of linear viscoelasticity. The mechanical response of real polymers are basically of nonlinear character, therefore their behavior patterns do not meet the idealized (linear) ones. Experiments were performed on poly(propylene) (PP) as a test material and the stress relaxation behavior, as well as the linear elastic and linear viscoelastic approximation of the tensile load‐time curve were analyzed. To demonstrate the applicability of our idea and to perform the numerical calculations we have chosen a flexible function with three parameters to realize the nonlinear behavior.
Maleic Anhydride Polyethylene Octene Elastomer Toughened Polyamide 6/Polypropylene Nanocomposites: Mechanical and Morphological Properties
Authors: Hassan Azman , Othman Norhayani , Wahit Mat Uzir , Wei Lim Jian , Rahmat Abdul Razak , Mohd Ishak Zainal Ariffin
Published: June 2006

A series of polyamide 6/polypropylene (PA6/PP) blends and nanocomposites containing 4 wt% of organophilic modified montmorillonite (MMT) were designed and prepared by melt compounding followed by injection molding. Maleic anhydride polyethylene octene elastomer (POEgMAH) was used as impact modifier as well as compatibilizer in the blend system. Three weight ratios of PA6/PP blends were prepared i.e. 80:20, 70:30, and 60:40. The mechanical properties of PA6/PP blends and nanocomposite were studied through flexural and impact properties. Scanning electron microscopy (SEM) was used to study the microstructure. The incorporation of 10 wt% POEgMAH into PA6/PP blends significantly increased the toughness with a corresponding reduction in strength and stiffness. However, on further addition of 4 wt% organoclay, the strength and modulus increased but with a sacrifice in impact strength. It was also found that the mechanical properties are a function of blend ratio with 70:30 PA6/PP having the highest impact strength, both for blends and nanocomposites. The morphological study revealed that within the blend ratio studied, the higher the PA6 content, the finer were the POEgMAH particles.
Synthesis and Properties of Oligo‐/Polymers Based on a “Flexible” Swivel‐Cruciform Structure
Authors: Nehls Benjamin S. , Galbrecht Frank , Bilge Askin , Scherf Ullrich , Farrell Tony
Published: June 2006

We have introduced the concept of the so‐called swivel type cruciforms as a highly flexible tool to tune the molecular properties from amorphous to highly crystalline features. Simple alkoxy substituted binaphthyl building blocks have been introduced randomly into poly(9,9‐dioctylfluorene) (PFO) thereby suppressing the formation of side‐chain crystallization. On the other hand the all aryl penta‐thiophene based cruciform exhibited strong π–π interaction between the arms and gave one of the highest values reported to date for wet processed organic field effect transistors (OFETs) utilising oligothiophenes.
A Study on the Ballistic Performance of Composites
Authors: Faur‐Csukat Gabriella
Published: June 2006

The mechanical behaviour and ballistic performance of carbon, glass (E and S type), aramid and polyethylene fabric reinforced composites with different epoxy resins were studied. The specimens – produced by hand lay‐up method – were characterized by low velocity (Charpy and drop‐weight tests) and high velocity (two different calibre ballistic) impact tests. The energy absorption capacity of the composites was found to be strongly affected by the material properties of the reinforcing fiber, by the type of fabric structure and by the elasticity of resin.
Development and Analysis of New Filament Wound Composite Pipes Made of Glass Fiber Reinforced 3P Resin
Authors: Czél Gergely , Czigány Tibor
Published: June 2006

Filament wound composite pressure pipes made of newly developed 3P, various hybrid and reference resin materials and glass fiber filaments were investigated. 3P resins consist of soluble silicates, polyisocyanates and other additives, they are flame and chemical resistant, and capable of curing under wet conditions. Tensile strengths, tensile moduli and effective moduli values obtained from ring stiffness tests were evaluated. Properties of pipe types made of new resin materials were compared to those made of reference resins. A special tensile specimen fabricating process and a cross sectional area calculating method was presented. The calculation method is capable of handling the geometric inaccuracies of specimen prefabrication steps e.g. cutting. Evaluated material properties were discussed by defining dimensionless performance factors. Pipes were classified according to these performance factors and the suitability of the new resin materials for composite pressure pipe manufacturing was established. The best newly developed matrix materials were the 16905 type vinylester‐3P hybrid and 16907 type vinylester‐urethane hybrid resins, because of their outstanding mechanical properties.
Sol‐Gel Transition and Equilibrium Shear Modulus of Poly(vinyl chloride) and Plasticizers
Authors: Semsarzadeh M. A. , Barikani S. M.
Published: June 2006

The elasticity of poly(vinyl chloride) gels with molecular weight distribution (Mw/Mn), of 2.16 have been studied in the region beyond their gel points. Dynamic storage modulus G′, and equilibrium gel shear modulus of elasticity Ge, at low frequencies (ω) have specific developments as a function of polymer concentrations c, and plasticizers. The scaling elasticity from Ge = kεz equation holds at different PVC plasticizer gels. The scaling exponent z, and constant k. ε is defined as the relative distance, ε = (|c − cg|)/cg, the calculated z = 2.45 ± 0.15. Furthermore, this analysis provides constant k with certain informations about the dependency of gel elasticity on the kind of plasticizer. Near the sol‐gel transition temperature T, Ge decreases rapidly with increasing temperature. The normalized moduli GeM/cRT, of the gels at different temperature, and/or c were dependent on the relative distance from the gelation point ε, and PVC and plasticizers concentration respectively. These results suggested mesh size of gel network near the gelation point for PVC with bis(2‐ethylhexyl) phthalate (DOP) or di‐n‐butyl sebacate (DBS) plasticizers that has been newly reported.
Effect of Temperature on Dynamic Physical Behavior of Poly(vinyl chloride) Gel Structure with Ester Plasticizers
Authors: Semsarzadeh M. A. , Barikani S. M. , Ansari M.
Published: June 2006

Dynamic viscoelastic properties of poly(vinyl chloride) (PVC)/bis(2‐ethylhexyl) phthalate (DOP) and PVC/di‐n‐butyl sebacate (DBS) gels with molecular weight distribution (Mw/Mn), of 2.16 and various polymer concentrations c, have been studied as a function of temperature. These PVC gels exhibited an elastic solid at room temperature T, and gradually became liquid (sol) with increasing temperature. The sol‐gel transition took place at a critical gel temperature at which the scaling law of G′(ω) ∼ G″(ω) ∝ ωn held, allowing an accurate determination of the critical gel temperature by means of the frequency ω independence of the loss tangent. In this study the scaling exponent n, was 0.75–0.77. This is in good agreement with the previous results observed at different temperatures and suggests the formation of a similar fractal structure of the PVC gels. The gel strength Sg, at the gel point increased with increasing PVC concentration. These results suggest a unique character and structure for the gel points of PVC‐plasticizers.
Kinetics and Morphology of an Epoxy Resin Modified with PEO‐PPO‐PEO Block Copolymers
Authors: de la Caba Koro , Larrañaga Maider , Eceiza Arantxa , Corcuera Maria Angeles , Mondragon Inñaki
Published: June 2006

Block copolymers are a special class of polymers having the ability to self‐assemble into nanoscale ordered structures which depend on molecular composition of the blocks. With the aim of studying the influence of copolymer composition, the kinetics of a 4,4′‐diaminodiphenylmethane‐cured diglycidyl ether of bisphenol‐A (DGEBA) epoxy system modified with a PEO‐PPO‐PEO block copolymers has been investigated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR), taking into account the relation between blocks in the copolymer as well as different copolymer contents. DSC results show that the rate of cure reaction decreases when the copolymer is added, which can be attributed to the interaction between the hidroxyl groups of the growing epoxy thermoset and the ether groups of the block copolymer observed by FTIR. The experimental results obtained have been related to the morphologies observed by atomic force microscopy (AFM).
Preparation of a New Polymeric Surfactant for Emulsion Polymerization
Authors: Sarac Ayfer , Filiz Senkal B. , Yavuz Erdem , Gürsel Yesim Hepuzer
Published: June 2006

The stability of polymeric dispersions is a property of practical importance and hence, the search for an optimized strategy to equip polymer dispersions with sufficient stability is a matter of continuous research during the last years. The kernel is to reach a sufficient stability, as it is required during polymerization, conditioning, or storage and to allow coagulation or coalescence of particles when it is needed, such as during separation of polymer from latex or during film formation. In this study, the emulsion homopolymerization system containing vinyl acetate, potassium persulfate, new polymeric surfactant, NaHCO3 and water was studied in the classical glass emulsion polymerization reactor. The effects of new polymeric emulsifier on the physicochemical properties of obtained vinyl acetate latex properties were investigated depending on vinyl acetate percentage in homopolymerization.
Preparation of Aqueous Polyurethane Dispersions Using Aromatic Diisocyanate
Authors: Sugano Shunji , Chinwanitcharoen Charoen , Kanoh Shigeyoshi , Yamada Toshiro , Hayashi Shunichi , Tada Kaoru
Published: June 2006

Aqueous polyurethane dispersions were prepared by the reaction of hydroxyl‐terminated poly(ethylene adipate), ethylene glycol, dimethylol propionic acid and aromaic diisocyante, 4,4′‐diphenylmethane diisocyanate. The influence of molecular weight of oligoester and molar ratio between isocyanate and hydroxyl groups (NCO/OH) in the prepolymerization step were investigated. Molecular weight, particle size and particle size distribution were measured and compared. It was verified that the molecular weight increases with increasing in NCO/OH molar ratio. The results suggest that the hard segment content plays an important role in particle size and particle size distribution of the dispersions.
Synthesis and Characterization of Triblock Terpolymers with three Potentially Crystallisable Blocks: Polyethylene‐b‐poly(ethylene oxide)‐b‐poly(ε‐caprolactone)
Authors: Vivas M. , Contreras J. , López‐Carrasquero F. , Lorenzo A.T. , Arnal M.L. , Balsamo V. , Müller A.J. , Laredo E. , Schmalz H. , Abetz V.
Published: June 2006

A first attempt was made to produce novel ABC triblock terpolymers with three potentially crystallisable blocks: polyethylene (PE), poly(ethylene oxide) (PEO), and poly(ε‐caprolactone) (PCL). Polybutadiene‐b‐poly(ethylene oxide) diblock copolymers were synthesized by living anionic polymerization. Then, a non‐catalyzed thermal polymerization of ε‐caprolactone from the hydroxyl end group of the PB‐b‐PEO diblock precursors was performed. Finally, hydrogenation by Wilkinson catalyst produced PE‐b‐PEO‐b‐PCL triblock terpolymers. Side reactions were detected that lead to the formation of undesired PCL‐b‐PEO diblock copolymers, however, these impurities were successfully removed by purification. A range of triblock terpolymers with PCL and PEO minor components were prepared. Topological restrictions on the PEO middle block prevented this block from crystallizing while the complex crystallization behavior of the PE and PCL blocks was documented by DSC and WAXS measurements.
Π‐Conjugated Helical Nano‐Columnar Polyacetylenes as Novel Color Controllable Materials
Authors: Tabata Masayoshi , Mawatari Yasuteru , Sone Takeyuki , Miyasaka Atsushi , Kai Huang , Orito Kazuhiko , Sadahiro Yoshikazu
Published: June 2006

A series of p‐n‐alkoxyphenylacetylenes (pROPA)s (R: CnH2n+1, n = 1, 2, 4, 6, 8, 10, 12, and 14) was polymerized with [Rh(norbornadiene)Cl]2 catalyst in the presence of triethylamine to give stereoregular polyacetylenes, which colors of the resulting polymers were changed with increace of the carbon number of the alkyl side chains, i.e., yellow (n = 1∼6), orange (n = 8), red (n = 10), and dark red (n = 12, 14) along. Based on 1H NMR and laser Raman spectra, it was found that the main chain of these polymers was cis‐forms. Wide‐angle X‐ray diffraction (XRD) analysis indicated that yellow polymers were almost amorphous. In the case of the orange polymer, crystallinity, i.e., columnar content, was increased. Red and dark red polymers consisted largely of the columnar. It was concluded that colors of these polymers were strongly correlated with their columnar content. Therefore, the columnar of these stereoregular polyacetylenes can be considered as helical self‐assembly π‐conjugated , i.e., color controllable material.
Aliphatic Polyesters for Advanced Technologies – Structural Characterization of Biopolyesters with the Aid of Mass Spectrometry
Authors: Adamus Grażyna
Published: June 2006

Application of the ESI‐ mass spectrometry technique for the structural studies of biopoliesters is reported. The structural studies were performed on two selected commercially available biopolyesters i.e. poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH), contained up to 87% of PHB repeat units, with the aid of ESI‐MS analysis of the respective low molar mass oligomers. The molecular architecture of individual macromolecules, including the chemical structure of the end groups, composition and sequence distribution were determined based on mass‐resolved signals of ESI‐mass spectra of PHBH and PHBV oligomers. The general utility of MS characterization of biopoliester macromolecules at the molecular level has been demonstrated and supported by NMR analysis.
Characterization of Plasma‐Polymerized 4‐vinyl Pyridine with Silver Nanoparticles on Poly(ethylene terephthalate) Film for Anti‐Microbial Properties
Authors: Jiang Juan , Winther‐Jensen Bjørn , Kjær Erik M.
Published: June 2006

4‐vinyl pyridine was polymerized on poly(ethylene terephthalate) (PET) film by using lower energy pulsed AC plasma under low pressure in Ar atmosphere. The plasma polymerized coating was characterized by ATR Fourier transform infrared (FT‐IR), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE‐SEM), atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS). Different thicknesses of poly(4‐vinyl pyridine) coating under different plasma polymerization conditions were studied. Silver nanoparticles with diameter around 50nm deposit were precipitated on the poly(4‐vinyl pyridine) coating by UV irradiation in Silver nitride water solution, in order to enhance the anti‐microbial properties. Different kinds of modified PET films were tested for anti‐microbial properties against yeast (Debaryomyces hansenii) by using microbiological analyser µ‐4200 and direct microscopic count method.
Surface Structure and Stereocomplex Formation of Enantiomeric Polylactide Blends Using Poly(dimethyl siloxane) as a Probe Polymer
Authors: Lee Jin‐Kook , Kim Mi‐Ra , Lee Hyun‐Jeong , Chung Ildoo , Lim Kwon Taek , Jeon Sangik , Lee Won‐Ki
Published: June 2006

In the stereocomplex between enantiomeric poly(l‐lactide) (l‐PLA) and poly(d‐lactide), crystallites formed as a result of stereocomplexation, equimolar l‐ and d‐lactide unit sequences are packed side by side. The stereocomplex exhibits a melting temperature higher by about 50 °C than that of each homopolymer. In this study, we attempt to obtain further insight into the stereocomplex‐induced surface structure of enantiomeric PLA blend films. The design of the blend systems is based on principles of surface segregation of multicomponent polymeric systems with a low surface energy, triblock copolymer (l‐PLA‐b‐PDMS‐b‐l‐PLA) of l‐PLA and poly‐(dimethyl siloxane). (l‐PLA‐b‐PDMS‐b‐l‐PLA/l‐PLA) blend films showed the surface segregation of PDMS, regardless of blend composition while the surface composition of PDMS in the (l‐PLA‐b‐PDMS‐b‐l‐PLA/d‐PLA) blend films was strongly depended on blend composition or a degree of complexation. These results are likely due to strong interaction between d‐ and l‐lactide unit sequences, which prevents the surface segregation of PDMS.
Acetazolamide acts directly on the human skeletal muscle chloride channel
Authors: Eguchi Hiroto , Tsujino Akira , Kaibara Muneshige , Hayashi Hideki , Shirabe Susumu , Taniyama Kohtaro , Eguchi Katsumi
Published: June 2006

Acetazolamide, a carbonic anhydrase inhibitor, is used empirically in neuromuscular diseases with episodic ataxia, weakness, and myotonia, although not all of the mechanisms responsible for its therapeutic effects are understood. To elucidate whether acetazolamide acts directly on the human skeletal muscle voltage‐gated chloride channel (ClC‐1), which is associated with myotonia, we evaluated the effects of acetazolamide on ClC‐1 expressed in cultured mammalian cells, using whole‐cell recording. Acetazolamide significantly shifted the voltage dependency of the open probability (Po) toward negative potentials in a dose‐dependent manner, resulting in an increase of chloride conductance at voltages near the resting membrane potential. This effect was attenuated when using a pipette solution containing 30 mmol/L Hepes. These results suggest that acetazolamide can influence the voltage‐dependent opening gate of ClC‐1 through a mechanism related to intracellular acidification by inhibiting carbonic anhydrase, and that the therapeutic effects of acetazolamide in neuromuscular diseases may be mediated by activation of ClC‐1. Muscle Nerve, 2006
Passive mechanical properties of maturing extensor digitorum longus are not affected by lack of dystrophin
Authors: Wolff Andrew V. , Niday Ashley K. , Voelker Kevin A. , Call Jarrod A. , Evans Nicholas P. , Granata Kevin P. , Grange Robert W.
Published: June 2006

Mechanical weakness of skeletal muscle is thought to contribute to onset and early progression of Duchenne muscular dystrophy, but this has not been systematically assessed. The purpose of this study was to determine in mice: (1) whether the passive mechanical properties of maturing dystrophic (mdx) muscles were different from control; and (2) if different, the time during maturation when these properties change. Prior to and following the overt onset of the dystrophic process (14–35 days), control and dystrophic extensor digitorum longus (EDL) muscles were subjected to two passive stretch protocols in vitro (5% strain at instantaneous and 1.5 L0/s strain rates). Force profiles were fit to a viscoelastic muscle model to determine stiffness and damping. The mdx and control EDL muscles exhibited similar passive mechanical properties at each age, suggesting a functional threshold for dystrophic muscle below which damage may be minimized. Determining this threshold may have important clinical implications for treatments of muscular dystrophy involving physical activity. Muscle Nerve, 2006
Long‐term administration of pirfenidone improves cardiac function inmdxmice
Authors: Van Erp Christel , Irwin Nicole G. , Hoey Andrew J.
Published: June 2006

Duchenne muscular dystrophy, an X‐linked recessive neuromuscular disorder due to lack of the protein dystrophin, manifests as progressive muscle degeneration and cardiomyopathy with increased fibrosis. The exact mechanisms involved in fibrosis are unknown, but a cytokine, transforming growth factor‐beta (TGF‐β), is a likely mediator. This study tested whether the TGF‐β antagonist, pirfenidone, could reduce cardiac fibrosis. Eight‐month‐oldmdxmice were treated for 7 months with 0.4%, 0.8%, and 1.2% pirfenidone in drinking water; untreated water was given to controlmdxand C57 mice. Mice treated with 0.8% and 1.2% pirfendone had lowered cardiac TGF‐β mRNA and improved in vitro cardiac contractility (P< 0.05) to levels consistent with C57 mice, yet without a change in cardiac stiffness or fibrosis. These results show that the TGF‐β antagonist, pirfenidone, can improve cardiac function inmdxmice, potentially providing a new avenue for developing cardiac therapies for patients with Duchenne muscular dystrophy. Muscle Nerve, 2006
Isaacs' syndrome: Clinical and electrophysiological response to gabapentin
Authors: Dhand Upinder K.
Published: June 2006

A patient with Isaacs' syndrome had generalized muscle spasms, twitching, and progressive muscle stiffness for 21 years. Electrodiagnostic study showed continuous spontaneous motor‐unit activity and the presence of M‐wave afterdischarges. He responded dramatically to treatment with carbamazepine but developed a drug rash; his treatment was changed to gabapentin with continued improvement. Subsequent nerve conduction studies showed decreased amplitude and later an absence of M‐wave afterdischarges. Gabapentin thus appears to be an effective treatment for Isaacs' syndrome. Muscle Nerve, 2006
Influences of ventilation on maximal isometric force of the finger flexors
Authors: Li Sheng , Laskin James J.
Published: June 2006

Force production may be influenced by the phase of ventilation during which force is exerted. To examine the potential influences of ventilation on variability in maximal force measurements, we recorded peak isometric forces of the finger flexors during normal breathing, forced inspiration, forced expiration, and the Valsalva maneuver in 14 healthy adult subjects. The peak force increased significantly from forced inspiration to forced expiration (about 10%). Both forced expiration and inspiration resulted in increases in the flexor/extensor cocontraction ratio, whereas the Valsalva maneuver had no significant effects on maximal force or cocontraction ratio. Thus, this study clearly demonstrates the effects of ventilation on maximal finger force‐generating capability. Ventilation needs to be controlled for accurate assessments of maximal force. Muscle Nerve, 2006
Size and shape evolution of pores in a viscoplastic matrix under compression
Authors: Berli M. , Accorsi M. L. , Or D.
Published: June 2006

The frequent use of soils and earth materials for hydraulic capping and for geo‐environmental waste containment motivated our interest in detailed modelling of changes in size and shape of macro‐pores to establish links between soil mechanical behaviour and concurrent changes in hydraulic and transport properties. The objective of this study was to use finite element analysis (FEA) to test and extend previous analytical solutions proposed by the authors describing deformation of a single macro‐pore embedded in linear viscoplastic soil material subjected to anisotropic remote stress. The FEA enables to consider more complex pore geometries and provides a detailed picture of matrix yield behaviour to explain shortcomings of approximate analytical solutions. Finite element and analytical calculations agreed very well for linear viscous as well as for viscoplastic materials, only limited for the case of isotropic remote stress due to the simplifications of the analytical model related to patterns and onset of matrix‐yielding behaviour. FEA calculations were compared with experimental data obtained from a compaction experiment in which pore deformation within a uniform modelling clay sample was monitored using CAT scanning. FEA predictions based on independently measured material properties and initial pore geometry provided an excellent match with experimentally determined evolution of pore size and shape hence lending credence to the potential use of FEA for more complex pore geometries and eventually connect macro‐pore deformation with hydraulic properties. Copyright © 2006 John Wiley & Sons, Ltd.
Protecting TCP from a misbehaving receiver
Authors: Cheng Rung‐Shiang , Lin Hui‐Tang
Published: June 2006

This study presents the design and implementation of a robust TCP congestion control algorithm. TCP was originally designed for cooperative environments, and its evolution over the years has been built on the same basis. TCP expects the end hosts to cooperate with the TCP senders in implementing end‐to‐end congestion control. Therefore, misbehavior of a TCP receiver may result in an unfair division of the available bandwidth between the conforming flows and the irresponsible flows. Accordingly, this study examines the issues arising when conforming TCP connections are obliged to coexist with misbehaving connections. A modification to the TCP protocol is proposed to deal with various types of TCP misbehavior. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of conjugated linoleic acid grafting on the hemocompatibility of polyacrylonitrile membrane
Authors: Kung Fu‐Chen , Yang Ming‐Chien
Published: June 2006

Polyacrylonitrile (PAN) membrane was hydrolyzed with NaOH(aq) and grafted with conjugated linoleic acid (CLA) via esterification with 1,3‐propanediol. The resulting CLA grafted PAN membranes were characterized using Fourier transform infrared spectrometry (FT‐IR) and X‐ray photoelectronic spectroscopy (XPS). The effects of CLA grafting on the blood coagulation, platelet aggregation, and oxidative stress were evaluated using human blood. The complete blood count (CBC) and coagulation time (CT) was evaluated in vitro for hemocompatibility. After CLA grafting, the proliferation of human umbilical vein endothelial cells (HUVECs) on the membranes were improved. In addition, the production of reactive oxygen species (ROS) was measured by the chemiluminescence (CL) method to evaluate the oxidative stress. The results showed that the CLA‐grafted PAN membrane could keep the CBC values more stable than unmodified PAN membrane. The CLA‐grafted PAN membranes also showed longer CT. CLA‐grafted PAN membrane could keep the CL counts of hydrogen peroxide and superoxide values more stable than unmodified PAN membrane. These results suggest that a CLA‐grafted PAN membrane could offer protection for patients against oxidative stress and would be helpful for reducing the dosage of anticoagulant during hemodialysis. Copyright © 2006 John Wiley & Sons, Ltd.
Proteomic analysis of estrogen response of premalignant human breast cells using a 2‐D liquid separation/mass mapping technique
Authors: Zhao Jia , Zhu Kan , Lubman David M. , Miller Fred R. , Shekhar Malthy P. V. , Gerard Brigitte , Barder Timothy J.
Published: June 2006

A 2‐D liquid‐phase separation method based on chromatofocusing and nonporous silica RP‐HPLC followed by ESI‐TOF‐MS was used to analyze proteins in whole cell lysates from estrogen‐treated and untreated premalignant, estrogen‐responsive cell line MCF10AT1 cells. 2‐D mass maps in the pH range 4.6–6.0 were generated with good correlation to theoretical Mr values for intact proteins. Proteins were identified based on intact Mr, pI and PMF, or MS/MS sequencing. About 300 unique proteins were identified and 120 proteins in mass range 5–75 kDa were quantified upon treatment of estrogen. Around 40 proteins were found to be more highly expressed (>four‐fold) and 17 were down‐regulated (>four‐fold) in treated cells. In our study, we found that many altered proteins have characteristics consistent with the development of a malignant phenotype. Some of them have a role in the ras pathway or play an important role in signal pathways. These changed proteins might be essential in the estrogen regulation mechanism. Our study highlights the use of the MCF10AT1 cell line to examine estrogen‐induced changes in premalignant breast cells and the ability of the 2‐D mass mapping technique to quantitatively study protein expression changes on a proteomic scale.
Proteomic analysis of autoantibodies in patients with hepatocellular carcinoma
Authors: Takashima Motonari , Kuramitsu Yasuhiro , Yokoyama Yuichiro , Iizuka Norio , Harada Toshio , Fujimoto Masanori , Sakaida Isao , Okita Kiwamu , Oka Masaaki , Nakamura Kazuyuki
Published: June 2006

To detect autoantibodies that could be diagnostic markers for hepatocellular carcinoma (HCC), we analyzed serum autoantibodies comprehensively that showed immunoreactivity to proteins in tumor tissue obtained from patients with HCC. Fifteen paired samples of HCC tissue and corresponding nontumorous liver tissue as well as five normal liver tissue samples were used in the study. A combination of proteomics and SEREX (serologic analysis of recombinant cDNA expression libraries) technique was used. Tissue proteins were separated by 2‐DE, transferred onto PVDF membranes, and immunoblotted with autologous sera. By comparing each immunoblot pattern, we identified four immunoreactive spots with stronger staining intensity in tumorous tissues than in corresponding nontumorous tissues and in normal liver tissues. Matched proteins on 2‐DE gels were identified by LC‐MS/MS. These immunoreactive proteins were heat shock 70 kDa protein 1 (HSP70), glyceraldehyde 3‐phosphate dehydrogenase, peroxiredoxin, and manganese superoxide dismutase (Mn‐SOD). In HCC sera, occurrences of autoantibodies against these proteins were 7/15 (46.7%), 5/15 (33.3%), 5/15 (33.3%), and 6/15 (40.0%), respectively, whereas 2/20 (10.0%), 7/20 (35.0%), 0/20 (0.0%), and 2/20 (10.0%) were in control sera. Immunoblot analysis using commercially available purified proteins was performed to confirm the specificity of autoantibodies. By statistical analysis, autoantibodies against HSP70, peroxiredoxin, and Mn‐SOD showed significantly high‐frequency immunoreaction in HCC sera. The three antibodies were considered patient‐specific antibodies in HCC and may be candidate diagnostic biomarkers for HCC.
Construction of quantitative proteome reference maps of mouse spleen and lymph node based on two‐dimensional gel electrophoresis
Authors: Kimura Yayoi , Yokoyama Ryo , Ishizu Yuri , Nishigaki Toshio , Murahashi Yasuaki , Hijikata Atsushi , Kitamura Hiroshi , Ohara Osamu
Published: June 2006

Quantitative features of the proteome are extremely useful for studying cellular processes at a molecular level. In this study, we attempted to construct quantitative reference proteome maps of the mouse spleen and lymph node based on 2‐DE followed by protein identification using MS. We analyzed more than 1000 spots on the 2‐DE images and consequently were able to determine that 919 spots were derived from 328 different genes. To obtain statistically reliable information of the protein levels from these 2‐DE images, we measured the volumes of the respective spots on 2‐DE images obtained by four to six independent experimental runs. These measurements were used to calculate the variability of the volumes of the respective spots on 2‐DE following subcellular fractionation, which enabled us to discriminate differentially produced proteins from those within the range of intrinsic variability. More importantly, while the 2‐DE data have been traditionally collected in a gel image‐based manner, the resultant quantitative 2‐DE data could be analyzed using the same procedure as that for mRNA expression profiles. This greatly assists in bridging the gap between the analyses of transcriptomes and proteomes and enables the integration of this data on the same informational platform.
Proteomic analysis of inflammatory biomarkers in bronchoalveolar lavage
Authors: de Torre Carlos , Ying Sai‐Xia , Munson Peter J. , Meduri G. Umberto , Suffredini Anthony F.
Published: June 2006

To assess markers of lung inflammation, we used SELDI‐TOF and 2‐DE to study changes in bronchoalveolar lavage (BAL) protein in 33 subjects challenged with local bronchial lung endotoxin and saline and in 11 patients with acute respiratory distress syndrome (ARDS). Differences in the SELDI‐TOF spectra were assessed by t‐test after baseline subtraction, normalization to total ion current and alignment by m/z calibration. The temporal changes in acute inflammatory BAL (6, 24 and 48 h following endotoxin challenge) on hydrophobic binding chip surfaces revealed the differential presence of proteins of 9, 14, 18 and 28 kDa (all p <0.001) in the inflammatory BAL. This differential pattern was also found in the ARDS BAL. Principal component analysis of the entire SELDI‐TOF spectra separated normal BAL, experimental and clinical lung inflammation supporting the notion of a distinctive protein pattern associated with acute lung inflammation. An analysis of the hydrophobic fraction of the inflammatory BAL using 2‐DE, identified increased levels of apolipoprotein A1, and S100 calcium‐binding proteins A8 and A9 in the inflammatory BAL. This pattern was also found in ARDS BAL after immunoblot analysis. These approaches will be useful to improve current methods of monitoring lung inflammation and to identify new therapeutic targets.
Prostatic tissue protein alterations due to delayed time to freezing
Authors: Jackson David , Rowlinson Rachel A. , Eaton Cassie K. , Nickson Janice A. , Wilson Ian D. , Mills Jonathan D. , Wilkinson Robert W. , Tonge Robert P.
Published: June 2006

Clinical studies often produce fresh tissue samples, which ideally should be immediately snap frozen for storage and subsequent analysis. However, this is often not practically possible, and there is inevitably a time period during which the sample is stored on ice. The delay in freezing may allow endogenous degradation of proteins to occur, affecting 2‐D gel protein profiles. This study aims to investigate the type and extent of this degradation by examining how the time‐to‐freezing delay alters prostatic tissue protein profile. The prostate carcinoma‐3 cell line (PC‐3), prostate cancer xenografts and canine prostate were used with fluorescence 2‐D DIGE to assess protein degradation. It was found that 30‐min processing time had minimal effects on the protein profile. Longer delays had little visible effect, but subtle alterations in protein profile began to accumulate as time increased. These data support the practice of completing tissue processing as rapidly as possible, and indicate that short processing times do not notably perturb the 2‐D gel spot pattern from prostatic tissue.
Proteomic analysis of the acid‐soluble organic matrix of the chicken calcified eggshell layer
Authors: Mann Karlheinz , Maček Boris , Olsen Jesper V.
Published: June 2006

The major difference between inorganic minerals and biominerals is the presence of an organic matrix consisting of proteins, glycoproteins, proteoglycans, and polysaccharides, which is synthesized by specialized cells under genetic control before or during mineralization. The organic matrix is thought to play a major role in the assembly of the biomineral and determination of its mechanical properties. The recent elucidation of the chicken genome provided an opportunity to explore the matrix proteome of a biomineral using up‐to‐date MS‐based technology. We identified 520 proteins in this matrix including the ten matrix proteins already known before. The identified proteins were divided into three abundance groups using the exponentially modified protein abundance index described recently which was roughly calibrated with the few known data on protein yield derived from Edman sequence analysis. A small group of 32 highly abundant proteins contained the presently known eggshell‐specific proteins and all of the other known eggshell matrix constituents identified before with much less sensitive conventional methods. The present study, which is the first comprehensive proteomic study of a vertebrate biomineral, is intended as a starting point for the detailed molecular characterization of eggshell matrix proteins, their interactions in the matrix network and functional studies.
Synthesis and characterization of a novel electroluminescent polymer based on a phenoxazine derivative
Authors: Ito Yuichi , Shimada Takahiro , Ha Jaekook , Vacha Martin , Sato Hisaya
Published: June 2006

We report the preparation of a new electroluminescent polymer by the oxidative coupling copolymerization of N‐(4‐n‐butylphenyl)phenoxazine and 9,9‐di‐n‐butylfluorene with ferric(III) chloride. The reaction yields soluble polymers with a weight‐average molecular weight as high as 9000. The reactivity has been studied with respect to the reaction time, temperature, and feed ratio of the comonomers. Under optimum conditions, a copolymer with a 50% comonomer incorporation ratio can be obtained in a 75% yield. The polymers have been characterized with differential scanning calorimetry, cyclic voltammetry, and optical spectroscopy. A simple single‐layer light‐emitting‐diode device of an indium tin oxide/polymer/Mg–Ag structure shows a luminance of 200 cd/m2 at an 18‐V operating voltage. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4338–4345, 2006
Molecular dynamics simulations of the hydrophobin SC3 at a hydrophobic/hydrophilic interface
Authors: Fan Hao , Wang Xiaoqin , Zhu Jiang , Robillard George T. , Mark Alan E.
Published: June 2006

Hydrophobins are small (∼100 aa) proteins that have an important role in the growth and development of mycelial fungi. They are surface active and, after secretion by the fungi, self‐assemble into amphipathic membranes at hydrophobic/hydrophilic interfaces, reversing the hydrophobicity of the surface. In this study, molecular dynamics simulation techniques have been used to model the process by which a specific class I hydrophobin, SC3, binds to a range of hydrophobic/hydrophilic interfaces. The structure of SC3 used in this investigation was modeled based on the crystal structure of the class II hydrophobin HFBII using the assumption that the disulfide pairings of the eight conserved cysteine residues are maintained. The proposed model for SC3 in aqueous solution is compact and globular containing primarily β‐strand and coil structures. The behavior of this model of SC3 was investigated at an air/water, an oil/water, and a hydrophobic solid/water interface. It was found that SC3 preferentially binds to the interfaces via the loop region between the third and fourth cysteine residues and that binding is associated with an increase in α‐helix formation in qualitative agreement with experiment. Based on a combination of the available experiment data and the current simulation studies, we propose a possible model for SC3 self‐assembly on a hydrophobic solid/water interface. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Substitution of Nd at Ba site in Gd123
Authors: Mirzadeh M. , Akhavan M.
Published: June 2006

Structural and superconducting behaviors of Gd(Ba2−x Ndx)Cu3O7+δ with 0.0 ≤ x ≤ 0.8 have been studied by X‐ray diffraction and electrical and magnetic measurements. The XRD patterns show the samples with x ≤ 0.5 are isostructure 123 phase, and an orthorhombic–tetragonal phase transition occurs at x = 0.2. The transition temperature decreases linearly with increasing Nd content. This behavior is also observed in the curves of the room‐temperature resistivity versus Nd doping. The metal–insulator and superconductor–insulator transitions occur at x cMIT = 0.3 and x cSIT = 0.35, respectively. The conduction mechanisms of the normal‐state resistivity are the Coulomb gap (CG) for x < x cMIT, two‐dimensional variable‐range hopping (2D‐VRH) at x cMIT ≤ x ≤ x cSIT, and 3D‐VRH for x > x cSIT. The pinning energy derived from the thermally activated flux creep model, and coupling energy derived from the Ambegaokar–Halperin theory decrease with increasing applied magnetic field as a power‐law relation, and decrease as Nd content increases. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultrasonic study of Jahn–Teller effect in charge‐ordered Nd1−xCax MnO3 (x = 0.4–0.8) manganites
Authors: Liu Yi , Kong Hui , Su Jinrui , Zhu Changfei
Published: June 2006

The ultrasonic, magnetic and transport properties of charge‐ordered manganites Nd1−x Cax MnO3 (x = 0.4, 0.5, 0.6, 0.7 and 0.8) were studied between 15 and 300 K. Resistivity and magnetization measurements show that all the samples undergo a charge‐ordering transition at low temperature. Upon cooling from 300 K, an obvious softening of sound velocity above the charge‐ordering transition temperature (T CO) and dramatic stiffening below T CO were observed for all samples. This feature gives clear evidence for strong electron–phonon coupling in these compounds. The Jahn–Teller coupling energy E JT increases with increasing Ca concentration x, and reaches the maximum at around x = 0.6, which is similar in characteristics to the T CO. The results imply that the charge‐ordering in Nd1−x Cax MnO3 is dominated by the Jahn–Teller effect. Our analyses suggested that the type of cooperative Jahn–Teller distortion be Q 2‐mode for x ≤ 0.6, and change to Q 3 mode at around x = 0.6 in the CO state. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling non‐exponential polarization relaxations in interacting dipole systems
Authors: Kühn M. , Kliem H.
Published: June 2006

Relaxational polarization processes of many polar dielectrics can be described in the time domain by stretched exponential functions which is referred to as Kohlrausch behaviour. For an interacting system of statistically distributed permanent dipoles arranged between two coplanar electrodes numerical calculations of the transient polarization curves are performed showing these long lasting relaxations. The electrostatic dipole–dipole interaction is considered and the electrodes are taken into account using the method of image dipoles. The dipoles are fluctuating thermally activated in double well potentials according to the Boltzmann statistics. The computation is based on deterministic local field calculations and on weighted probabilistic dynamic Monte Carlo steps. In this paper we focus on the small signal response after applying a step function of the electric field. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐plane anisotropy in uniaxially‐strained GaN films detected by optical diffraction technique
Authors: Adachi Satoru , Toda Yasunori , Ishiguro Tetsuro , Hoshino Katsuyuki , Arakawa Yasuhiko
Published: June 2006

The cover picture of this issue of physica status solidi (c) has been taken from the article [1].