bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of symptomatic diabetic patients with normal nerve conduction studies: Utility of cutaneous silent periods and autonomic tests
Authors: Koytak Pinar Kahraman , Isak Baris , Borucu Deniz , Uluc Kayihan , Tanridag Tulin , Us Onder 
Published: February 2011

AbstractEstablished electrophysiological methods have limited clinical utility in the diagnosis of small‐fiber neuropathy (SFN). In this study, diabetic patients with clinically diagnosed SFN were evaluated with autonomic tests and cutaneous silent periods (CSPs). Thirty‐one diabetic patients with clinically suspected SFN and normal nerve conduction studies were compared with 30 controls. In the upper extremities (UE), the CSP parameters did not differ statistically between the patient and control groups, whereas, in the lower extremities (LE), patients had prolonged CSP latencies (P = 0.018) and shortened CSP durations (P < 0.001). The sensitivity of the CSP duration was 32.6%, and the specificity was 96.7%. The expiration‐to‐inspiration ratios and amplitudes of the sympathetic skin responses in the lower extremities were also reduced. Our findings indicate that the diagnostic utility of CSPs was higher than that of the autonomic tests to support the clinically suspected diagnosis of SFN. Muscle Nerve, 2011
Subacute myopathy in a mature patient due to multiple acyl‐coenzyme a dehydrogenase deficiency
Authors: Kaminsky Pierre , Acquaviva‐Bourdain Cecile , Jonas Jacques , Pruna Lelia , Chaloub Gihan e , Rigal Odile , Grignon Yves , Vianey‐Saban Christine 
Published: February 2011

AbstractIntroduction: Multiple acyl‐coenzyme A dehydrogenase deficiency (MADD), also called glutaric aciduria type II, is an inherited metabolic disorder resulting from a deficiency in electron transfer flavoprotein (ETF) or of its ubiquinone oxidoreductase (ETF‐QO). It usually occurs in the neonatal period or in early infancy and, very rarely, in adolescents and young adult patients. Methods: We report the case of a 55‐year‐old woman who developed a painful subacute myopathy. Results: Lipid accumulation was found at biopsy. MADD was confirmed by plasma acylcarnitine profile and by assessment of ETF‐QO activity in muscle. Conclusions: This study demonstrates that metabolic myopathies usually found in infancy may be also diagnosed in older patients. MADD may be easily treated by riboflavin and coenzyme Q10 and therefore should be included in the differential diagnosis of adult‐onset painful myopathy. Muscle Nerve 43: 444–446, 2011
Electromechanical delay in biceps brachii assessed by ultrafast ultrasonography
Authors: Hug François , Gallot Thomas , Catheline Stefan , Nordez Antoine 
Published: February 2011

AbstractUsing ultrasound we tested the utility of determining the relative contribution of the main muscle structures/mechanisms to the electromechanical delay in the biceps brachii. Nine subjects underwent electrically evoked contractions with the echographic probe maintained over the muscle and the myotendinous junction. No difference was found between the onset of muscle fascicle motion (Dm, 5.57 ± 1.37 ms) and the onset of myotendinous junction motion (Dt, 5.47 ± 1.38 ms), whereas significant differences were found between Dm/Dt and electromechanical delay (approximately 10 ms). Electromechanical delay can be used as a model for studying the effects of neuromuscular disorders or various constraints that affect excitation–contraction coupling and/or muscle force transmission. Muscle Nerve, 2011
Getting a job is only half the battle: Maternal job loss and child classroom behavior in low‐income families
Authors: Hill Heather D. , Morris Pamela A. , Castells Nina , Walker Jessica Thornton 
Published: February 2011

AbstractThis study uses data from an experimental employment program and instrumental variables (IV) estimation to examine the effects of maternal job loss on child classroom behavior. Random assignment to the treatment at one of three program sites is an exogenous predictor of employment patterns. Cross‐site variation in treatment‐control differences is used to identify the effects of employment levels and transitions. Under certain assumptions, this method controls for unobserved correlates of job loss and child well‐being, as well as measurement error and simultaneity. IV estimates suggest that maternal job loss sharply increases problem behavior but has neutral effects on positive social behavior. Current employment programs concentrate primarily on job entry, but these findings point to the importance of promoting job stability for workers and their children. © 2011 by the Association for Public Policy Analysis and Management.
Kinetic study of polysulfide‐acrylate click reaction by DEA and DMA
Authors: Zhou Baijie , Shen Mingxia , Wang Qingjun , Chen Qingmin 
Published: February 2011

AbstractThe curing process of a polysulfide (PSF) with a triacrylate crosslinker in the presence of an amine catalyst at room temperature is a rapid Michael addition. This reaction was monitored by real‐time infrared spectrum (RTIR). The results of the RTIR show that the consumptions of thiol and acrylate are stoichiometric until 80% conversion, indicating the characteristics of a “click” reaction. Dielectric analyzer (DEA) and dynamic mechanical analyzer (DMA) were employed to investigate the curing kinetics from which the activation energies of this curing reaction were obtained and shown to correlate with each other. In addition, the influences of the types and amount of amine catalyst, the different molecular weights of PSFs, and the triacrylate crosslinkers were discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Fabrication of highly porous starch monoliths and their application as green desiccants
Authors: Mi Xue , Wang Wenchao , Gao Jianping , Long Ying , Xing Fubao , Wang Xiaodong , Xu Fangqiang , You Xiudong , Li Shufeng , Liu Yu 
Published: February 2011

AbstractStarch monoliths with oriented porous structures were developed from starches and glycerin as a plasticizer using unidirectional freeze‐drying technology. The morphology of the porous starch monoliths made from different starches was determined by scanning electron microscopy (SEM), and the porosity, mechanical properties and moisture absorption of the porous materials were evaluated. The results show that porous starch monoliths made from oxidized starch with 15% glycerin had good mechanical strength with the best moisture absorption. Increasing the starch concentration significantly improved their strength and increased the moisture absorption rate as well. The moisture absorption of the porous monolith made from oxidized starch is comparable with commonly used desiccants. The porous starch monoliths can successfully remove water from 95% ethanol to produce absolute ethanol due to their selective absorption for water. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation and modeling of the mechanical properties of graphite nanoplatelets based rubber nanocomposites for pressure sensing applications
Authors: Mahmoud Waleed E. , Al‐Ghamdi A. A. , Al‐Solamy Falleh R. 
Published: February 2011

AbstractAcrylonitrile butadiene rubber (NBR) compounds filled with different concentrations of graphite nanoplatelets were experimentally investigated. The stress–strain curves of the nanocomposites were studied, which suggest good filler–matrix adhesion. The large reinforcement effect of the filler followed the Guth model for non‐spherical particles. The effect of graphite nanoplatelets on the cyclic fatigue and hysteresis was also examined. The loading and unloading stress–strain relationships for any cycle were described by applying Ogden's model for rubber nanocomposites. With this model for incompressible materials, expressions may be developed to predict the stress–strain relationship for any given cycle. The dissipated energy increased with graphite nanoplatelets concentrations and decrease with number of cycles. The rate of damage accumulation becomes marginal after first ten cycles. The rate of damage increases as the amount of graphite nanoplatelets increase into the rubber matrix. Copyright © 2011 John Wiley & Sons, Ltd.
Electropolymerization of layer‐by‐layer precursor polymer films
Authors: Waenkaew Paralee , Phanichphant Sukon , Advincula Rigoberto C. 
Published: February 2011

AbstractThe layer‐by‐layer (LbL) self‐assembly has been used to fabricate polymer thin films on any solid substrates. The multilayer polymer thin films are constructed by alternating adsorption of anionic and cationic polymers. Polyelectrolyte multilayer ultrathin films containing anionic poly[2‐(thiophen‐3‐yl)ethyl methacrylate‐co‐methacrylic acid]; P(TEM‐co‐MA) and cationic poly[4‐(9H‐carbazol‐9‐yl)‐N‐butyl‐4‐vinyl pyridium bromide]; P4VPCBZ, were fabricated. The growth of multilayer ultrathin films was followed by UV–Vis absorption spectrophotometer and surface plasmon resonance spectroscopy (SPR). The deposition of P(TEM‐co‐MA)/P4VPCBZ as multilayer self‐assembled ultrathin films regularly grow which showed linear growth of absorbance and thickness with increasing the number of layer pair. Cross‐linking of the layers was verified by cyclic voltammetry (CV), UV–Vis spectrophotometry and electrochemical surface plasmon resonance (EC‐SPR) spectroscopy with good electro‐copolymerizability. This was verified by spectroelectrochemistry. The SPR angular‐reflectivity measurement resulted in shifts to a higher reflectivity according to the change in the dielectric constant of the electropolymerized film. Copyright © 2011 John Wiley & Sons, Ltd.
Carbon nanocones/discs – a new type of filler to improve the thermal and mechanical properties of polymer films
Authors: Gofman Iosif V. , Abalov Ivan V. , Gladchenko Svetlana V. , Afanas'eva Nadezhda V. 
Published: February 2011

AbstractThe mechanical characteristics and thermal properties of composite films based on the thermally stable aromatic polyimide (PI) (PMDA‐ODA) and carbon nanocones/discs (CNC) were studied. The introduction of CNC to PMDA‐ODA leads to the substantial increase of film stiffness. The Young's modulus values of the composite films are somewhat higher than those of the previously characterized composite films of this PI filled with nanoclay, carbon nanofibers, and asbestos‐like hydrosilicate nanotubes. The introduction of CNC into PMDA‐ODA (concentrations of CNC were up to 15 vol%) does not cause any marked aggregation of nanoparticles. The presence of CNC in the PI matrix does not affect the glass transition temperature of the polymer but hinders chain mobility at temperatures above Tg. This behavior makes it possible to increase the working temperature range of the composite films containing more than 5 vol% of CNCs, up to the temperature of thermal decomposition. The introduction of CNC into PMDA‐ODA leads to dramatic (∼12 orders of magnitude) increase of active electrical conductivity of the material. Copyright © 2011 John Wiley & Sons, Ltd.
Structure and properties of chlorinated polyvinyl chloride graft copolymer with higher property
Authors: Xu Chao , Wang Shuangshuang , Shao Lu , Zhao Jiruo , Feng Ying 
Published: February 2011

AbstractIn this work, maleic anhydride (MAH) was grafted onto chlorinated polyvinyl chloride (CPVC) with high chlorine content (66 wt%) via in‐situ chlorinating graft copolymerization (ISCGC) to obtain the material with improved mechanical strength, softening point, and thermal stability of the material. The structure of the graft product (CPVC‐cg‐MAH) was characterized by FTIR, 1H NMR, GPC, and UV. CPVC‐cg‐MAH contains less vinylidene chloride (CCl2) units and double bond than corresponding CPVC. Meanwhile, the number–average molecular weight (Mn) and weight–average molecular weight (Mw) of CPVC‐cg‐MAH are increased, but distribution of molecular weight (Mw/Mn) is decreased. Then, the tensile strength and notched impact strength of CPVC‐cg‐MAH increased by 14.5 and 34.6%, respectively. Furthermore, the results of DMA, DSC, TG, and Vicat softening point showed that the loss peak of CPVC‐cg‐MAH was higher evidently than CPVC and moved to high temperature, the glass transition temperature (Tg) of CPVC‐cg‐MAH was consistent with CPVC, initial weight loss temperature, and maximum weight loss rate temperature of CPVC‐cg‐MAH increased by 7.2°C and 6.1°C, respectively, and the Vicat softening temperature of CPVC‐cg‐MAH increased by 15°C and up to 130°C. Copyright © 2011 John Wiley & Sons, Ltd.
Characterization of keratin–collagen 3D scaffold for biomedical applications
Authors: Balaji S. , Kumar Ramadhar , Sripriya R. , Rao Urmila , Mandal Abhishek , Kakkar Prachi , Reddy P. NeelaKanta , Sehgal Praveen Kumar 
Published: February 2011

AbstractFabrication of keratin–collagen (KC) 3D scaffold with improved thermal denaturation rate is reported. In vitro application of (KC) scaffold stimulates basic extra cellular matrix constituents. KC Scaffold considerably reduced undesirable properties of both collagen and keratin while collagen incorporation reduces the fragility with increases of strength and flexibility in the scaffold. In addition to this, the scaffold showed homogenous well‐interconnected pores in the range of 10–100 µm when observed in scanning electron microscope. Usage of keratin in KC scaffold offers increased biodegradation rate and higher denaturation rate in addition to its rapid cell growth with normal morphology ultimately reaching cell population of 3.9–9.7 million per cm3 after 48 hr in KC scaffold. Circular dichroism (CD) and Fourier transform spectroscopy (FT‐IR) of KC showed presence of helical structure of collagen and ß‐turns of keratin confirming retention of native structures of both the proteins KC scaffold showed good swelling behavior and water uptake. Our study strongly supports the superidity of KC scaffold over the collagen or keratin when they are independently used for tissue engineering applications. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation and characterization of CNTs/PE micro‐nanofibers
Authors: Wang Hailian , Xiao Ru 
Published: February 2011

AbstractMultiwalled carbon nanotubes (CNTs)/polyethylene micro‐nanofibers with content ranging from 0.5 to 10 wt% of CNTs were prepared for the first time by melt extrusion of immiscible blends with cellulose acetate butyrate (CAB) and subsequent removal of CAB matrix. The morphology development of dispersed phase was studied with samples collected at different zones in a twin‐screw extruder. The morphology of the CNTs in PE was found to be in forms of both individual and agglomerations. The average diameters of CNTs/PE nanofibers increased with increasing the CNTs content. The electrical conductivity of CNTs/PE nanofibers was studied and a percolation threshold of about 4 wt% was obtained. In addition, the crystalline structures of the CNTs/PE nanofibers were analyzed, indicating a decrease in the crystallinity with the addition of CNTs. The thermal properties of composite fibrils were also modified. This paper demonstrates a good approach for the preparation of CNTs/TP nanofibers by in situ microfibrillar formation. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and gas permeation properties of poly(vinyl chloride)‐graft‐poly(vinyl pyrrolidone) membranes
Authors: Yeon Seung Hyeon , Ahn Sung Hoon , Kim Jong Hak , Lee Ki Bong , Jeong Yujin , Hong Seong Uk 
Published: February 2011

AbstractA series of amphiphilic graft copolymers consisting of poly(vinyl chloride) (PVC) main chains and poly(vinyl pyrrolidone) (PVP) side chains, i.e. PVC‐g‐PVP, was synthesized via atom transfer radical polymerization (ATRP), as confirmed by 1H NMR, FT‐IR spectroscopy, and gel permeation chromatography (GPC). Transmission electron microscope (TEM) and small angle X‐ray scattering (SAXS) analysis revealed the microphase‐separated structure of PVC‐g‐PVP and the domain spacing increased from 21.4 to 23.9 nm with increasing grafting degree. All the membranes exhibited completely amorphous structure and high Young's modulus and tensile strength, as revealed by wide angle X‐ray scattering (WAXS) and universal testing machine (UTM). Permeation experimental results using a CO2/N2 (50/50) mixture indicated that as an amount of PVP in a copolymer increased, CO2 permeability increased without the sacrifice of selectivity. For example, the CO2 permeability of PVC‐g‐PVP with 36 wt% of PVP at 35°C was about four times higher than that of the pristine PVC membrane. This improvement resulted from the increase of diffusivity due to the disruption of chain packing in PVC by the grafting of PVP, as confirmed by WAXS analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of highly reactive polyisobutylene by selective polymerization with o‐cresol/AlCl3 initiating system
Authors: Zhang L. B. , Wu Y. X. , Zhou P. , Xu R. W. 
Published: February 2011

AbstractHighly reactive polyisobutylenes (HRPIBs) with very large proportion (up to 95 mol%) of exo‐double bond end groups and number average molecular weight (Mn) of 5400–8500 Dalton (Da) could be successfully synthesized by the selective cationic polymerization of isobutylene (IB) from the mixed C4 fraction feed using o‐cresol/AlCl3 as initiating system at −20°C. A possible mechanism was proposed for the cationic polymerization process. The presence of large weakly coordinating counteranion in propagating species could lead to decreasing the possibility of the side transfer reactions via carbenium ion arrangements. This o‐cresol/AlCl3 initiating system exhibited extremely high selectivity toward IB polymerization in the mixed C4 fraction feed and a good property for rapid β‐proton abstraction from CH3 in the growing polyisobutylenes (PIBs) chain ends. High extent of α‐double bond end groups in HRPIBs prepared in the mixed C4 fraction feed could be comparable to that in those commercially produced by cationic polymerization of IB in inert solvent (e.g. hexane). To our knowledge, this is the first example to achieve HRPIBs via completely selective polymerization of IB from C4 mixed feed with AlCl3‐based initiating system, providing a potentially practical process for its simplicity and low costs. Copyright © 2011 John Wiley & Sons, Ltd.
Precipitation polymerization of 2‐hydroxyethyl methacrylate in supercritical carbon dioxide
Authors: Wang Xiao‐Hu , Cao Li‐Qin , Zhang Li‐Juan , Wang Ji‐De 
Published: February 2011

AbstractWe report the successful precipitation polymerization of 2‐hydroxyethyl methacrylate (HEMA) in supercritical carbon dioxide (scCO2) at pressures ranging from 15 to 27 MPa utilizing 2, 2′‐azobisisobutyronitrile (AIBN) as a free radical initiator. The effects of the reaction pressure, initiator concentration, monomer concentration, reaction temperature, and reaction time were investigated. Analyses by scanning electron microscopy (SEM) indicated that in all reaction conditions, polymerization in the absence of stabilizer led to the formation of large aggregates of partially coalesced particles, with diameters of approximate 1–10 µm. Analyses by gel permeation chromatography (GPC) indicated that for the reaction pressure, initiator concentration, monomer concentration, reaction temperature, and reaction time studied there are appreciable effect on product molecular weight. Copyright © 2011 John Wiley & Sons, Ltd.
Comparison of three cross‐linking agents for imprinting diethylstilbestrol in solid‐phase extraction
Authors: Wang Yongxiang , Liu Qiuming , Rong Fei , Fu Degang 
Published: February 2011

AbstractMolecularly imprinted polymer (MIP) has been heavily studied for years. However, most efforts focused on functional monomer and particular study of cross‐linking agents on imprinting effect and pore structure is rare. In this paper, diethylstilbestrol (DES) imprinted polymers cross‐linked by three types of agents and their imprinting effects in solid‐phase extraction (SPE) were discussed. Evolution of UV spectral and simulation of cross‐linking agents or monomer mixed with DES revealed that there was a particular interaction between divinylbenzene and DES. Clear imprinting effects towards DES showed for divinylbenzene made imprinted polymer (DM), with imprinting factors up to 16.02 (STD = 2.20), while the other two imprinted polymers showed limited effects with imprinting factors of 4.95 (STD = 0.45) and 1.63 (STD = 0.54). Specific surface areas, pore volumes, and pore size distributions of the particles also confirmed that DM showed distinguished structure, and the average pore size of it was just fit the size of DES and bisphenol A (BPA), while no pore was found in divinylbenzene made blank polymer. Other imprinted and non‐imprinted polymers showed no pore or big pores relatively. These results show that the cross‐linking monomer is not merely an inert component for the MIPs, it could play a positive role in promoting interactions with the template to afford molecular recognition in imprinting DES. Copyright © 2011 John Wiley & Sons, Ltd.
Structural characterization and high‐temperature compressive creep of PTFE‐based composites filled with inorganic nanoparticles
Authors: Wang Zhichao , Kou Kaichang , Liu Zongwen , Zhang Dongna , Bi Hui , Chao Min , Zhao Qingxin 
Published: February 2011

AbstractThe PTFE‐based nanocomposites with various contents of inorganic nanoparticles (n‐AlN and n‐Si3N4) were prepared by cold compaction followed by free sintering. The results of scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction show that PTFE spherulite formed in the nanocomposites. When 2 wt% inorganic nanoparticles were added into the PTFE matrix, the crystallinity increased from 34.3% to 42.1% and 43.2%, respectively. Moreover, the interplanar distances for each crystal plane were enlarged and the grain sizes were smaller than that of pure PTFE. In addition, the mechanical and high‐temperature compressive creep properties were investigated. The results indicate that the introduction of inorganic nanoparticles largely increased the high‐temperature compressive creep resistance, and the maximal reduction of percentage of creep strain was up to 68%. The tensile strengths of the nanocomposites increased with increasing filler content when it was no more than 2%, and then decreased with the further increase of the filler content, whereas the elongations at break showed a reverse tendency. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and characterization of a novel terpolymer based on L‐lactide, glycolide, and trimethylene carbonate for specific medical applications
Authors: Davachi S. M. , Kaffashi B. , Roushandeh J. Mohammadi 
Published: February 2011

AbstractThe bioresorbable new terpolymers of L‐lactide, glycolide, and trimethylene carbonate were synthesized via ring‐opening polymerization reaction of the cyclic monomers using Stannous octoate as initiator. Glycolide and L‐lactide were prepared from their parent acids and then purified by multiple re‐crystallization from ethyl acetate. The thermal and mechanical properties of this polymer were characterized by means of thermogravimetry, differential scanning calorimetry, stress–strain measurements, and dynamic mechanical analysis. The glass transition temperature of the terpolymers changed from 33 to 51°C with composition in a predictable manner. The rheological properties of copolymers and molecular weight of each copolymer were determined showing good processability for making fibers. Using a mini‐extruder, it was possible to produce some filaments. The filaments produced at 140°C had appropriate ductility. The in vitro measurements, specifying the biological properties were also carried out. The sample with monomer composition LLA:GA:TMC = 60:34:6 showed a slower degradation rate than the one with LLA:GA:TMC = 54:34:12. The low‐toxicity bioresorbable terpolymers with good rheological and in vitro properties are the promising new materials for biomedical applications specially a new suture formulation. Copyright © 2011 John Wiley & Sons, Ltd.