bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of varied release kinetics of the osteogenic thrombin peptide TP508 from biodegradable, polymeric scaffolds on bone formation in vivo
Authors: Hedberg Elizabeth L. , Kroese‐Deutman Henriette C. , Shih Charles K. , Crowther Roger S. , Carney Darrell H. , Mikos Antonios G. , Jansen John A.
Published: January 2005

This study was designed to assess the influence of varied release kinetics of the osteogenic thrombin peptide TP508 from osteoconductive poly(propylene fumarate)‐based (PPF) composite scaffolds on bone formation in vivo. Four classes of scaffolds were constructed with different TP508 dosages (200, 100, or 0 μg) and release kinetics (large burst release, minimal burst release, or no release) and implanted in 15.0 mm segmental defects in rabbit radii. The animals were euthanized at 12 weeks and the implants were analyzed by light microscopy, histological scoring analysis, and histomorphometric analysis. Samples from all classes displayed bone growth within the pores of the scaffold near the edges of the defect. In areas where bone was not observed, the pores were filled with mostly fibrous tissue and exhibited minimal inflammatory response for all classes. In contrast to other scaffold classes, scaffolds containing a total dose of 200 μg TP508 and exhibiting a large burst release profile showed statistically more bone formation guided along the surface of the scaffold, with these scaffolds averaging 80% of the defect length bridged with bone compared to 10% or less bridged for the other scaffold classes. These results demonstrate that the extent of in vivo bone formation in response to controlled release from PPF‐composite scaffolds is determined by the release kinetics of the incorporated osteogenic peptide. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 343–353, 2005
Disparity of activation onset in sensory cortex from simultaneous auditory and visual stimulation: Differences between perfusion and blood oxygenation level‐dependent functional magnetic resonance imaging
Authors: Liu Ho‐Ling , Feng Ching‐Mei , Li Jinqi , Su Fan‐Chi , Li Ning , Glahn David , Gao Jia‐Hong
Published: January 2005

Purpose

To compare the temporal behaviors of perfusion and blood oxygenation level‐dependent (BOLD) functional magnetic resonance imaging (fMRI) in the detection of timing differences between distinct brain areas, and determine potential latency differences between stimulus onset and measurable fMRI signal in sensory cortices.

Materials and Methods

Inversion recovery (IR) spin‐echo echo‐planar imaging (EPI) and T2*‐weighted gradient‐echo EPI sequences were used for perfusion‐ and BOLD‐weighted experiments, respectively. Simultaneous auditory and visual stimulations were employed in an event‐related (ER) paradigm. Signal time courses were averaged across 40 repeated trials to evaluate the onset of activation and to determine potential differences of activation latency between auditory and visual cortices and between these scanning methods.

Results

Temporal differences between visual and auditory areas ranged from 90–200 msec (root‐mean‐square (RMS) = 134 msec) and from –80 to 930 msec (RMS = 604 msec) in perfusion and BOLD measurements, respectively. The temporal variability detected with BOLD sequences was larger between subjects and was significantly greater than that in the perfusion response (P < 0.04). The measured time to half maximum (TTHM) values for perfusion imaging (visual, 3260 ± 710 msec; auditory, 3130 ± 700 msec) were earlier than those in BOLD responses (visual, 3770 ± 430 msec; auditory, 3360 ± 460 msec).

Conclusion

The greater temporal variability between brain areas detected with BOLD could result from differences in the venous contributions to the signal. The results suggest that perfusion methods may provide more accurate timing information of neuronal activities than BOLD‐based imaging. J. Magn. Reson. Imaging 2005;21:111–117. © 2005 Wiley‐Liss, Inc.
Assessing adenoviral hammerhead ribozyme and small hairpin RNA cassettes in neurons: Inhibition of endogenous caspase‐3 activity and protection from apoptotic cell death
Authors: Bantounas Ioannis , Glover Colin P.J. , Kelly Stephen , Iseki Sachiko , Phylactou Leonidas A. , Uney James B.
Published: January 2005

Antisense technology, including ribozyme and small interfering RNA, is being developed to mediate the down‐regulation of specific intracellular genes. It was observed in this study that both antiluciferase ribozymes and short hairpin RNAs (shRNAs) could significantly reduce the activity of exogenously expressed luciferase in primary hippocampal neurons in a viral titer‐dependent manner. shRNAs were more effective gene‐silencing agents than ribozymes, although they exhibited some nonspecific gene‐silencing effects at high viral titers. We also attempted to increase ribozyme efficacy by using a woodchuck hepatitis posttranscriptional regulatory element (WPRE) in the ribozyme expression cassette. The results showed that adenoviral vectors encoding specific ribozymes could silence the cellular expression of luciferase and endogenous procaspase‐3 significantly. Furthermore, the antiprocaspase‐3 ribozyme was shown to inhibit staurosporine‐mediated cell death. The addition of a WPRE did not, however, increase or decrease ribozyme activity. As far as we are aware, this is the first example of adenovirally mediated delivery of hammerhead ribozymes being used to manipulate gene expression in primary neurons. The results therefore suggest that hammerhead ribozymes may be useful tools for studying neuronal gene function and have potential as therapeutic agents to treat CNS diseases. © 2005 Wiley‐Liss, Inc.
Identification of rat Gas7 isoforms differentially expressed in brain and regulated following kainate‐induced neuronal injury
Authors: Chang P.‐Y. , Kuo J.‐T. , Lin‐Chao Sue , Chao Chuck C.‐K.
Published: January 2005

The growth arrest‐specific gene 7 (Gas7) is expressed primarily in the brain and is necessary for the formation of neurite in cultured cerebellar preneurons. The endogenous rat Gas7 (rGas7) is transiently elevated before nerve growth factor‐promoted neurite outgrowths emerge in cultured PC12 cells. We report three Gas7 isoforms (a, b, and c) in rat tissues. Peptide microsequencing identified two Gas7 forms, rGas7‐a (38 kDa) and rGas7‐b (47 kDa). rGas7‐c can be predicted from a transcription variant by alternative splicing. Although two open reading frames were predicted, a cloned rGas7 cDNA encoded mostly rGas7‐a in mammalian cells. The overexpression of the rGas7 cDNA in PC12 cells sufficed to promote small lamellipodia‐ and filopodia‐like cell processes that resemble the initial stages of neurite formation. Three rGas7 isoforms were differentially expressed in all of the brain subregions. Only rGas7‐a was detected in rat cerebellum, as in mouse cerebellum. Kainate injury did not affect the level of rGas7‐b, but the level of isoform c was substantially suppressed in the hippocampus. Immunohistochemistry reveals that Gas7 was expressed primarily in the pyramidal neurons of the hippocampus and was quickly attenuated before recovery in the CA3 area after kainate was administered. These results suggest that differential expression and unique regulation of Gas7 isoforms in brain subregions may be important in specialized brain functions. Conservation of Gas7 isoforms by alternative splicing in mammals is also considered. © 2005 Wiley‐Liss, Inc.
Experimental and computational studies of the thermal decomposition of halon 1211
Authors: Yu Hai , Kennedy Eric M. , Uddin Md. Azhar , Sullivan Simon P. , Dlugogorski Bogdan Z.
Published: January 2005

Thermal pyrolysis of halon 1211 (CBrClF2), diluted in nitrogen, in a tubular alumina reactor, has been studied over the temperature range of 773–1073 K at residence times from 0.3 to 2 s. At temperatures below 973 K, the major products were CCl2F2, CBr2F2, C2Cl2F4, C2BrClF4, C2F4, and C2Br2F4. Further increasing temperature resulted in the formation of CBrF3, CClF3, and many other species whose formation necessitated the rupture of CF bonds. Coke formation was also observed on the surface of the reactor at high temperatures. A kinetic reaction scheme involving 16 species and 25 reaction steps was developed and applied to model the thermal pyrolysis of halon 1211 over the temperature range of 773–973 K. Sensitivity analysis suggests that the reaction CBrClF2 + CClF2→CCl2F2 + CBrF2 constitutes the major pathway for the decomposition of halon 1211 under the conditions investigated. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 134–146, 2005
Effects of mixed H2O‐CH3CN solvents on the rate of hydrazinolysis of N‐phenylphthalimide: Spectral and kinetic evidence for the occurrence of N‐aminophthalimide on the reaction path
Authors: Ariffin Azhar , Leng Sim Yoke , Lan Lai Chwee , Khan M. Niyaz
Published: January 2005

Kinetic study on the cleavage of N‐phenylphthalimide (NPhPT) in the presence of 0.05 M NH2NH2 and mixed H2O‐CH3CN solvents reveals the occurrence of reaction scheme

equation image

where A, B, C, C1, An, E, and F represent NPhPT, o‐CO−2C6H4CONHC6H5, o‐CONHNH2C6H4‐ CONHC6H5, N‐aminophthalimide, aniline, o‐CO−2C6H4CONHNH2, and o‐CONHNH2C6H4‐CONHNH2, respectively. But, in the presence of either nonbuffered ⩾0.20 M NH2NH2 hydrazine buffer of pH ∼7.30–8.26 with total buffer concentration ([Buf]T) of >0.02 M, further conversion of F to 2,3‐dihydrophthalazine‐1,4‐dione (DHPD) has been detected depending upon the length of the reaction time (t), the values of [Buf]T, and pH. It has been shown that the rate of conversion of C1 to F is much faster than that of C to C1 which is much faster than that of F to DHPD. The reaction step A → C involves general base (GB) catalysis, while step C → C1 seems to involve specific base–general acid (GA) and GB‐GB catalysis. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 147–161, 2005
Nanosecond Nd:YAG laser on dental enamel: compositional analysis
by X-ray fluorescence
Authors: Antunes A , Salvador V L R , Scapin M A , de Rossi W , Zezell D M
Published: January 2005

Non-invasive methods such as X-ray Fluorescence has
been applied to study of the distinct pathologies and
contamination levels analysis in various biological tissues among
them nails, hair, and tooth. On the other hand, several works have
demonstrated that the laser could be induced chemical and
morphological alterations on the enamel surface occupying an
important role as co-adjuvant in the caries disease prevention.
Here, we have combined X-ray fluorescence using Fundamental
Parameters method aiming to evaluate the variation in the chemical
contend. The Ca and P concentrations as well as the Ca/P ratio
were estimated in sound human and bovine enamel surface by X-ray
fluorescence (XRF). We also evaluated the effect of the lactic and
the acetic acids on the sound and irradiated bovine enamel surface
by Scanning Electron Microscopy (SEM) verifying the acid attack
changes in the sound and irradiated bovine enamel. The laser
parameters applied produced lower ablation depths, but sufficient
to induce compositional changes. Our results have indicating an
alteration statically significative to Ca/P ratio and also
indicated an increase in the Ca/P ratio for the irradiated groups
in comparison to sound groups. We also verified that the acid
attack is more pronounced to sound bovine enamel surface in
relation to irradiated to the bovine enamel surface indicating
that the nanosecond laser can be used to reduce the
demineralization process.
Liver transplantation for HELLP syndrome
Authors: Shames Brian D. , Fernandez Luis A. , Sollinger Hans W. , Chin Thomas L. , D'Alessandro Anthony M. , Knechtle Stuart J. , Lucey Michael R. , Hafez Reza , Musat Alexandru I. , Kalayoglu Munci
Published: January 2005

Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome is a rare complication of pregnancy that is associated with preeclampsia and may result in rupture of the liver. Although there have been case reports of liver transplantation for HELLP syndrome, the outcomes of transplantation for this rare indication have not been reported. Furthermore, the optimal management of complicated HELLP syndrome and indications for liver transplantation are unclear. Our objective was to review the national experience with liver transplantation for HELLP syndrome and to develop a comprehensive algorithm for the management of liver complications of HELLP syndrome, including indications for transplantation. A recent case from our institution is reported and the literature is reviewed. The results of liver transplantation for HELLP syndrome were analyzed from the United Network for Organ Sharing database. Between October 1987 and November 2003 there have been 8 deceased donor liver transplants performed for complications related to HELLP syndrome. As of the most recent follow-up, 6 of the 8 patients are alive, with both deaths occurring within 1 month of transplantation, and 2 patients have required retransplantation. This review supports that good results can be obtained with liver transplantation for patients with complicated HELLP syndrome that have either ongoing, uncontrolled hemorrhage or liver necrosis and failure. Patients with complicated HELLP syndrome are best managed at a center with expertise in liver transplantation. (Liver Transpl 2005;11:224–228.)
Amelioration of hypertrophic cardiomyopathy using nonsurgical septal ablation in a cirrhotic patient prior to liver transplantation
Authors: Paramesh Anil S. , Fairchild Ralph B. , Quinn Theresa M. , Leya Fred , George Magdalene , Van Thiel David H.
Published: January 2005

A 53-year-old male with hepatitis C cirrhosis, who had been refused liver transplantation because of hypertrophic cardiomyopathy (HC), underwent nonsurgical septal ablation using alcohol with resolution of his ventricular outflow obstruction. This patient was able to subsequently undergo a successful deceased donor liver transplantation. This is the first reported case of alcohol induced septal ablation being performed in a cirrhotic patient with HC. Such nonsurgical procedures may be attractive in cirrhotic patients who are refused access to liver transplantation because of high surgical risk. (LiverTranspl 2005;11:236–238.)
Temperature Dependence of the Oxygen Solubility in Acrylates and its Effect on the Induction Period in UV Photopolymerization
Authors: Scherzer Tom , Langguth Helmut
Published: January 2005

Summary: The influence of temperature on the kinetics of the UV photopolymerization of two diacrylates carried out under air was studied by real‐time FTIR‐ATR spectroscopy. In the temperature range up to 100 °C, the rate of polymerization obeys the Arrhenius law. The induction period was found to decrease with increasing temperature. It was shown that this decay is exclusively due to the decreasing solubility of oxygen in the acrylate. Moreover, from the induction period and the oxygen solubility, quantum yields of the α‐cleavage of some photoinitiators were estimated.

Induction period calculated from the solubility of oxygen in TPGDA in comparison with experimental data from RT‐FTIR measurements.

magnified image

Induction period calculated from the solubility of oxygen in TPGDA in comparison with experimental data from RT‐FTIR measurements.
Morphology and Deformation Behaviour of a Liquid Crystalline Polymer Containing Laterally Attached Pentaphenyl Rods
Authors: He Chaobin , Liu Puwei , Griffin Anselm C. , Smith Christopher W. , Evans Kenneth E.
Published: January 2005

Summary: The morphology and deformation behaviour of a liquid crystalline polymer consisting of both laterally attached transverse rods and terminally attached rods were studied. A plaque specimen of the polymer was prepared using the melt‐compression method, which exhibited highly anisotropic Poisson's ratio behaviour. In its through‐thickness direction, its Poisson's ratio was approximately 0.54, and in the in‐plane it was approximately 0.43. This anisotropic behaviour is explained by the anisotropic morphology of the polymer plaque resulting from its compression preparation. The high Poisson's ratio in the through‐thickness direction is due to the unusual chain structure of the polymer. A simple analytical model is presented to describe the non‐linear strain dependent Poisson's ratio behaviour of the material.

Representation of the arrangement of the main chain and transverse rod molecules, prior to, during, and at complete extension.

magnified image

Representation of the arrangement of the main chain and transverse rod molecules, prior to, during, and at complete extension.
Membranes Directly Prepared from Solutions of Unsubstituted Cellulose
Authors: Eckelt John , Wolf Bernhard A.
Published: January 2005

Summary: Starting from 5 wt.‐% solutions of a prehydrolysis kraft pulp ($\overline M _{\rm n}$ = 135 kg · mol−1) in the mixed solvent (dimethylacetamide + 7 wt.‐% LiCl) we have prepared cellulose membranes on different supports according to the phase inversion process using above all acetone (AC) and 2‐propanol as precipitants. In this context we have studied the phase behavior of the quasiternary system (DMAc+LiCl)/AC/cellulose. The obtained membranes are mechanically stable and in their mechanical and separation properties on the whole comparable to membranes consisting of regenerated cellulose. With respect to gas separation the ideal selectivity of CO2 in combination with N2 and O2 turns out to be opposite for the present membranes as compared with that consisting of regenerated cellulose. Ultrafiltration experiments performed with aqueous solutions of polyethylene oxide differing widely in their molar mass resulted in cut‐off molecular weights ranging from 3 to 9 kg/mol.

GPC analysis of the retentate and permeate for a membrane on a non‐woven fabric using AC as precipitant.

magnified image

GPC analysis of the retentate and permeate for a membrane on a non‐woven fabric using AC as precipitant.
Front Cover: Macromol. Mater. Eng. 1/2005
Authors: Dong Xiaochen , Wang Li , Wang Wenqin , Jiang Guohua , Chen Ying , Zhao Zhenrong , Wang Jianjun
Published: January 2005

Front Cover: The picture on the cover shows the nano‐polyethylene fibers with floccules prepared via ethylene extrusion polymerization in situ, using SBA‐15‐supported Cp2ZrCl2 catalytic system under atmospheric pressure.

Further details can be found in the Full Paper by X. Dong, L. Wang,* W. Wang, G. Jiang, Y. Chen, Z. Zhao, and J. Wang on page 31.
Back Cover: Macromol. Mater. Eng. 1/2005
Authors: Houshyar Shadi , Shanks Robert A. , Hodzic Alma
Published: January 2005

Back Cover: Flexural properties of a composite of poly(propylene) fibre and matrix, with different weave patterns. The underlying image shows an SEM image of the satin weave composite with the fibres still visible. The insert shows the satin fabric before compression moulding.

Further details can be found in the Full Paper by S. Houshyar, R. A. Shanks,* and A. Hodzic on page 45.
Carbonyl 13C transverse relaxation measurements to sample protein backbone dynamics
Authors: Mulder Frans A. A. , Akke Mikael
Published: January 2005

Carbonyl 13C relaxation experiments to study protein backbone dynamics have recently been developed. However, the effect of three‐bond 13C′–13C′ couplings on transverse relaxation measurements appears not to have been considered, and the potential to detect and quantify motions on the millisecond to microsecond time scale has not been fully explored. The present paper addresses these two issues. Simulations and experiments show that scalar couplings between adjacent backbone carbonyl carbon nuclei and between backbone and side‐chain carbonyl/carboxyl carbon atoms in Asp and Asn residues interfere with the accurate determination of transverse relaxation rates by Carr–Purcell–Meiboom–Gill or on‐resonance spin‐lock measurements. The use of off‐resonance radio‐frequency fields avoids efficient cross‐polarization, and offers a route towards accurate R1ρ measurements. In addition, this approach yields dispersion in the transverse relaxation rate as a function of the effective field when conformational exchange is present. In the case of calcium‐bound calbindin D9k, 13C′ off‐resonance R1ρ measurements yielded uniform values of R2 along the polypeptide chain, indicating homogeneous chemical shift anisotropies and restricted dynamics on the picosecond to nanosecond time scale. Variation of R2 as a function of the effective spin‐lock field strength was not observed for any residue, indicating the absence of large‐scale conformational changes of the protein backbone in the millisecond to microsecond time window. The absence of relaxation induced by internal motions on these wide‐ranging time scales reinforces the view that calcium‐loaded calbindin D9k is extremely rigid. In contrast, for the C‐terminal tryptic fragment of calmodulin containing the E140Q mutation we observed widespread exchange broadening. From the carbonyl transverse relaxation dispersion profile of Asp129 the exchange rate was determined to be 28 000 s−1. Copyright © 2003 John Wiley & Sons, Ltd.
Heteronuclear Overhauser experiments for symmetric molecules
Authors: Walker O. , Mutzenhardt P. , Canet D.
Published: January 2005

The nuclear Overhauser effect (NOE) arises from dipolar interactions between magnetic moments associated with nuclear spins and it has become a powerful tool to extract relevant pieces of structural information about small molecules, as well as in molecules of biological interest. As a consequence, accurate NOE measurement is a very crucial issue. Here, we present a comparison between direct and a new inverse HOESY experiment aimed at the detection of heteronuclear NOE between 1H and 13C, which is particularly well suited for symmetric compounds. It transpires that directly detected data are more suitable for quantitative assessment even if they suffer from lower sensitivity, whereas inverse detection is quite appropriate for a quick and qualitative assessment. In the latter experiment, unwanted cross‐correlation effects may hide valuable NOE data (cross‐relaxation), this drawback can be circumvented by a slight modification of the pulse sequence. Copyright © 2003 John Wiley & Sons, Ltd.
The search for autism disease genes
Authors: Wassink Thomas H , Brzustowicz Linda M , Bartlett Christopher W , Szatmari Peter
Published: January 2005

Autism is a heritable disorder characterized by phenotypic and genetic complexity. This review begins by surveying current linkage, gene association, and cytogenetic studies performed with the goal of identifying autism disease susceptibility variants. Though numerous linkages and associations have been identified, they tend to diminish upon closer examination or attempted replication. The review therefore explores challenges to current methodologies presented by the complexities of autism that might underlie some of the current difficulties, and finishes by describing emerging phenotypic, statistical, and molecular investigational approaches that offer hope of overcoming those challenges. © 2004 Wiley‐Liss, Inc. MRDD Research Reviews 2004;10:272–283.
Treating the core features of autism: Are we there yet?
Authors: Bodfish James W.
Published: January 2005

A wide variety of nonestablished treatments have been proposed as “cures” for the core features of autism and are used frequently despite having largely escaped scientific scrutiny. In contrast, a growing body of empirical evidence supports the use of a few forms of theory‐based and empirically validated treatment for some aspects of the core features of autism. These include behavioral/psychoeducational interventions and specific forms of medication treatment, which can produce significant improvements in communication, social interaction, and problem behaviors that both maintain over time and generalize across settings. While there is no doubt that treatment and educational services for persons with autism have improved over the past 6 decades, it also appears that significant issues remain with respect to (1) the routine application of validated treatments for the majority of cases with autism, (2) the resistance to even validated forms of treatment for a substantial minority of cases with autism, and (3) the extent to which validated treatments effectively treat the specific core features of autism that are most disabling for persons with autism and their families. © 2004 Wiley‐Liss, Inc. MRDD Research Reviews 2004;10:318–326.
Facially amphiphilic phenylene ethynylenes
Authors: Arnt Lachelle , Breitenkamp Rebecca B. , Tew Gregory N.
Published: January 2005

Facially amphiphilic poly(phenylene ethynylenes) were synthesized with various non‐polar alkyl and polar amine side chains by Sonogashira‐Hagihara coupling conditions. para‐Phenylene ethynylene derivatives with pentoxy and tertiary amine side chains were dissolved in organic solvent, such as toluene or 1,2,4‐trichlorobenzene, and introduced into an acidic, aqueous environment. The polymer molecules were found to self‐assemble and stabilize these oil‐water interfaces as visualized by confocal scanning laser microscopy. meta Derivatives containing dodecyl and primary amine side chains were also prepared and found to be active at the air‐water interface. When analyzed by Langmuir trough experiments, this polymer was found to have an area of approximately 45 Å2 per repeat unit, which correlates to an edge‐on orientation at the air‐water interface where the polar groups are immersed in the water sub‐phase and both the hydrocarbon backbone and dodecyl chains extend away from the interface. Due to the facially amphiphilic architecture and large hydrocarbon side chains, these polymers were found to self‐assemble from aqueous solutions into large aggregates with some order. Copyright © 2005 John Wiley & Sons, Ltd.
Nanoprocessing of polymers: applications in medicine, sensors, catalysis, photonics
Authors: Dersch R. , Steinhart M. , Boudriot U. , Greiner A. , Wendorff J. H.
Published: January 2005

Nanofibers and nanotubes based on polymers offer a broad range of applications in areas such as photonics, sensorics, catalysis or medicine and pharmacy. A set of preparation techniques which allow to introduce simultaneous specific functions into such nanoobjects has been developed recently. These include electrospinning and co‐electrospinning of nanofibers as well as template methods utilizing eletrospun nanofibers or porous substrates. These techniques yield infinitively long nanofibers and nanotubes with well defined aspect ratios respectively with diameters down to a few ten nanometers. These nanofibers and nanotubes can be functionalised, among others by using biodegradable materials or via the incorporation of nanoparticles or precursor molecules, in such a way that applications for tissue engineering, for catalysis, photonics and sensorics become available. Copyright © 2005 John Wiley & Sons, Ltd.
Polycarbonate/SiC nanocomposites—influence of nanoparticle dispersion on molecular mobility and gas transport
Authors: Böhning Martin , Goering Harald , Hao Ning , Mach Reinhard , Schönhals Andreas
Published: January 2005

Plasma synthesized silicon carbide (SiC) nanoparticles were dispersed in dichloromethane/poly(bisphenol‐A‐carbonate) (PC) solutions by high power ultrasonification. Samples were then prepared by film casting under well adapted preparation conditions.

The influence of the SiC nanoparticles on the molecular mobility of the PC is studied by dielectric relaxation spectroscopy. No effect on the cooperative segmental mobility (glass transition) was detected. But the relaxation region corresponding to localized fluctuations is strongly broadened and the activation energy is reduced with increasing nanoparticle concentration. The most significant change was observed in the relaxation region between α‐ and β‐process. The gas transport properties of these nanocomposite films are characterized in terms of permeability, diffusivity and solubility. Results can be interpreted based on an altered local free volume distribution and a change of molecular mobility of the polymer matrix near the nanoparticle surface which is in agreement with the dielectric results. Concentration dependent CO2 permeation experiments reveal a significant reduction of plasticization effects in the nanocomposites compared to the pure PC. Copyright © 2005 John Wiley & Sons, Ltd.
Processing‐interphase‐property relationship in fiber‐reinforced thermosetting‐matrix composites
Authors: Yang F. , Pitchumani R.
Published: January 2005

Fabrication of thermosetting‐matrix composites is based on a critical step of cure, which involves applying a predefined temperature cycle to a fiber‐resin mixture. Several temperature‐dependent mass transport processes occur in the vicinity of the reinforcement fiber, leading to the formation of an interphase region with different chemical and physical properties from the bulk resin. The cure cycles applied on the macroscopic boundaries of the composite govern the microscopic cure kinetics near the fiber surface, which in turn determines the interphase and composite properties. A predictive approach to directly linking the cure cycles and final composite properties is not presently available and is established for the first time in this paper. A multiscale thermochemical model is developed to predict the concentration profile evolution with time near fiber surfaces at various locations across the composite thickness. The concentration profiles at the gelation time are mapped to modulus profiles within the interphase region, and a finite element analysis is used to determine the overall composite modulus in terms of the constituent interphase, fiber, and matrix properties. Relevant numerical results are presented for the first time where the composite modulus is directly linked to the cure cycle and interphase formation parameters without assumed structures or properties of the interphase. The results provide useful information for selecting material components and cure cycles parameters to achieve desired interphase and composite properties. POLYM. COMPOS., 26:193–208, 2005. © 2005 Society of Plastics Engineers
Regression‐based model for elastic constants of 2D braided/woven open mesh angle‐ply composites
Authors: Carey J. , Munro M. , Fahim A.
Published: January 2005

The elastic constants of closed mesh braided/woven fabrics are generally obtained from finite element analysis, fabric geometry model, and modified classical laminate plate theory. These models are complex and often impractical for industrial design purposes and do not address the cases of open mesh braided/woven fabrics. This paper proposes an alternative to existing models and software packages. Simple regression‐based empirical equations were developed to obtain Ex, Ey, Gxy, and νxy of braided/woven fabrics at any angle‐ply angle using the braid/weave unit cell volume fraction (Vf0), the fiber volume fraction (Vf), and the elastic constants of an equivalent angle‐ply laminate (E, E, G, ν). Design equation predictions were verified by comparing them to a previously validated modified classical laminate plate theory (CLPT) model using various fiber/resin combinations. Excellent agreement was found for each set of results. POLYM. COMPOS., 26:152–164, 2005. © 2005 Society of Plastics Engineers
Improving services for people with diabetes: lessons from setting up the DREAM trial
Authors: Whitty P , Eccles MP , Hawthorne G , Steen N , Vanoli A , Grimshaw JM , Wood L , Speed C , McDowell D
Published: January 2005

The DREAM trial (a randomised, controlled trial of a patient‐based Diabetes REcall And Management system) was designed to evaluate the effectiveness and efficiency of an area‐wide ‘extended’ computerised diabetes register. This comprised a structured recall and management system, actively involving patients, and incorporating clinical management prompts to primary care clinicians based on locally‐adapted, evidence‐based guidelines. This paper presents the findings from the process of setting up and running the trial; important lessons have been learnt from producing the guidelines, introducing the new software into the diabetes register, and the early months of running the system. These points have implications for diabetes registers in general, and are of particular relevance to the implementation of the National Service Framework for Diabetes in England. In particular, most diabetes registers have not been used as recall systems, usually functioning as little more than data recording mechanisms. However, it is possible to develop diabetes register software that not only functions as a recall system, but also generates clinical management prompts based on guidelines, in response to a wide range of clinical variables entered onto the system. Copyright © 2004 John Wiley & Sons, Ltd.
Use of the rapid acting insulin analogue lispro and its protamine retarded form (Humalog Mix 25) in a clinical setting
Authors: Thaware P , Howe J , Lawrence IG , McNally PG , Davies MJ
Published: January 2005

We conducted a retrospective clinical audit of clinical outcomes (effect on glycaemic control, weight and rates of hypoglycaemia) in patients who were switched from premixed conventional insulin therapy to a premixed, biphasic preparation of a rapid acting insulin analogue (viz Humalog Mix 25 [HM25]) for one of the following reasons: poor long‐term glycaemic control/occurrence of hypoglycaemic episodes/complaints of weight gain. Our aim was to analyse clinical outcomes in these patients after 12 months of such therapy.

In total, 56 patients were identified over a 16‐month period. Clinical indications for the switch to HM25 were poor glycaemic control in 30, documented hypoglycaemic episodes in 19, and excessive weight gain while on insulin in two of these patients (the reason was not documented in the remaining five patients). The follow up was for 12‐months with outcomes compared at baseline (i.e. prior to the switch), at two to seven months and at eight to 12 months.

After eight to 12 months of therapy, there was an improvement of 0.98% in the overall mean HbA1c levels and of 1.2% in patients with poor glycaemic control (10.3% vs 9.1%; p=0.03). In those switched for occurrence of hypoglycaemia, the proportion still experiencing episodes fell from 100% at baseline to 36% at the end of eight to 12 months with only four of the initial 19 (21.05%) continuing to report any related symptoms.

When used in patients for certain specific problems, HM25 can improve long‐term glycaemic control and reduce the risk of hypoglycaemic episodes. Copyright © 2004 John Wiley & Sons, Ltd.
Transfer to a patient centred, carbohydrate counting and insulin matching programme in a shortened time frame
Authors: Oswald G , Kinch A , Ruddy E
Published: January 2005

Patients wishing to transfer to intensified insulin therapy through a shortened skills‐based learning programme were offered both an insulin matching carbohydrate counting programme (ICT) and continuous subcutaneous insulin infusion (CSII). In total 70 patients transferred to ICT following a median of 90 minutes of professional input. In a prospective audit, improved glycaemic control was maintained for one year on ICT (initial HbA1c 9.3±1.5%, 6/12 HbA1c 8.3±1.4%, n = 67, p<0.001; one year 8.3±1.4%, n=64, p<0.001). In 12 patients who switched to CSII after a period on ICT, a significant improvement in HbA1c was seen following ICT (pre‐ICT HbA1c 9.6±1.5%, post‐ICT HbA1c 8.3±1.4%, t = 2.9, p<0.02), but no further improvement was seen after a further year of CSII (HbA1c 8.4±0.8%, n = 9).

CSII does not appear to offer significant glycaemic control advantages over ICT in this programme. Patient satisfaction with both therapies is high, but the ease of transfer and success of ICT make this our preferred option. Copyright ©2004 John Wiley & Sons, Ltd.
Acromegaly presenting with diabetic ketoacidosis
Authors: Ogundpipe OA , Balaji HN , Blandford RL
Published: January 2005

The case of a 30‐year‐old woman presenting with diabetic ketoacidosis as a first manifestation of acromegaly is reported. This is an extremely rare and unusual presentation. The case illustrates the importance of insulin resistance due to growth hormone excess in the presence of relative insulin deficiency as a cause of diabetic ketoacidosis. Copyright © 2004 John Wiley & Sons, Ltd.
Are our insulins more or less predictable than our patients?
Authors: Barnett AH , Clarke Pat
Published: January 2005

Patients with insulin‐treated diabetes often report day‐to‐day variability in blood glucose levels. Suboptimal patient self‐management may often be considered the most likely cause, but studies have not consistently demonstrated a relationship between adherence and control. Patient behaviours such as insulin resuspension and dose setting technique will contribute to erratic glycaemic control, but because many patients who appear to adhere faithfully to their insulin regimens still report erratic, unpredictable blood glucose, it seems likely that limitations in the prescribed therapy itself might be at least partly causal. Indeed, studies investigating repeat doses of exogenous insulins have shown that the pharmacokinetic and pharmacodynamic profiles that follow each individual insulin injection can vary considerably from the overall mean profiles, both within and between patients. For traditional basal insulin preparations (such as NPH), this variability, combined with a peak in absorption, may contribute to nocturnal hypoglycaemia, which will limit the attainment of glycaemic targets. Recent biotechnological advances have, however, allowed insulin analogues with modified pharmacokinetic properties to be designed with the intent of improving post‐prandial or basal glycaemic control. For example, two analogue preparations (insulin glargine and insulin detemir) have recently been marketed and offer a protracted profile of action that is well suited to basal insulin substitution. Insulin detemir, for example, has been shown to offer greater within‐person predictability in duration of action and maximal effect than other basal insulins. Such improvements offer the potential to provide better and more predictable glucose control through modification of the insulin regimen as well as through the encouragement of improved patient self‐management techniques. Copyright © 2004 John Wiley & Sons, Ltd.
Ionic liquids as reaction media for polymerization processes: atom transfer radical polymerization (ATRP) of acrylates in ionic liquids
Authors: Biedroń Tadeusz , Kubisa Przemyslaw
Published: January 2005

Application of ionic liquids (organic salts that are liquid at ambient temperatures) as solvents for atom transfer radical polymerization (ATRP) of acrylic monomers is described. Ionic liquids dissolve several inorganic and organic compounds, are highly polar and non‐volatile. It has been shown that their application as solvents in ATRP of acrylates allows the reduction of side‐reactions when compared against bulk polymerizations. When chiral ionic liquid was used as a solvent a small but clear effect on polymer tacticity was observed. Copyright © 2003 Society of Chemical Industry
Synthesis of novel poly(vinyl methyl ether) copolymers by alkylation of poly(vinyl acetate) and poly(vinyl alcohol)
Authors: Markova Dilyana , Christova Darinka , Velichkova Rumiana
Published: January 2005

Poly[(vinyl methyl ether)‐co‐(vinyl alcohol)]s were synthesized from poly(vinyl acetate) and poly(vinyl alcohol) by a new simple method based on the well‐known Williamson reaction. The influence of the type of the alkylating agent and the reaction conditions on the efficiency of the methylation was investigated. A series of copolymers with different molecular weight and degree of alkylation were prepared and the lower critical solution temperature (LCST) behaviour of their aqueous solutions was evaluated by measuring the cloud‐point temperatures (Tcp). Copyright © 2003 Society of Chemical Industry
pH‐ and thermo‐responsive properties of poly(N‐vinylcaprolactam‐co‐acrylic acid) copolymers
Authors: Shtanko Nadejda I , Lequieu Wouter , Goethals Eric J , Du Prez Filip E
Published: January 2005

Copolymers with both pH‐ and thermo‐responsiveness were synthesized by free radical copolymerization of N‐vinylcaprolactam with small amounts of acrylic acid. The copolymers have been prepared in various solvents and characterized by gel permeation chromatography, Fourier‐transform infrared (FTIR) spectroscopy and titration. The phase separation behaviour of these copolymers was studied in water and buffered solutions at a variety of pH values and temperatures by means of attenuated total reflectance FTIR and cloud‐point measurements. The aqueous solutions of the copolymers showed a temperature, pH and molecular weight dependent phase‐separation behaviour. Copyright © 2003 Society of Chemical Industry
Effect of organoclay on the curing reactions in bismaleimide/diallyl bisphenol a resin
Authors: Hu Xiao , Meng Jiru
Published: January 2005

4,4′‐Bismaleimidodiphenyl methane (BMPM)/2,2′‐diallyl bisphenol A (DBA)/organoclay nanocomposites were synthesized. The effects of organoclays on the curing reactions in the BMPM/DBA system at low temperatures (ene reaction) and high temperatures (Diels–Alder reaction, homopolymerization of BMPM, and alternative copolymerization) were investigated with differential scanning calorimetry and Fourier transform infrared techniques. The results showed that these reactions were affected to different extents in the presence of organoclays. The ene reaction was accelerated to different degrees depending on the acidity of the modifier and the accessibility of the organoclays used. The exfoliation degree of organoclays in the prepolymers showed great effects on the curing behavior of BMPM/DBA. When an organoclay was less intercalated, the curing behavior of the system was different from that of neat BMPM/DBA. On the other hand, when the organoclay was better exfoliated in prepolymers, the curing behavior of the system was similar to that of the neat BMPM/DBA system. However, even in this case, the reactions at high temperatures occurred in different ways in the presence of an organoclay. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 994–1006, 2005
Anionic polymerization of styrenic macromonomers of polyisoprene, polybutadiene, and polystyrene
Authors: Vazaios Aggelos , Hadjichristidis Nikos
Published: January 2005

Anionic polymerization and high‐vacuum techniques were used to prepare a series of well‐defined polyisoprene, polybutadiene, and polystyrene polymacromonomers. The procedure involved (1) the synthesis of styrenic macromonomers in benzene by the selective reaction of the corresponding macroanion with the chlorine of 4‐(chlorodimethylsilyl)styrene (CDMSS) and (2) the in situ anionic polymerization of the macromonomer without previous isolation. The synthesis of the macromonomers [polyisoprene macromonomer: 11 samples, weight‐average molecular weight (Mw) = 1000–18,000; polybutadiene macromonomer: 5 samples, Mw = 2000–4000; and polystyrene macromonomer: 2 samples, Mw = 1300 and 3600] was monitored by size exclusion chromatography with refractive index/ultraviolet detectors. Selectivity studies with CDMSS indicated that polybutadienyllithum had the highest selectivity, and polystryryllithium the lowest. From kinetic studies it was concluded that the polymerization half‐life times were longer but comparable to those of styrene, and they appeared to only slightly depend on the molecular weight of the macromonomer chain (at least for low degrees of polymerization of the polymacromonomer and for Mw < 7000 for the macromonomer side chain). Dependence on the polymerization degree of the polymacromonomer product was also observed. All the prepared polymacromonomers were characterized by size exclusion chromatography with refractive index, ultraviolet and two‐angle laser light scattering detectors, and NMR spectroscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1038–1048, 2005
Synthesis and characterization of telechelic polymethacrylates via RAFT polymerization
Authors: Lima Vincent , Jiang Xulin , Brokken‐Zijp José , Schoenmakers Peter J. , Klumperman Bert , Van Der Linde Rob
Published: January 2005

The reversible addition–fragmentation chain transfer (RAFT) polymerization technique has been employed to synthesize linear α,ω ‐telechelic polymers with either hydroxyl or carboxyl end groups. Methyl methacrylate, butyl methacrylate, and butyl acrylate were polymerized with RAFT polymerization. The polymerizations exhibited the usual characteristics of living processes. Telechelic polymethacrylates were obtained from a hydroxyl monofunctional RAFT polymer with a two‐step chain‐end modification procedure of the dithioester end group. The procedure consisted of an aminolysis followed by a Michael addition on the resulting thiol. The different steps of the procedure were followed by detailed analysis. It was found that this route was always accompanied by side reactions, resulting in disulfides and hydrogen‐terminated polymer chains as side products next to the hydroxyl‐terminated telechelic polymers. Telechelic poly(butyl acrylates) with carboxyl end groups were produced in a single step procedure with difunctional trithiocarbonates as RAFT agents. The high yield in terms of end group functionality was confirmed by a new critical‐liquid‐chromatography method, in which the polymers were separated based on acid‐functionality and by mass spectrometry analysis. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 959–973, 2005
Alternative approach to the design of thermosensitive polymers: The addition of hydrophobic groups to the ends of hydrophilic polyether
Authors: Mori Takeshi , Shiota Yuuki , Minagawa Keiji , Tanaka Masami
Published: January 2005

We synthesized thermosensitive polymers by adding hydrophobic groups to the ends of a hydrophilic polyether, poly(ethylene oxide‐co‐propylene oxide). The cloud points of the polymers were controlled by the molecular weight of the polyether and the kind of hydrophobic end group. The polymers showed relatively sharp phase transitions, as observed by turbidimetry. The order of the cloud points of the polymers with various end groups did not follow that of the critical micelle concentrations of the polymers determined with fluorescence measurements with pyrene as a probe. The cloud points of the polymers linearly decreased with increasing concentrations of salts (Na2SO4 and Na3PO4). The slopes of the linear lines were almost constant, regardless of the kind of hydrophobic group and the molecular weight of the polyether. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1007–1013, 2005
Cationic polymerization of seven‐membered cyclic monothiocarbonate 1,3‐dioxepan‐2‐thione
Authors: Ochiai Bungo , Yoshii Kouichi , Nagai Daisuke , Endo Takeshi
Published: January 2005

The cationic ring‐opening polymerization of a seven‐membered cyclic monothiocarbonate, 1,3‐dioxepan‐2‐thione, produced a soluble polymer through the selective isomerization of thiocarbonyl to a carbonyl group {[SC(CO)O(CH2)4]n}. The molecular weights of the polymer could be controlled by the feed ratio of the monomer to the initiators or the conversion of the monomer during the polymerization, although some termination reactions occurred after the complete consumption of the monomer. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1014–1018, 2005