bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface‐Imprinted, Thermosensitive, Core‐Shell Nanosphere for Molecular Recognition
Authors: Ko Du Young , Lee Hwa Jeong , Jeong Byeongmoon
Published: August 2006

Summary: The D‐glucose imprinted core‐shell nanosphere with an average size of ≈60 to 80 nm showed a significant preference for the binding of D‐glucose than the non‐imprinted core‐shell nanosphere. Depending on temperature, the binding site in the shell with N‐isopropylacrylamide oligomer underwent a significant change in binding affinity. In addition, the D‐glucose imprinted core‐shell nanosphere showed a two times higher affinity for D‐glucose than L‐glucose, suggesting chiral recognition of the binding site. The core‐shell nanosphere reported here is a good biomimetic model system with a well‐defined morphology, high surface area, and variable binding affinity through a change in temperature.

D‐glucose imprinted core‐shell nanospheres showed excellent binding over the non‐imprinted core‐shell nanosphere.

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D‐glucose imprinted core‐shell nanospheres showed excellent binding over the non‐imprinted core‐shell nanosphere.
Cover Picture: Macromol. Rapid Commun. 16/2006
Authors: Mohan Y. Murali , Premkumar Thathan , Lee Kyungjae , Geckeler Kurt E.
Published: August 2006

Cover: Well dispersed silver nanoparticles were fabricated in hydrogels of poly[(N‐isopropylacrylamide)‐co‐(sodium acrylate)], in which the nanoparticles are stabilized by the polymer network. It has been demonstrated that the hydrogel network structure determines the size and shape of the nanoparticles and that they are very stable. Further details can be found in the article by Y. M. Mohan, T. Premkumar, K. Lee, and K. E. Geckeler* on page 1346.
Cover Picture: Macromol. Theory Simul. 7/2006
Authors: Dimitrov Dimitar I. , Milchev Andrey , Binder Kurt , Heermann Dieter W.
Published: August 2006

Cover: The picture on the cover shows short flexible polymers modeled as bead‐spring chains endgrafted on the wall (wall atoms are symbolized by green circles) of a cylindrical pore of diameter D. In part a) the chain length is N = 40, in part b) it is only N = 16, and different chains are visualized in different colors to distinguish them. Part c) points out that a chain (yellow) is not necessarily confined to the half‐cylinder containing its grafting site (blue) but can also extend into the opposite half‐cylinder (pink). As a consequence, the radial monomer density profile (lower part of c) exhibits a jump at the radial distance r = 0. This singularity disappears, however, when one uses the variable r′, defined in the figure, which is more naturally adapted to the tube geometry. Further details can be found in the article by D. I. Dimitrov,* A. Milchev, K. Binder, and D. W. Heermann on page 573.
Intestinal microbiota: A potential diet‐responsive prevention target in ApcMin mice
Authors: Mai Volker , Colbert Lisa H. , Perkins Susan N. , Schatzkin Arthur , Hursting Stephen D.
Published: August 2006

We previously reported that two dietary regimens, calorie restriction (CR) and a high olive oil‐containing diet supplemented with a freeze‐dried fruit and vegetable extract (OFV), reduced the development of intestinal adenomas in ApcMin mice by 57% and 33%, respectively, compared to control mice fed a defined diet ad libitum. The OFV diet was designed to have a strong effect on the composition of the intestinal microbiota through its high content of fiber, which represents a major source of fermentable substrate for the gut bacteria. We hypothesized that some of the observed effects of diet on intestinal carcinogenesis might be mediated by diet‐related changes in the bacterial species that thrive in the gut. Therefore, we determined by fluorescent in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) how the dietary interventions affected the composition of the intestinal microbiota, and we characterized specific microbiota changes that were associated with diet and reduced intestinal carcinogenesis. The OFV diet changed the overall composition of the intestinal microbiota, smaller changes were observed for the CR diet. Furthermore, we detected a 16S rDNA fragment associated with mice that did not develop polyps. Sequence analysis suggested that hitherto unidentified bacteria belonging to the family Lachnospiraceae (order Clostridiales) were its source. Thus, these bacteria may be an indicator of intestinal conditions associated with reduced intestinal carcinogenesis in ApcMin mice. © 2006 Wiley‐Liss, Inc.
CD97 overexpression in tumor cells at the invasion front in colorectal cancer (CC) is independently regulated of the canonical Wnt pathway
Authors: Wobus Manja , Huber Otmar , Hamann Jörg , Aust Gabriela
Published: August 2006

Invasion of colorectal carcinomas (CC) is characterized by nuclear accumulation of β‐catenin, a key component of the Wnt pathway, in scattered tumor cells. β‐catenin acts in cooperation with T‐cell factor (Tcf) HMG‐box transcription factors as a transcriptional activator of genes involved in tumor progression. Overexpression of CD97, a molecule that correlates with dedifferentiation and tumor stage in CC, parallels to nuclear translocation of β‐catenin. Here, we investigated whether CD97 is a direct β‐catenin/Tcf target gene. SW480 CC cells were used to mimic the phenotypical switch between central and invasive tumor areas. We demonstrate two‐fold higher CD97 expression and nuclear β‐catenin accumulation in cells grown at low density compared to cells cultured at high density, showing membrane‐associated β‐catenin. This suggests that CD97 expression correlates with the cellular localization of β‐catenin. However, CD97 mRNA expression levels were not affected by Tcf‐1 or Tcf‐4 as determined in inducible dominant‐negative (dn) Tcf CC cell lines. Furthermore, co‐expression of wildtype (wt) or S33A mutated β‐catenin with Tcf‐4 did not influence CD97 promoter activity. Inhibition of glycogen synthase kinase (GSK)‐3β, a negative regulator of the canonical Wnt pathway, had no influence on CD97 expression levels. In summary, enhanced CD97 expression in CC cells is regulated independent of β‐catenin/Tcf‐4, and is thus not a direct target of the canonical Wnt pathway. © 2006 Wiley‐Liss, Inc.
First Liapunov coefficient for coupled identical oscillators. Application to coupled demand–supply model
Authors: Rocşoreanu Carmen , Sterpu Mihaela
Published: August 2006

A general formula for the computation of the first Liapunov coefficient corresponding to the Hopf bifurcation in a four‐dimensional system of two coupled identical oscillators is performed for two cases. Only bi‐dimensional vectors are involved. Then a model of two coupled demand–supply systems, depending on four parameters is considered. A study of the Hopf bifurcation is done around one of the symmetrical equilibrium, as the parameters vary. The loci in the parameter space of the parameters values corresponding to subcritical, supercritical or degenerated Hopf bifurcation are found. The computation of the Liapunov coefficients is done using the derived formula. Numerical plots emphasizing the existence of different types of limit cycles are developed. Copyright © 2006 John Wiley & Sons, Ltd.
Multinomial permutations on a circle
Authors: Zimmels Yoram , Fel Leonid G.
Published: August 2006

Multinomial permutations on a circle are considered in the framework of combinatorics. Different cases are presented and shown to agree with previously derived formula for the number of cyclic necklaces. Two applied examples are discussed with a view to illustrate the implications of derived formulas. Copyright © 2006 John Wiley & Sons, Ltd.
Model‐based clustering using S‐PLUS
Authors: Leese Morven , Landau Sabine
Published: August 2006

Cluster analysis can be used to identify homogenous subgroups in many fields, including psychology and psychiatry. However, most clustering methods implemented in general‐purpose statistical packages are heuristic and can be criticized in principle for their lack of an underlying statistical model. Furthermore correlations between variables are generally ignored by standard methods. The question addressed here is whether currently available commercial software (S‐PLUS), which provides model‐based methods for clustering correlated continuous data, should be used for clustering data derived from questionnaires. Such data may be either continuous or ordinal in nature and typically exhibit correlations. Performance is assessed in this study on simulated data sets containing distinct multivariate normal subpopulations, both before and after mapping the simulated data onto an ordinal scale. A practical example showing how correlated data can be cluster‐analysed using these methods is given. The conclusion is that model‐based methods are certainly worthwhile for continuous data. However, their benefit, in particular their ability to deal with correlated data, is not marked for ordinal data. Simpler methods such as Ward's method may be almost as effective in this situation. Copyright © 2006 John Wiley & Sons, Ltd.
Role of gonadotropin‐releasing hormone (GnRH) in the regulation of gonadal differentiation in the gilthead seabream (Sparus aurata)
Authors: Soverchia L. , Carotti M. , Andreu‐Vieyra C. , Mosconi G. , Cannella N. , Habibi H. , Polzonetti‐Magni A.M.
Published: August 2006

It has been proposed that gonadotropin‐releasing hormone (GnRH) plays an autocrine/paracrine regulatory role in mammalian and fish ovaries. The marine teleost gilthead seabream is an interesting model since, during the life span of the fish, gonadal tissues develop first as testes, which then regress allowing the development of ovarian follicles. Recent studies carried out in ovaries of the gilthead seabream have demonstrated that various GnRH transcripts as well as GnRH splicing variants are expressed. The mRNA level of several GnRH forms in the female and male areas of the switching gonad, and their possible role in this process, were further investigated. The results here reported show that sGnRH, cGnRH‐II, and sbGnRH transcripts are locally expressed during gilthead seabream gonadal differentiation; the expression of the three GnRH forms was found to differ among the morphologically defined areas of the switching gonad, as demonstrated by applying reverse transcription‐polymerase chain reaction (RT‐PCR), together with in situ hybridization, and semiquantitative PCR analyses. Moreover, the hypothesis that GnRH forms may regulate testicular regression via an apoptotic mechanism was investigated by analyzing the different areas of switching gonads for caspase‐3 activity as a measure of apoptosis. Our results showed a marked increase of caspase‐3 activity in the area corresponding to the regressing testes in which a significant decrease of testosterone production was also found. The present findings demonstrate that the changes in the endogenous GnRH transcripts could be related with the gonadal differentiation in gilthead seabream, and that exogenous GnRH plays a role by stimulating apoptosis in the degenerating testis. Mol. Reprod. Dev. 74: 57–67, 2007. © 2006 Wiley‐Liss, Inc.
Strongylocentrotus drobachiensis oocytes maintain a microtubule organizing center throughout oogenesis: Implications for the establishment of egg polarity in sea urchins
Authors: Egaña Ana L. , Boyle Judith A. , Ernst Susan G.
Published: August 2006

Although it has been known for over a century that sea urchin eggs are polarized cells, very little is known about the mechanism responsible for establishing and maintaining polarity. Our previous studies of microtubule organization during sea urchin oogenesis described a cortical microtubule‐organizing center (MTOC) present during germinal vesicle (GV) migration in large oocytes. This MTOC was localized within the future animal pole of the mature egg. In this study we have used electron microscopy and immunocytochemistry to characterize the structure of this MTOC and have established that this organelle appears prior to GV migration. We show that the cortical MTOC contains all the components of a centrosome, including a pair of centrioles. Although a centrosome proper was not found in small oocytes, the centriole pair in these cells was always found in association with a striated rootlet, a structural remnant of the flagellar apparatus present in precursor germinal cells (PGCs). The centrioles/striated rootlet complex was asymmetrically localized to the side of the oocyte closest to the gonadal wall. These data are consistent with the previously proposed hypothesis that in echinoderms the polarity of the PGCs in the germinal epithelium influences the final polarity of the mature egg. Mol. Reprod. Dev. 74: 76–87, 2007. © 2006 Wiley‐Liss, Inc.
Temperature effects on sex determination and ontogenetic gene expression of the aromatases cyp19a and cyp19b, and the estrogen receptors esr1 and esr2 in atlantic halibut (Hippoglossus hippoglossus)
Authors: van Nes Solveig , Andersen Øivind
Published: August 2006

The aromatase (CYP19) and estrogen receptor (ESR) play important roles in the molecular mechanism of sex determination and differentiation of lower vertebrates. Several studies have proven these mechanisms to be temperature sensitive, which can influence the direction of phenotypic gender development. A temperature study was conducted to examine the effect of temperature on the sex differentiation in farmed Atlantic halibut. Sexually undifferentiated larvae were exposed to 7°C, 10°C, or 13°C during gonadal differentiation. Temperature effects on the transcription rate of the aromatase genes cyp19a (ovary type) and cyp19b (brain type) and the ESR genes esr1 and esr2 were examined by quantitative real‐time PCR. With increasing temperatures, both cyp19a mRNA levels and the female incidence showed a decreasing trend, thus strongly indicating a relation between the expression of cyp19a and morphological ovary differentiation. In contrast to cyp19a, the levels of cyp19b, esr1, and esr2 mRNA strongly increased in all temperature groups throughout the study period, and did not show obvious temperature‐related expression patterns. The present data provide evidence that posthatching temperature exposure significantly affects the expression of cyp19a mRNA during the developmental period and that high temperature possibly influences genetic sex determination in Atlantic halibut. Though, the female incidence never exceeded 50%, suggesting that only the homogametic (XX) female is thermolabile. So whereas temperature treatment is not likely suitable for direct feminization in halibut, the possibility for high‐temperature production of XX neomales for broodstock to obtain all‐female offspring by crossing with XX females is suggested. Mol. Reprod. Dev. 73: 1481–1490, 2006. © 2006 Wiley‐Liss, Inc.
Lambing rate using vitrified blastocysts is improved by culture with BSA and hyaluronan
Authors: Dattena M. , Mara L. , Bin T Ali A. , Cappai P.
Published: August 2006

Fatty acid‐free bovine serum albumin (BSAFAF) can be added to supplement medium used in the culture of sheep embryos. BSAFAF was able to support blastocyst and subsequent embryo development at rates equivalent to that of fetal calf serum (FCS)‐supplemented medium when fresh embryos were transferred. Furthermore, culture with BSAFAF significantly increased development of vitrified blastocysts transferred into synchronized sheep. The addition of the glycosaminoglycan, hyaluronan (HA) to the culture medium in the third and fifth day also increased cryo‐tolerance of blastocysts and in turn lambing rate was improved. Mol. Reprod. Dev. 74: 42–47, 2007. © 2006 Wiley‐Liss, Inc.
Motor neuron disease associated with copper deficiency
Authors: Weihl Conrad C. , Lopate Glenn
Published: August 2006

Copper deficiency in humans is a rare cause of myeloneuropathy that usually presents with a spastic ataxic gait, hyperreflexia, and distal sensory loss similar to that seen in patients with subacute combined degeneration. We describe three copper‐deficient patients, two of whom were referred with a presumptive diagnosis of amyotrophic lateral sclerosis, who had progressive asymmetric weakness or electrodiagnostic findings of proximal and distal denervation suggestive of lower motor neuron disease. Copper replacement resulted in stabilization or mild improvement in weakness. The clinical spectrum of human copper deficiency should include lower motor neuron disease in addition to a syndrome of spastic ataxia. Muscle Nerve, 2006
Fibroblast growth factor‐2 enhances functional recovery of reinnervated muscle
Authors: Iwata Yoshihisa , Ozaki Noriyuki , Hirata Hitoshi , Sugiura Yasuo , Horii Emiko , Nakao Estuhiro , Tatebe Masahiro , Yazaki Naoya , Hattori Tatsuya , Majima Masataka , Ishiguro Naoki
Published: August 2006

Long‐term denervation of muscles results in fibrosis and fat replacement, which prevent muscles from regaining contractile function despite reinnervation. Therefore, prevention of muscle atrophy between nerve repair and muscle reinnervation may improve the functional outcome. A variety of growth factors play significant roles in muscle mass modulation and muscle regeneration. The purpose of the present study was to investigate the effect of fibroblast growth factor‐2 (FGF2) and nerve growth factor (NGF) on muscle mass modulation after denervation and reinnervation using a nerve‐to‐muscle neurotization model. Growth factors were injected into the anterior tibial muscle after direct neurotization of muscles every 7 days up to 4 weeks after surgery. FGF2 significantly increased the amplitude of compound muscle action potentials (CMAPs), wet muscle weight, and the number of motor endplates, especially at higher concentration, compared to the vehicle. In contrast, NGF did not increase either the amplitude of CMAPs or muscle weight, although it significantly increased the number of motor endplates. These findings indicate that both growth factors enhance reinnervation of muscles; however, only FGF2 is involved in muscle mass modulation. Muscle Nerve, 2006
Applying discontinuous deformation analysis to assess the constrained area of the unstable Chiu‐fen‐erh‐shan landslide slope
Authors: Wu Jian‐Hong
Published: August 2006

Chiu‐fen‐erh‐shan landslide is a remarkable slope failure occurred during the Chi‐Chi earthquake in 1999. In November of 2002, abnormal geomorphologic features, including buckling and ground subsidence, were observed on the lower slope of the Chiu‐fen‐erh‐shan landslide. This study attempts to assess the constrained area of a future collapsing on the slope using a dynamic discrete numerical analysis method, discontinuous deformation analysis (DDA). The simulation results show that the depression in front of the toe of the slope provides a space for arresting the whole sliding rocks when only the unstable lower slope fails. However, as the whole slope slides, the rock fragments move farther into the memorial park and can impact other facilities resulting in the enlarging of constrained area. The authority should prohibit people from entrancing the constrained area in the rainy season. Copyright © 2006 John Wiley & Sons, Ltd.
Equilibrated patch recovery error estimates: simple and accurate upper bounds of the error
Authors: Díez Pedro , José Ródenas Juan , Zienkiewicz Olgierd C.
Published: August 2006

This paper introduces a new recovery‐type error estimator ensuring local equilibrium and yielding a guaranteed upper bound of the error. The upper bound property requires the recovered solution to be both statically equilibrated and continuous. The equilibrium is obtained locally (patch‐by‐patch) and the continuity is enforced by a postprocessing based on the partition of the unity concept. This postprocess is expected to preserve the features of the locally equilibrated stress field. Nevertheless, the postprocess phase modifies the equilibrium, which is no longer exactly fulfilled. A new methodology is introduced that yields upper bound estimates by taking into account this lack of equilibrium. This requires computing the ℒ︁2 norm of the error or relating it with the energy norm.

The guaranteed upper bounds are obtained by using a pessimistic bound of the error ℒ︁2 norm, derived from an eigenvalue problem. Nevertheless, these bounds are not sharp. An additional strategy based on a more accurate assessment of the error ℒ︁2 norm is introduced, providing sharp estimates, which are practical upper bounds as it is demonstrated in the numerical tests. Copyright © 2006 John Wiley & Sons, Ltd.
Particle simulation of spontaneous crack generation problems in large‐scale quasi‐static systems
Authors: Zhao Chongbin , Hobbs B. E. , Ord A. , Hornby P. , Peng Shenglin , Liu Liangming
Published: August 2006

To extend the application range of the distinct element method from a laboratory scale into a large scale such as a geological scale, we need to deal with an upscale issue associated with simulating spontaneous crack generation problems in large‐scale quasi‐static systems. Toward this direction, three important simulation issues, which may affect the quality of the particle simulation results of a quasi‐static system, have been addressed in details in this paper. The first simulation issue is how to determine the particle‐scale mechanical properties of a particle from the measured macroscopic mechanical properties of rocks. The second simulation issue is that the fictitious time, rather than the physical time, is used in the particle simulation of a quasi‐static problem. The third simulation issue is that the conventional loading procedure used in the distinct element method is conceptually inaccurate, at least from the force propagation point of view. A new loading procedure is proposed to solve the conceptual problem resulting from the third simulation issue. The proposed loading procedure is comprised of two main types of periods, a loading period and a frozen period. Using the proposed loading procedure, the parameter selection problem stemming from the first issue can be somewhat solved. Since the second issue is an inherent one, it is strongly recommended that a particle‐size sensitivity analysis of at least two different models, which have the same geometry but different smallest particle sizes, be carried out to confirm the particle simulation result of a large‐scale quasi‐static system. The related simulation results have demonstrated the usefulness and correctness of the proposed loading procedure for dealing with spontaneous crack generation problems in large‐scale quasi‐static geological systems. Copyright © 2006 John Wiley & Sons, Ltd.
A boundary condition in Padé series for frequency‐domain solution of wave propagation in unbounded domains
Authors: Song Chongmin , Bazyar Mohammad Hossein
Published: August 2006

A boundary condition satisfying the radiation condition at infinity is frequently required in the numerical simulation of wave propagation in an unbounded domain. In a frequency domain analysis using finite elements, this boundary condition can be represented by the dynamic stiffness matrix of the unbounded domain defined on its boundary. A method for determining a Padé series of the dynamic stiffness matrix is proposed in this paper. This method starts from the scaled boundary finite‐element equation, which is a system of ordinary differential equations obtained by discretizing the boundary only. The coefficients of the Padé series are obtained directly from the ordinary differential equations, which are not actually solved for the dynamic stiffness matrix. The high rate of convergence of the Padé series with increasing order is demonstrated numerically. This technique is applicable to scalar waves and elastic vector waves propagating in anisotropic unbounded domains of irregular geometry. It can be combined seamlessly with standard finite elements. Copyright © 2006 John Wiley & Sons, Ltd.
A case for Sherlock Holmes: forensic investigation of a gunshot wound to the head dating from Victorian London
Authors: Bailey J. , Mitchell P. D.
Published: August 2006

This is an investigation of a fatal gunshot wound that occurred over a century ago, in Victorian England. Records dating from 1900 show that it was regarded as suicide by officials of the time. Forensic, palaeopathological, and historical techniques are applied in order to determine whether the manner of death was suicide, murder, or accident. Comparison of the projectile trajectory with modern forensic series suggests that this case is statistically more likely to have been a murder than a suicide. This raises the possibility that a killer successfully staged events to appear as if a suicide had taken place. A summary is given of the important points to consider when interpreting gunshot trauma to the head in skeletal remains. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of time aids on independence and autonomy in adults with developmental disabilities
Authors: Arvidsson Gunnel , Jonsson Hans
Published: August 2006

The aim of this study was to describe how people with developmental disabilities experienced the use of time aids one year after their introduction by an occupational therapist. Data were obtained through semi‐structured interviews. The analysis was performed using a phenomenographic qualitative approach. The results showed that independence and autonomy should be considered as two separate phenomena. Increased independence did not always lead to increased autonomy or vice versa. Four different relationships between these two phenomena were found. They all illustrate the different priorities of the participants and different levels of independence and autonomy. Concerning the usability of time aids, the occupational therapist has to recognize the importance of having frequent communication with the client to understand the phenomena that may affect the use of the aids. The occupational therapist should always try to involve both the client and significant support persons while introducing time aids. Future research in time aids with clients with developmental disabilities could involve multiple interviews with participants combined with participant observations and interviews. Copyright © 2006 John Wiley & Sons, Ltd.
Cultural influences on occupational therapy practice in Singapore: a pilot study
Authors: Yang SuYi , Shek Mei Poh , Tsunaka Megumi , Lim Hua Beng
Published: August 2006

Over the past decades, numerous occupational therapy frameworks have been published and adopted in the West but there is little discussion of their applicability to Singapore. The purpose of this study was to examine the relevance and applicability of occupational therapy frameworks in Singapore. Data were gathered from nine highly experienced occupational therapists. Audio‐taped semi‐structured interviews were used to collect data. Qualitative methods were used in identifying five themes – independence, applicability of client‐centred practice, concepts of occupation/activity, client's areas of concern, and application of occupational therapy models to practice. The themes were discussed in the context of three broad areas: (1) the potential discrepancy between occupational therapy's philosophical base and clients' values, (2) mismatch between the occupational therapists' prescription of activity and the meaning of activities to clients, and (3) the potential conflict between the occupational therapy approach and the corporate culture in Singapore. One of the important results from the study was that in Singapore culture, clients generally did not believe that achieving independence was important and they expected to be taken care of by their families. Further research with a larger sample is necessary to explore how culture and societal values impact on occupational therapy practice in Singapore. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of 2,2′‐biphenol‐ and 1,1′bi(2‐napthol)‐based poly(ether sulfones) and copolymers by classical step‐growth polymerization and by entropically‐driven ring‐opening polymerization of macrocyclic oligomers
Authors: Ben‐Haida Abderrazak , Hodge Philip , Nisar Mohammed , Helliwell Madeleine
Published: August 2006

2,2′‐Biphenol‐ and (R/S)‐ and (R)‐1,1′‐bi(2‐naphthol)‐based polysulfones were synthesized by classical step‐growth polymerizations and by entropically‐driven ring‐opening polymerizations (ED‐ROPs) of the corresponding macrocyclic oligomers (MCOs). To facilitate comparisons, the polysulfone derived from 4,4′‐cyclohexylidenebisphenol was synthesized similarly. ED‐ROP was also used to prepare copolymers. The molecular weights obtained using ED‐ROP were generally higher than those obtained using the classical step growth method. The MCOs required as the starting materials for ED‐ROPs were prepared by classical high dilution syntheses using the biphenols and bis(4‐chlorophenyl)sulfone in the presence of base. The cyclic dimer from a high dilution synthesis using (R)‐1,1′‐bi‐2‐naphthol and the cyclic dimer from a similar synthesis using 4,4′‐cyclohexylidenebisphenol were isolated as pure compounds by column chromatography and the molecular structures determined by single crystal X‐ray diffraction. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and properties of magnetite/poly (aniline‐co‐8‐amino‐2‐naphthalenesulfonic acid) (SPAN) nanocomposites
Authors: Reddy Kakarla Raghava , Lee Kwang‐Pill , Gopalan Anantha Iyengar , Showkat Ali Md
Published: August 2006

Composites were prepared by incorporating magnetite (Fe3O4) nanoparticles into the matrix of a sulfonated polyaniline (SPAN) [poly(aniline‐co‐8‐amino‐2‐naphthalenesulfonic acid) PANSA] through chemical oxidative polymerization of a mixture of aniline and 8‐amino‐2‐naphthalenesulfonic acid in the presence of magnetite nanoparticles. The composite, magnetite/SPAN(PANSA) was characterized by means of transmission electron microscopy (TEM), X‐ray diffraction (XRD), elemental analysis (EA), Fourier transform infrared (FT‐IR) spectra, UV‐vis spectroscopy, thermogravimetric analysis (TGA), conductivity and magnetic properties measurements. TEM image shows that magnetite nanoparticles were finely distributed into the SPAN matrix. XRD pattern of the nanocomposite reveals the presence of additional crystalline order through the appearance of a sharp peak at ∼43° and 71°. Conductivity of the nanocomposite (0.23 S/cm) is much higher than pristine copolymer (1.97 × 10−2 S/cm). The results of FT‐IR and UV‐visible spectroscopy reveal the presence of molecular level interactions between SO groups in SPAN and magnetite nanoparticles in the composite. Copyright © 2006 John Wiley & Sons, Ltd.
New composite polymer electrolytes based on room temperature ionic liquids and polyether
Authors: Jiang Hui , Fang Shibi
Published: August 2006

Composite polymer electrolytes based on room temperature ionic liquids and polyether have been designed and synthesized. All room temperature ionic liquids which contain short poly(ethylene oxide) chains have good compatibility with the prepolymer, polyether based on polysiloxane. An ultraviolet polymerization method was utilized for the curing of the composite polymer electrolytes. The composite polymer electrolytes which are composed of the room temperature ionic liquids and polyether based on polysiloxane showed high ionic conductivity and high thermal stability. The ionic conductivity of the composite polymer electrolytes is nearly two magnitudes higher than those electrolytes with pure polyether based on polysiloxane. A maximum conductivity of 1.05 × 10−3 S/cm−1 is achieved at 30°C. Thermogravimetic analysis revealed scarcely any thermal weight loss at 80°C and thermal decomposition of the composite polymer electrolytes had not been observed up to 250°C. It retains electrochemical stable till 4.2 V which is acceptable. Copyright © 2006 John Wiley & Sons, Ltd.
Preparation and characterization of poly(ethylene terephthalate)/clay nanocomposites by melt blending using thermally stable surfactants
Authors: Costache Marius C. , Heidecker M. J. , Manias E. , Wilkie Charles A.
Published: August 2006

Poly(ethylene terephthalate) (PET)/clay nanocomposites were prepared by melt blending and their morphologies and properties were investigated through X‐ray diffraction, bright field transmission electron microscopy, thermogravimetric analysis and cone calorimetry. Three clays were comparatively studied—montmorillonite, hectorite and magadiite—all organically modified with thermally stable surfactants developed in this laboratory. Two such organic modifications were investigated, alkyl‐quinolinium surfactants and vinylbenzyl‐ammonium containing copolymers; both organic modifications combine high enough degradation temperature to allow for melt processing with PET, and also favorable thermodynamics for nanocomposite formation with PET. All nanocomposites showed about the same value for the peak heat release rate (PHRR). The amount of char increases after nanocomposite formation and this could account for the PHRRs. Copyright © 2006 John Wiley & Sons, Ltd.
The mechanism of cumene peroxidation catalyzed by cobalt(II)‐chelated copolymer
Authors: Wang Cheng‐Chien , Chen Hui‐Chun , Chen Chuh‐Yean
Published: August 2006

Cumene peroxide is an important oxidant in the chemistry industry; however, the conversion and selectivity of cumene peroxide are still not desirable in the practical preparation process because there are some side reactions occurring in the high conversion. Hence, the reaction mechanism is investigated by many researchers. Fortunately, the high catalysis performance polymeric catalyst for cumene peroxidation was successfully synthesized in a previous study, thus, the reaction mechanism is to be investigated in this study. Except for cumene peroxide, three by‐products, including acetophenone, 2‐phenyl‐2‐propanol, 1‐methylethenyl benzene of cumene peroxidation are identified from the results of high performance liquid chromatography (HPLC), gas chromatography mass spectroscopy (GC‐MS), H1‐NMR analysis. Furthermore, the mechanism of cumene peroxidation catalyzed by cobalt(II)‐chelated copolymer is also proposed herein. The initiation rate equation represents ri = k[cumene]1.0[polymer‐Co(II) complex]0.5 according to the kinetic study of cumene peroxidation catalyzed by metal‐chelated copolymer. Meanwhile, the activation energy of cumene peroxidation by metal‐chelated copolymer catalyst is 10.7 kcal/mol, which is located in the range of radical reactions. Copyright © 2006 John Wiley & Sons, Ltd.
Poly(propylene)/montmorillonite/polypyrrole composites: structure and conductivity
Authors: Mravčáková Miroslava , Omastová Mária , Pötschke Petra , Pozsgay András , Pukánszky Béla , Pionteck Jürgen
Published: August 2006

Poly(propylene)/montmorillonite/polypyrrole (PP/MMT/PPy) composites were prepared by oxidative polymerization of pyrrole in the presence of dispersed poly(propylene) (PP) and montmorillonite (MMT) particles in aqueous solution of an anionic surfactant, dodecylbenzenesulfonic acid (DBSA), or in water/methanol solution. During the oxidative polymerization of pyrrole the exfoliated MMT rearranges to multilayered MMT intercalated with polypyrrole (PPy). The degree of intercalation depends on the charge compensation of the negatively charged MMT‐layers. Favored interlayer distances have been detected by wide angle X‐ray scattering, which are independent of the amount of PPy formed in the system. Excess PPy is located at the surface of the multilayered structures of MMT as well as at the surface of the PP particles present. The composites were processed to flat sheets. Morphology and, therefore, electrical conductivity strongly depend on the type of processing, but also on the amount of conducting PPy present in the composite and on the reaction medium used for PPy synthesis. Higher conductivities and improved stability against shear are observed when MMT is present in the composite samples compared to samples devoid of MMT. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of sulfonic group on solubility parameters and solubility behavior of poly(2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Gong Chunli , Guan Rong , Shu Yao‐Chi , Chuang Fu‐Sheng , Tsen Wen‐Chin
Published: August 2006

An investigation on the effect of sulfonic group on solubility parameters and solubility behavior of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) is presented. Sulfonated PPO (SPPO) was prepared using chlorosulfonic acid as a sulfonating agent. The structure of SPPO was confirmed by FT‐IR, and the ion exchange capacity (IEC) of SPPO was accurately determined by conductometric titration and 1H‐NMR. The three‐dimensional solubility parameters of SPPO defined by Hansen were estimated by group contribution, and this approach was used to obtain the three coordinates of a solubility parameter in terms of: a dispersion part δd, a polar part δp and a hydrogen bonding part δh. The theoretical predications of solubility behavior were characterized using “soluble sphere” in three‐dimensional space. The estimated results were in accordance with the solubility experiments in different solvents. Copyright © 2006 John Wiley & Sons, Ltd.
The influence of ionic liquid's nature on free radical polymerization of vinyl monomers and ionic conductivity of the obtained polymeric materials
Authors: Vygodskii Yakov S. , Mel'nik Olga A. , Lozinskaya Elena I. , Shaplov Alexander S. , Malyshkina Inna A. , Gavrilova Nadejda D. , Lyssenko Konstantin A. , Antipin Mikhail Yu. , Golovanov Denis G. , Korlyukov Alexander A. , Ignat'ev Nikolai , Welz‐Biermann Urs
Published: August 2006

Various 1,3‐dialkylimidazolium and tetraalkylphosphonium ionic liquids (ILs), including novel ones, have been studied as reaction media for free radical polymerization of methyl methacrylate (MMA), acrylonitrile (AN) and 1‐vinyl‐3‐ethylimidazolium salts (ViEtIm+)Y−. The influence of IL's nature upon the polymer formulation was investigated. The use of different ionic liquids allows not only to obtain the polymers with high molecular weight (PMMA, ${\bar M}_w$ up to 5,770,000 g/mol; PAN, ${\bar M}_v$ up to 735,000 g/mol and poly[(ViEtIm+)Y−], $\bar M_z$ up to 1,130,000 g/mol) in high yields, but also to control the polymerization rate and molecular mass. The physicochemical characteristics, including mechanical properties, thermal stability and heat‐resistance of the obtained polymers were studied in order to compare with those of polymers prepared in a traditional media. It was found that elongation, tensile modulus and strength of PAN, which was synthesized in ionic liquid, are reliatively higher. The influence of IL's nature upon their ionic conductivity and the formation of conductive polymers from molten‐salt‐type vinyl monomers was investigated. Molecular design of the polymers simultaneously with the influence of IL's nature in order to achieve higher ionic conductivity is discussed. Flexible, transparent polymer films, obtained in different ways, show relatively high ionic conductivity (of about 10−5 S cm−1 at 20°C). Copyright © 2006 John Wiley & Sons, Ltd.
Assembled cation‐exchange/anion‐exchange polypyrrole layers as new simplified artificial muscles
Authors: Ochoteco Estibalitz , Pomposo Jose A. , Bengoechea Miguel , Grande Hans , Rodriguez Javier
Published: August 2006

A simplified artificial muscle has been constructed by assembling different polypyrrole structures in the same synthesis process. This produces not only “all‐polymeric” but rather a new generation of “all‐conducting‐polymer” artificial muscles, capable of moving in electrolytic media by an electrical current application with no evidence of delamination after several cycles. Suitable devices can be constructed for biomedical applications, based on this conducting polymer film. Copyright © 2006 John Wiley & Sons, Ltd.
Switch to an invasive growth phase in melanoma is associated with tenascin‐C, fibronectin, and procollagen‐I forming specific channel structures for invasion
Authors: Kääriäinen E , Nummela P , Soikkeli J , Yin M , Lukk M , Jahkola T , Virolainen S , Ora A , Ukkonen E , Saksela O , Hölttä E
Published: August 2006

Malignant melanomas are characterized by their high propensity to invade and metastasize, but the molecular mechanisms of these traits have remained elusive. Our DNA microarray analyses of benign nevi and melanoma tissue specimens revealed that the genes encoding extracellular matrix proteins tenascin‐C (TN‐C), fibronectin (FN), and procollagen‐I (PCOL‐I) are highly upregulated in invasive and metastatic melanomas. The expression and distribution of these proteins were further studied by immunohistochemistry in benign nevi, radially and vertically growing melanomas, sentinel node micrometastases, and macrometastases. TN‐C was increased in all invasive tumours and metastases, especially at invasion fronts, but not in benign nevi or non‐invasive melanomas. Significantly, the intensity of TN‐C staining correlated with metastasis to sentinel lymph nodes, better than tumour thickness (Breslow). Moreover, TN‐C, FN, and PCOL‐I appeared to co‐localize in the tumours and form tubular meshworks and channels ensheathing the melanoma cells. Our data suggest that melanoma invasion is associated with the formation of special channel‐like structures, providing a new concept, structured tumour cell spreading. Altogether, these data provide potential new prognostic markers and therapeutic targets/strategies for preventing melanoma dissemination. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Factors influencing laboratory workers' decisions to accept or decline anthrax vaccine adsorbed (AVA): results of a decision‐making study in CDC's anthrax vaccination program
Authors: Fowler Gabrielle L. , Baggs James M. , Weintraub Eric S. , Martin Stacey W. , McNeil Michael M. , Gust Deborah A.
Published: August 2006

Background

Laboratory technicians, laboratory supervisors, decontamination/remediation workers, and environmental investigators are at increased risk for repeated occupational exposure to Bacillus anthracis. In 2002, the Advisory Committee on Immunization Practices (ACIP) recommended pre‐exposure vaccination for these occupational groups.

Objectives

To determine (1) the factors that influenced an individual's decision to either accept or decline Anthrax Vaccine Adsorbed (AVA), and (2) if laboratory workers' concern about AVA safety was related to their information needs and trust in the information provided.

Methods

We conducted a decision‐making survey of 404 participants at 44 Laboratory Response Network laboratories located throughout the United States. All participants were enrolled between October 2002 and December 2004, and all were eligible to receive AVA according to the 2002 ACIP recommendations. Chi‐square tests and multivariate logistic regression were used in the analyses.

Results

The response rate of eligible individuals at participating laboratories was 94% (404/430). Sixty‐six percent of respondents accepted and 34% declined AVA. Laboratory workers who declined AVA were more likely to rate their risk of exposure to inhalation anthrax as low (OR = 6.9; 95%CI 1.7, 28.3), report being very concerned (OR = 4.1; 95%CI 1.8, 9.3) or concerned (OR = 2.0; 95%CI 1.3, 3.1) about the safety of the vaccine, report that they did not trust the information provided in the Vaccine Information Statement (VIS) (OR = 2.3; 95%CI 1.1, 4.5), and to be enrolled in the study during 2002 (OR = 24.7; 95%CI 6.4, 95.3) or 2003 (OR = 5.0; 95%CI 2.5, 9.8), the first 2 years of the study. Furthermore, we found a significant association between a participant's level of concern about the safety of AVA and their perception that they received enough information and/or trusted the information in the VIS.

Conclusions

Low perceived necessity, concern about the safety of the vaccine, and a lack of trust in the VIS were associated with the decision of laboratory workers to decline AVA. Results of this decision‐making study may be used to try to improve acceptance rates of AVA among persons considered at high risk, and may inform educational efforts for other adult vaccines. Copyright © 2006 John Wiley & Sons, Ltd.
Identification of commercial hake and grenadier species by proteomic analysis of the parvalbumin fraction
Authors: Carrera Mónica , Cañas Benito , Piñeiro Carmen , Vázquez Jesús , Gallardo José Manuel
Published: August 2006

Analysis of parvalbumin fractions through proteomic methodologies allowed the differential classification of ten commercial, closely related species of the family Merlucciidae. Muscle extracts from nine hake species of the genus Merluccius including two subspecies of Merluccius australis (australis and polylepsis) and one grenadier species Macruronus novaezelandiae with two populations (novaezelandiae and magellanicus) were evaluated by 2‐DE and MALDI‐TOF MS. 2‐DE demonstrated that the species tested displayed a low intra‐specific degree of polymorphism and the isoform patterns were noticeably species‐specific. MALDI‐TOF mass fingerprints showed clear differences in the pattern of peptides produced by tryptic digestion between the Merluccius and the Macruronus, making the genus differentiation possible. In addition, a selective peptide mass present in the spectra from certain hakes allowed its classification in two groups: Euro‐African and American hakes. Besides, some specific masses allowed a clearly individual identification for M. bilinearis, M. australis polylepsis, M. australis australis, M. productus, M. paradoxus and M. polli, while the rest of the hake species can be grouped in two clusters, comprising M. hubbsi and M. gayi in one and M. merluccius and M. capensis in the other.
Pilot study of the Human Proteome Organisation Brain Proteome Project: Applying different 2‐DE techniques to monitor proteomic changes during murine brain development
Authors: Stühler Kai , Pfeiffer Kathy , Joppich Cornelia , Stephan Christian , Jung Klaus , Müller Michael , Schmidt Oliver , van Hall Andre , Hamacher Michael , Urfer Wolfgang , Meyer Helmut E. , Marcus Katrin
Published: August 2006

The Human Proteome Organisation Brain Proteome Project aims at coordinating neuroproteomic activities with respect to analysis of development, aging, and evolution in human and mice and at analysing normal aging processes as well as neurodegenerative diseases. Our group participated in the mouse pilot study of this project using two different 2‐DE systems, to find out the optimal conditions for comprehensive gel‐based differential proteome analysis. Besides the assessment of the best methodical conditions the question of “How many biological replicate analyses have to be performed to get reliable statistically validated results?” was addressed. In total 420 differences were detected in all analyses. Both 2‐DE methods were found to be suitable for comprehensive differential proteome analysis. Nevertheless, each of the methods showed substantial advantages and disadvantages resulting in the fact that modification of both systems is essential. From our results we can draw the conclusions that for the future optimal quantitative differential gel‐based brain proteome analyses the sample preparation has to be slightly changed, the resolution of the first as well as the second dimension has to be advanced, the number of experiments has to be increased and that the 2D‐DIGE system should be applied.