bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the Crystallinity of Polyesters Derived from the Glycolysis of PET
Authors: Colomines Gaël , Lee Arie Van Der , Robin Jean‐Jacques , Boutevin Bernard 
Published: August 2006

AbstractSummary:The crystallinity of a glycolysate obtained by glycolysis of PET with diethylene glycol (DEG) was qualitatively studied by optical microscopy using a polarizer and quantitatively by X‐ray diffraction. Moreover, the rheological behavior of this glycolysate was also studied in relation with its crystallinity. New glycolysates obtained using oligoesters of different chemical structures as reagents were studied under the same conditions and they show the total absence of crystallinity. According to the structure of the diol or of the oligoester used, the glycolysate crystallinity can be induced or not.DSC analyses of different glycolysates.magnified imageDSC analyses of different glycolysates.
Synthesis of Multinuclear Pyridylimine Based Palladium(II) Complexes with a Functionalized Star Polystyrene Core and Evaluation of Their Catalytic Activity Towards Ethylene Oligomerization
Authors: Abraham Sinoj , Ha Chang‐Sik , Kim Il 
Published: August 2006

AbstractSummary: The synthesis of a novel series of multi‐nuclear macroligated pyridylimine based palladium(II) complexes conjugated to a synthetic star polymer core has been well‐described. Star shaped polystyrene with a finite number of arms were prepared by atom transfer radical polymerization (ATRP) and the chain ends were chemically modified in order to introduce the desired end functionality. Utilizing this polymer as organic supports for pyridylimine‐based ligands, palladium(II) complexes were synthesized. On activating with methylaluminoxane (MAO), this complex showed substantially high activity towards ethylene oligomerization, producing C4 and C6 compositions as major products. The plausible mechanistic insight concerning the process of ethylene oligomerization is also broached.An example of trinuclear pyridylimine based palladium(II) complex having a functionalized star polystyrene core.magnified imageAn example of trinuclear pyridylimine based palladium(II) complex having a functionalized star polystyrene core.
Synthesis of Porous Polyurea with Room‐Temperature Ionic Liquids via Interfacial Polymerization
Authors: Zhu Lining , Huang Chien‐Yueh , Patel Yamini H. , Wu Jing , Malhotra Sanjay V. 
Published: August 2006

AbstractSummary: Polyurea with exotic porous structures has been synthesized by the interfacial polymerization between hexane and a series of 1‐alkyl‐3‐methylimidazolium room‐temperature ionic liquids (ILs). Scanning electron microscopy micrographs of the polyurea show a macroporous morphology of aggregated polymer particles with sizes around 200 nm and pore sizes between 100 to 500 nm. The geometry of the polymer particles and the pore size vary with the ILs employed. X‐Ray diffraction shows ionic‐liquid‐induced suppression of 3D crystalline order in the polyurea products. The microstructures of the polymer together with the FT‐IR results suggest that the observed exotic polymer morphology originates from interactions between the ionic liquid and the polymer.SEM micrograph of the interconnected macroporous structure of the polyurea formed in [C2mim][BF4] ionic liquid. The scale bar is 100 nm.magnified imageSEM micrograph of the interconnected macroporous structure of the polyurea formed in [C2mim][BF4] ionic liquid. The scale bar is 100 nm.
Surface‐Imprinted, Thermosensitive, Core‐Shell Nanosphere for Molecular Recognition
Authors: Ko Du Young , Lee Hwa Jeong , Jeong Byeongmoon 
Published: August 2006

AbstractSummary: 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.magnified imageD‐glucose imprinted core‐shell nanospheres showed excellent binding over the non‐imprinted core‐shell nanosphere.
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

AbstractWe 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

AbstractInvasion 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

AbstractA 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

AbstractMultinomial 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

AbstractCluster 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

AbstractIt 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

AbstractAlthough 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

AbstractThe 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

AbstractFatty 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

AbstractCopper 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

AbstractLong‐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

AbstractChiu‐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

AbstractThis 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.