bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic MR assessment of the anorectal angle and puborectalis muscle in pediatric patients with anismus: Technique and feasibility
Authors: Chu Winnie C.W. , Tam Yuk‐him , Lam Wynnie W.M. , Ng Alex W.H. , Sit Frances , Yeung Chung‐kwong 
Published: April 2007

AbstractPurposeTo assess the feasibility of dynamic breath‐hold MRI for evaluating changes in the anorectal angle and movements of the pelvic‐floor musculature (puborectalis) during resting and straining states in pediatric patients presenting with anismus.Materials and MethodsSix pediatric patients (7–13 years old) with chronic constipation and manometric evidence of anismus were assessed by dynamic breath‐hold MRI. Changes in the anorectal angle, the degree of pelvic‐floor descent, and the thickness and length of the puborectalis muscles were measured during rest and straining. The findings were compared with those obtained in six age‐ and sex‐matched controls.ResultsThe children with anismus had a smaller anorectal angle during straining, and the angle decreased from rest to defecation. The puborectalis also became paradoxically shortened and thickened during straining in the anismus group. There were significant differences between the two groups in terms of the change of degree of the anorectal angle, and the thickness and length of the puborectalis muscle during straining.ConclusionFast dynamic MRI is feasible for evaluating pelvic‐floor movement in pediatric patients. Preliminary results suggest that children with anismus have a smaller anorectal angle and a different puborectalis configuration compared to controls. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Combining Krylov subspace methods and identification‐based methods for model order reduction
Authors: Heres P. J. , Deschrijver D. , Schilders W. H. A. , Dhaene T. 
Published: April 2007

AbstractMany different techniques to reduce the dimensions of a model have been proposed in the near past. Krylov subspace methods are relatively cheap, but generate non‐optimal models. In this paper a combination of Krylov subspace methods and orthonormal vector fitting (OVF) is proposed. In that way a compact model for a large model can be generated. In the first step, a Krylov subspace method reduces the large model to a model of medium size, then a compact model is derived with OVF as a second step. Copyright © 2007 John Wiley & Sons, Ltd.
2‐methoxyestradiol induces apoptosis and cell cycle arrest in human chondrosarcoma cells
Authors: Fong Yi‐Chin , Yang Wei‐Hong , Hsu Sheng‐Feng , Hsu Horng‐Chaung , Tseng Kuo‐Fung , Hsu Chin‐Jung , Lee Chun‐Yi , Scully Sean P. 
Published: April 2007

Abstract2‐Methoxyestradiol (2ME) is an endogenous metabolite with estrogen receptor‐independent anti‐tumor activity. The current study seeks to determine the mechanism of anti‐tumor activity of 2ME on human chondrosarcoma. 2ME caused a time‐ and dose‐dependent cytotoxity in chondrosarcoma cells, while primary chondrocytes were minimally affected. Cells accumulated in G0/G1 phase in response to 2ME and DAPI stain indicated an induction of apoptosis. Bax, Cytochrome C, and Caspase‐3 protein expression were increased, while p53 expression was decreased. A higher Bax/Bcl‐2 ratio followed 2ME treatment. 2ME has a potentially promising role as a systemic therapy of chondrosarcoma when the mechanism of action is better delineated. Published by Wiley Periodicals, Inc. J Orthop Res 25:1106–1114, 2007
Global minimum and orthogonality in Cp‐classes
Authors: Mecheri Salah 
Published: April 2007

AbstractIn this paper we use recent results [14] to establish various characterizations of the global minimum of the map Fψ : U → ℝ+ defined by Fψ (X) = ‖ψ (X)‖p (1 < p < ∞) where ψ: U → Cp is a map defined by ψ (X) = S +ϕ (X), with ϕ: B (H) → B (H) a linear map and S ∈ Cp , and U = {X ∈ B (H): ϕ (X) ∈ Cp }. Further, we apply these results to characterize the operators which are orthogonal to the range of elementary operators. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the structure of the essential spectrum for the three‐particle Schrödinger operators on lattices
Authors: Albeverio Sergio , Lakaev Saidakhmat N. , Muminov Zahriddin I. 
Published: April 2007

AbstractA system of three quantum particles on the three‐dimensional lattice ℤ3 with arbitrary dispersion functions having not necessarily compact support and interacting via short‐range pair potentials is considered. The energy operators of the systems of the two‐and three‐particles on the lattice ℤ3 in the coordinate and momentum representations are described as bounded self‐adjoint operators on the corresponding Hilbert spaces. For all sufficiently small values of the two‐particle quasi‐momentum k ∈ (–π, π ]3 the finiteness of the number of eigenvalues of the two‐particle discrete Schrödinger operator hα (k) below the continuous spectrum is established. The location of the essential spectrum of the three‐particle discrete Schrödinger operator H (K), K ∈ (–π,π ]3 being the three‐particle quasi‐momentum, is described by means of the spectrum of the two‐particle discrete Schrödinger operator hα (k), k ∈ (–π, π ]3. It is established that the essential spectrum of the three‐particle discrete Schrödinger operator H (K), K ∈ (–π, π ]3, consists of finitely many bounded closed intervals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lp estimates of solutions tomixed boundary value problems for the Stokes system in polyhedral domains
Authors: Maz'ya V. , Rossmann J. 
Published: April 2007

AbstractA mixed boundary value problem for the Stokes system in a polyhedral domain is considered. Here different boundary conditions (in particular, Dirichlet, Neumann, free surface conditions) are prescribed on the faces of the polyhedron. The authors prove the existence of solutions in (weighted and non‐weighted) Lp Sobolev spaces and obtain regularity assertions for weak solutions. The results are based on point estimates of Green's matrix. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A hierarchical analysis of the green consciousness of the Egyptian consumer
Authors: Mostafa Mohamed M. 
Published: April 2007

AbstractThis study investigates the influence of various cultural values and psychological factors on the green purchase behavior of Egyptian consumers. Using a large sample of 1093 consumers, a conceptual model has been developed. The survey results provide reasonable support for the validity of the proposed model. Specifically, the findings from the structural equation model confirm the influence of the consumers' natural environment orientation, ecological knowledge, and environmental concern on their attitudes towards green purchase. Consumers' attitudes toward green purchase, in turn, are also found to affect their actual green purchase behavior via the mediator role of green purchase intention. However, one of the other important findings suggests that the link between intention and actual purchase is weak. In other words, on a declarative level, more and more consumers in Egypt express their concern over the ecological situation and declare their willingness to contribute somehow to the protection of environment by buying green products. However, in reality this concern may not be manifested consistently. © 2007 Wiley Periodicals, Inc.
Chemoenzymatic Synthesis of Amylose‐Grafted Chitosan
Authors: Matsuda Shun‐ichi , Kaneko Yoshiro , Kadokawa Jun‐ichi 
Published: April 2007

AbstractAn amylose‐grafted chitosan has been synthesized by a chemoenzymatic method according to the following two reactions. First, maltoheptaose is introduced to chitosan by a reductive amination using sodium cyanotrihydroborate in a mixed solvent of 1.0 mol · L−1 aqueous acetic acid and methanol at room temperature to produce a maltoheptaose‐grafted chitosan that has a well‐defined molecular structure. A phosphorylase‐catalyzed enzymatic polymerization of α‐D‐glucose 1‐phosphate is then performed from the maltoheptaose‐grafted chitosan to obtain the amylose‐grafted chitosan. This material does not dissolve in any solvent, e.g., aqueous acetic acid and dimethyl sufoxide, which are good solvents for chitosan and amylose, respectively.magnified image
A Facile Route to Synthesize Highly Uniform Nanocapsules: Use of Amphiphilic Poly(acrylic acid)‐block‐polystyrene RAFT Agents to Interfacially Confine Miniemulsion Polymerization
Authors: Lu Fujun , Luo Yingwu , Li Bogeng 
Published: April 2007

AbstractMiniemulsion polymerization with an amphiphilic poly(acrylic acid)‐block‐polystyrene reversible addition–fragmentation chain transfer agent as a surfactant and polymerization mediator is used to synthesize highly uniform nanocapsules. The nanocapsules with uniform structures, which include particle size, shell thickness, and shape symmetry, could be achieved by the post‐addition of a small amount of sodium dodecyl sulfate. Although the solid particles seem unavoidable, the ‘pure’ uniform core–shell structures are easily collected by centrifugation.magnified image
Polysorbate 80 as a Tool: Synthesis of Gold Nanoparticles
Authors: Premkumar Thathan , Kim Dongsik , Lee Kyungjae , Geckeler Kurt E. 
Published: April 2007

AbstractThe preparation of metal nanoparticles generally requires the use of mostly toxic reducing agents according to state‐of‐the‐art procedures. Here, we report that polysorbate 80, a polymeric nonionic surfactant, when reacted with a gold salt in water at room temperature, yields well‐dispersed gold nanoparticles. Furthermore, we could control the particle size by simply altering concentration or temperature. The synthetic procedure presented here is easy, inexpensive, straightforward, and user‐friendly.magnified image
Ductile‐to‐Semiductile Transition in PP‐MWNT Nanocomposites
Authors: Satapathy Bhabani K. , Ganß Martin , Weidisch Roland , Pötschke Petra , Jehnichen Dieter , Keller Thomas , Jandt Klaus D. 
Published: April 2007

AbstractA ductile‐to‐semiductile transition in the crack resistance behaviour of PP/MWNT composites is discussed, using an essential work of fracture approach based on a post yield fracture mechanics concept and its possible interrelation to the structural attributes studied by TEM, SEM, and WAXD. A maximum in the non‐essential work of fracture is observed at 0.5 wt.‐% MWNT content, which demonstrates the enhanced resistance to crack propagation compared to pure PP, followed by a sharp decline with the increase in MWNT content to 1.5 wt.‐%, which reveals a ductile‐to‐semiductile transition. Fracture kinetic studies present a qualitative picture of the nature of such a transition in terms of a) switch over from non‐steady (in pure PP) to steady‐state crack tip opening displacement rate (in nanocomposites), and b) a ductile‐to‐semiductile transition; largely as a result of delayed‐yielding of the nanocomposites.magnified image
Stabilization of Silver Nanoparticles by Polyelectrolytes and Poly(ethylene glycol)
Authors: Radziuk Darya , Skirtach Andre , Sukhorukov Gleb , Shchukin Dmitry , Möhwald Helmuth 
Published: April 2007

AbstractSilver nanoparticles of 23 nm size were formed by chemical reduction of silver nitrate in excess of aqueous sodium borohydride. To examine the aggregation behavior in NaCl solutions, they were coated with poly(diallyldimethylammonium chloride), poly(allylamine hydrochloride) and poly(ethylene glycol) by layer‐by‐layer assembly. Silver nanoparticles coated with PDADMAC of both high and low molecular weight revealed the lowest stability independent of salt concentration. Silver nanoparticles coated with PAH and PEG are stable in 0.1 or 0.01 M NaCl, whereas addition of 0.5 M NaCl destroys the colloidal solution. The destruction of silver agglomerates and the increase of monodispersity in the case of PEG coated silver nanoparticles were observed after heating at 90 °C. In contrast, uncoated silver nanoparticles readily agglomerate and precipitate even after heating at 65 °C.magnified image
Applications of mass spectrometry for the structural characterization of recombinant protein pharmaceuticals
Authors: Srebalus Barnes Catherine A. , Lim Amareth 
Published: April 2007

AbstractTherapeutic proteins produced using recombinant DNA technologies are generally complex, heterogeneous, and subject to a variety of enzymatic or chemical modifications during expression, purification, and long‐term storage. The use of mass spectrometry (MS) for the evaluation of recombinant protein sequence and structure provides detailed information regarding amino acid modifications and sequence alterations that have the potential to affect the safety and activity of therapeutic protein products. General MS approaches for the characterization of recombinant therapeutic protein products will be reviewed with particular attention given to the standard MS tools available in most biotechnology laboratories. A number of recent examples will be used to illustrate the utility of MS strategies for evaluation of recombinant protein heterogeneity resulting from post‐translational modifications (PTMs), sequence variations generated from proteolysis or transcriptional/translational errors, and degradation products which are formed during processing or final product storage. Specific attention will be given to the MS characterization of monoclonal antibodies as a model system for large, glycosylated, recombinant proteins. Detailed examples highlighting the use of MS for the analysis of monoclonal antibody glycosylation, deamidation, and disulfide mapping will be used to illustrate the application of these techniques to a wide variety of heterogeneous therapeutic protein products. The potential use of MS to support the selection of cell line/clone selection and formulation development for therapeutic antibody products will also be discussed. © 2007 Wiley Periodicals, Inc., Mass Spec Rev
Increase of the trophoblast giant cells with prolactin‐releasing peptide (PrRP) receptor expression in p53‐null mice
Authors: Komatsu Daisuke , Abe Takumi , Sano Yoshihiro , Shimazaki Kiyoe , Tomita Motowo , Kanayama Naohiro , Takahashi Katsuhiko 
Published: April 2007

AbstractTrophoblast giant cells in the mouse placentas are polyploid cells that form as a result of endoreduplication. The giant cells form the outermost layer of the extraembryonic compartment and produce a number of pregnancy‐specific hormones, including prolactin family members. Here we demonstrate that trophoblast giant cells are increased, and display upregulation of prolactin releasing peptide (PrRP) receptor in the p53‐null (p53−/−) embryonic placentas. At day 13.5 of gestation, the weight of p53−/− placentas was less than that of both wild‐type and p53+/− placentas. In p53−/− placentas, the spongiotrophoblast layer was significantly decreased in thickness, and the trophoblast giant cells were observed not only in the outer layer of placentas but in both the spongiotrophoblast layer and the labyrinthine layer. The giant cells spread over the spongiotrophoblast and labyrinthine layer in p53−/− placentas displayed more intensive expression of immunoreactive PrRP receptor than in wild‐type placentas. Previous studies indicated that the association between PrRP and PrRP receptor physiologically involves in the expression and secretion of the peptide hormones, including prolactin and growth hormones. These results suggest that p53 may regulate the differentiation of trophoblast giant cells, and may control the physiological PrRP stimuli in mouse placentas. Mol. Reprod. Dev. 74: 1089–1094, 2007. © 2007 Wiley‐Liss, Inc.
Protein kinase C activity in mouse eggs regulates gamete membrane interaction
Authors: Akabane Hiroto , Fan Jun , Zheng Xuehai , Zhu Guo‐Zhang 
Published: April 2007

AbstractGamete membrane interaction is critical to initiate the development of a new organism. The signaling pathways governing this event, however, are poorly understood. In this report, we provide the first evidence that protein kinase C activity in mouse eggs plays a crucial role in the regulation of this process. Stimulating PKC activity in mouse eggs by phorbol 12‐myristate 13‐acetate (PMA) drastically inhibited the egg's membrane ability to bind and fuse with sperm. Surprisingly, this significant reduction of gamete membrane interaction was also observed in eggs treated with the PKC inhibitors staurosporine and calphostin c. In further analysis, we found that while no change of egg actin cytoskeleton was detected after either PMA or calphostin c treatment, the structural morphology of egg surface microvilli was severely altered in the PMA‐treated eggs, but not in the calphostin c‐treated eggs. Moreover, sperm, which bound but did not fuse with the eggs treated with the anti‐CD9 antibody KMC8, were liberated from the egg membrane after PMA, but not calphostin c, treatment. Taken together, these results suggest that egg PKC may be precisely balanced to regulate gamete membrane interaction in a biphasic mode, and this biphasic regulation is executed through two different mechanisms. Mol. Reprod. Dev. 74: 1465–1472, 2007. © 2007 Wiley‐Liss, Inc.
Presumptive pre‐sertoli cells express genes involved in cell proliferation and cell signalling during a critical window in early testis differentiation
Authors: Cory Aron T. , Boyer Alexandre , Pilon Nicolas , Lussier Jacques G. , Silversides David W. 
Published: April 2007

AbstractIn mammals, the pre‐Sertoli cell of the male genital ridge is the first cell type to display sex specific differentiation and differential gene expression. The genetic cascade driving the differentiationof pre‐Sertoli cells and ultimately testis formationis beginning to be unravelled, but many questions remain. A better understanding of the transcriptome of pre‐Sertoli cells immediately after sex determination is essential in order to further understand this differentiationprocess. A mouse model expressing Red Fluorescent Protein (RFP) under the control of a hybrid mouse/pig SRY promoter (HybSRYp‐RFP) was used to purify cells from embryonic day 12.0 (e12.0) male genital ridges. To compare the transcriptomes of HybSRYp‐RFP cell populations versus age matched whole female genital ridges, RNA was extracted and used to generate molecular probes that were hybridized onto Affymetrix Mouse Genome 430 2.0 micro‐arrays. The expression of genes considered markers for pre‐Sertoli cells, including Sox9, Mis, Dhh and Fgf9 were identified within the HybSRYp‐RFP expressing cell population, while markers for germ cells (Oct4, SSEA‐1) and endothelial cells (Ntrk3) were not identified. In contrast, markers for ovarian somatic cell expression, including Fst and Bmp2, were identified as overexpressed within the ovarian cell population. In a general fashion, genes identified as 2.5‐fold over expressed in HybSRYp‐RFP expressing cells coded notably for cell signalling and extra cellular proteins. The expression of Sox10, Stc2, Fgf18, Fgf13 and Wnt6 were further characterized via whole mount in situ hybridization (WISH) on male and female genital ridges between e11.5 and e14.5. Sox10, Fgf18, Fgf13 and Stc2 gene expression was detected within the male genital ridges while Wnt6 was found diffusely within both the male and female genital ridges. These data represent the earliest comprehensive microarray expression analysis of purified presumptive pre‐Sertoli cells available to date. Mol. Reprod. Dev. 74: 1491–1504, 2007. © 2007 Wiley‐Liss, Inc.
Aging study of linseed oil resin/styrene thermosets and their composites with wood flour
Authors: Mosiewicki Mirna A , Rojas Oscar , Sibaja María R , Borrajo Julio , Aranguren Mirta I 
Published: April 2007

AbstractThe changes in the properties of new crosslinked polymers based on renewable resources and their derived composites have been monitored as a function of time; this knowledge being necessary to estimate their behavior in final applications. Rigid thermoset polymers prepared by free radical polymerization of resins obtained from linseed oil and styrene and composites reinforced with wood flour were evaluated in different environmental conditions and at different times after their preparation. The action of atmospheric oxygen on the unsaturated groups in fatty acids produces chemical changes in these polymers, which affect the properties of the cured materials. These changes were analyzed using Fourier transform infrared spectroscopy, dynamic mechanical analysis and mechanical testing. An increase in the modulus with time was observed during exposure of the samples to dry conditions, or humid environments (60% relative humidity), with or without UV irradiation. The reaction with oxygen appears to be accelerated when the materials are subjected to UV irradiation, showing a large effect on the glass transition temperature. Copyright © 2007 Society of Chemical Industry
A study of the thermodynamic properties of the system polystyrene‐ethylcyclohexane by the light scattering method
Authors: Kratochvil Jaroslav , Sedléček Blahoslav 
Published: April 2007

AbstractThe thermodynamic properties of the system polystyrene‐ethylcyclohexane (temperature 70°C) were examined between 57 and 80°C for weight fractions of the polymer 0‐0.16. Scholte's light scattering method was used for this purpose. The results are presented in the form of the temperature and concentration dependence of the interaction parameter of the Flory‐Huggins equation. The interaction function thus obtained has been tested by comparing calculated and experimental spinodals. The given system has been compared with a pseudoideal solution in order to discuss the pronounced concentration dependence of the interaction parameter and its dependence on molecular weight.
Liquid‐liquid phase separation in multicomponenent polymer systems: XV thermodynamic aspects of polymer compatibility
Authors: Koningsveld R. , Kleintjens L. A. 
Published: April 2007

AbstractCloud‐point curves in mixtures of short‐chain polymers often have irregular shapes, showing shoulders or two maxima. Limits of the thermodynamic stability as measured by Pulse Induced Critical Scattering also appear to be bimodal in such cases. A possible explanation of this phenomenon might be that the constituent molecules influence each other's chain flexibility, the more flexible chains becoming less flexible upon addition of stiffer ones, and vice versa. Such a feature is incorporated i.a. in Huggins' new theory in which orientational entropy correction terms relate the average randomness of orientation of a segment with respect to the preceding one in the chain to the surroundings of the segment.
Interaction between polymers in dilute solutions of two polymers in a single solvent measured by light scattering and the compatibility of polymers
Authors: Kratochvil Pavel , Straková Dagmar , Tuzar Zdeněk 
Published: April 2007

AbstractThe intensity of light scattered from dilute solutions of mixtures of two nonidentical polymers in a single solvent was measured. The parameter A24 characterising the thermo‐dynamic interaction of two nonidentical polymer molecules in solution was calculated for several systems polymer 2 ‐ polymer 4 ‐ solvent. For chemically strongly different polymers, A24 is independent of molecular weights of the polymers and probably also of solvent. A24 is related to the compatibility of both polymers and decreases contrary to expectation with increasing chemical difference between polymers 2 and 4.
On the second virial coefficient for solutions of polystyrene mixtures
Authors: Suzuki Hidematsu 
Published: April 2007

AbstractLight scattering measurements were carried out on several standard polystyrenes and their binary mixtures in benzene and in 2‐butanone. Their second virial coefficients, B2, were determined as a function of the polymer composition. It was revealed that for some pairs of mixtures whose components differ greatly in size, a minimum in B2 is observed, whereas a maximum is expected theoretically. The reasons for this phenomenon are discussed and interpreted in terms of the characteristics of the samples in solution and by considering the non‐negligible contribution of the attractive forces.