bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hedgehog/GLI1 regulates IGF dependent malignant behaviors in glioma stem cells
Authors: Hsieh Antony , Ellsworth Ron , Hsieh David 
Published: September 2010

AbstractA population of tumorigenic, chemoresistant, and radioresistant cancer stem cells is postulated to contribute to the aggressive and fatal clinical course of glioblastomas. Activation of the Hedgehog (HH) pathway and increased expression of its downstream effector GLI1 are driving factors of glioma tumorigenicity and glioma stem cell (GSC) biology. In this study, we describe a dependence of insulin‐like growth factor (IGF) signaling on active HH/GLI1 in GSCs. Insulin receptor substrate 1 (IRS1) was identified as a target of the GLI1 transcription factor and inhibition of GLI1 was sufficient to obstruct IRS1 protein expression and IGF‐I induced mitogen‐activated protein kinase (MAPK) activation. Suppression of GLI1 activity decreased the responsiveness of GSCs to IGF‐I stimulation and constrained IGF‐I dependent GSC proliferation, clonogenicity, invasion, and angiogenesis. In addition, blockade of the HH/GLI1 and IGF pathways countered the intrinsic and acquired resistance of GSCs to temozolomide. These results provide further insight into the oncogenic mechanisms of the HH pathway in glioblastoma and demonstrate a cooperative signaling axis between the HH/GLI1 and IGF pathways to propagate malignant GSC phenotypes. J. Cell. Physiol. 226: 1118–1127, 2011. © 2010 Wiley‐Liss, Inc.
Distribution and classification of aggrecan‐based extracellular matrix in the thalamus of the rat
Authors: Gáti Georgina , Morawski Markus , Lendvai Dávid , Jäger Carsten , Négyessy László , Arendt Thomas , Alpár Alán 
Published: September 2010

AbstractExtracellular matrix molecules take part in functional isolation and stabilization of neuronal compartments but form a vivid interface between neuronal elements at the same time. Previous studies have shown that the accumulation of extracellular matrix, especially its typical phenotypic form, termed perineuronal nets, correlates not only with the functional properties of the single neuron but also with the functional properties of the whole brain area. In contrast to recent advances in investigating neocortex, the present study mapped the occurrence and phenotypic appearance of aggrecan‐based matrix accumulation throughout the rat thalamus. Results showed that divisions of thalamus that relay information to cortical fields known rather for their plastic properties exibit a poor matrix immunoreactivity, whereas matrix accumulation is more enhanced in nuclei connected to primary cortical regions. In addition to perineuronal nets, extracellular matrix condensed in another peculiar form, in 2–5‐μm, large, round or oval structures, as described by Brückner et al. ([ 2008] Neuroscience 151:489–504) as axonal coats (ACs). Multiple labelling experiments showed that specific excitatory afferents were not ensheathed with these structures. At the same time, inhibitory endings were occasionally enwrapped in ACs. Electron microscopic analysis showed that aggrecan‐immunoreactive profiles were present mostly around inhibitory terminals but also in all neuronal compartments. We suggest that aggrecan‐based extracellular matrix is formed by both pre‐ and postsynaptic elements and is preferrably associated with inhibitory terminals in the extracellular space. © 2010 Wiley‐Liss, Inc.
Cerebrolysin enhances neurogenesis in the ischemic brain and improves functional outcome after stroke
Authors: Zhang Chunling , Chopp Michael , Cui Yisheng , Wang Lei , Zhang Ruilan , Zhang Li , Lu Mei , Szalad Alexandra , Doppler Edith , Hitzl Monika , Zhang Zheng Gang 
Published: September 2010

AbstractCerebrolysin is a peptide preparation mimicking the action of neurotrophic factors and has beneficial effects on neurodegenerative diseases and stroke. The present study investigated the effect of Cerebrolysin on neurogenesis in a rat model of embolic middle cerebral artery occlusion (MCAo). Treatment with Cerebrolysin at doses of 2.5 and 5 ml/kg significantly increased the number of bromodeoxyuridine‐positive (BrdU+) subventricular zone (SVZ) neural progenitor cells and doublecortin (DCX) immunoreactivity (migrating neuroblasts) in the ipsilateral SVZ and striatal ischemic boundary 28 days after stroke when the treatment was initiated 24 hr after stroke. The treatment also reduced TUNEL+ cells by ∼50% in the ischemic boundary. However, treatment with Cerebrolysin at a dose of 2.5 ml/kg initiated at 24 and 48 hr did not significantly reduce infarct volume but substantially improved neurological outcomes measured by an array of behavioral tests 21 and 28 days after stroke. Incubation of SVZ neural progenitor cells from ischemic rats with Cerebrolysin dose dependently augmented BrdU+ cells and increased the number of Tuj1+ cells (a marker of immature neurons). Blockage of the PI3K/Akt pathway abolished Cerebrolysin‐increased BrdU+ cells. Moreover, Cerebrolysin treatment promoted neural progenitor cell migration. Collectively, these data indicate that Cerebrolysin treatment when initiated 24 and 48 hr after stroke enhances neurogenesis in the ischemic brain and improves functional outcome and that Cerebrolysin‐augmented proliferation, differentiation, and migration of adult SVZ neural progenitor cells contribute to Cerebrolysin‐induced neurogenesis, which may be related to improvement of neurological outcome. The PI3K/Akt pathway mediates Cerebrolysin‐induced progenitor cell proliferation. © 2010 Wiley‐Liss, Inc.
Effect of posterior tibial slope on knee biomechanics during functional activity
Authors: Shelburne Kevin B. , Kim Hyung‐Joo , Sterett William I. , Pandy Marcus G. 
Published: September 2010

AbstractTreatment of medial compartment knee osteoarthritis with high tibial osteotomy can produce an unintended change in the slope of the tibial plateau in the sagittal plane. The effect of changing posterior tibial slope (PTS) on cruciate ligament forces has not been quantified for knee loading in activities of daily living. The purpose of this study was to determine how changes in PTS affect tibial shear force, anterior tibial translation (ATT), and knee‐ligament loading during daily physical activity. We hypothesized that tibial shear force, ATT, and ACL force all increase as PTS increases. A previously validated computer model was used to calculate ATT, tibial shear force, and cruciate‐ligament forces for the normal knee during three common load‐bearing tasks: standing, squatting, and walking. The model calculations were repeated with PTS altered in 1° increments up to a maximum change in tibial slope of 10°. Tibial shear force and ATT increased as PTS was increased. For standing and walking, ACL force increased as tibial slope was increased; for squatting, PCL force decreased as tibial slope was increased. The effect of changing PTS on ACL force was greatest for walking. The true effect of changing tibial slope on knee‐joint biomechanics may only be evident under physiologic loading conditions which include muscle forces. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:223–231, 2011
Multifunctional Hybrid Three‐dimensionally Woven Scaffolds for Cartilage Tissue Engineering
Authors: Moutos Franklin T. , Estes Bradley T. , Guilak Farshid 
Published: September 2010

AbstractThe successful replacement of large‐scale cartilage defects or osteoarthritic lesions using tissue‐engineering approaches will likely require composite biomaterial scaffolds that have biomimetic mechanical properties and can provide cell‐instructive cues to control the growth and differentiation of embedded stem or progenitor cells. This study describes a novel method of constructing multifunctional scaffolds for cartilage tissue engineering that can provide both mechanical support and biological stimulation to seeded progenitor cells. 3‐D woven PCL scaffolds were infiltrated with a slurry of homogenized CDM of porcine origin, seeded with human ASCs, and cultured for up to 42 d under standard growth conditions. These constructs were compared to scaffolds derived solely from CDM as well as 3‐D woven PCL fabric without CDM. While all scaffolds promoted a chondrogenic phenotype of the ASCs, CDM scaffolds showed low compressive and shear moduli and contracted significantly during culture. Fiber‐reinforced CDM scaffolds and 3‐D woven PCL scaffolds maintained their mechanical properties throughout the culture period, while supporting the accumulation of a cartilaginous extracellular matrix. These findings show that fiber‐reinforced hybrid scaffolds can be produced with biomimetic mechanical properties as well as the ability to promote ASC differentiation and chondrogenesis in vitro.
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Tailored Additives to Improve the Electret Performance of Polycarbonates
Authors: Erhard Dominik P. , Lovera Deliani , Jenninger Werner , Wagner Joachim , Altstädt Volker , Schmidt Hans‐Werner 
Published: September 2010

AbstractAn electret is a dielectric material exhibiting a quasi‐permanent electric charge. The aim of this work is to give access to PC electret materials with a distinctly improved electret performance. In this context, the charge storage capabilities of corona charged films of several PC grades were investigated by isothermal potential decay measurements at 90 °C. The most promising PC grade was further improved by a new class of bisimide additives. The best additive at the most efficient concentration in combination with a physical aging step yielded excellent PC electrets maintaining almost their complete applied charge even at 90 °C.
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On Monotone Almost (P, μ) ‐ u. d. Mod 1 Sequence
Authors: Goto Kazuo 
Published: September 2010

AbstractUsing the result of almost u.d. mod 1 and G. Hoheisel [6] and Emdös's result, Akiyama [1] gave a different proof of the Erdös and Turán result [4], i.e., Δ2 log pn changes its sign infinitely many times, where pn is the n‐th prime number and Δ2 f(n) = Δ(Δf(n)), Δf(n) = f(n + 1)‐f(n).In this paper, we show the neceasary condition for monotone almost uniform distribution mod 1. We give Fejér's type theorem for almost uniform distribution mod 1 and give a similar result of Niederreiter [8]. Also we obtain the converse of its result with some conditions. As an application, we give a simple proof [1] of Erdös and Turán's result using Erdös's result [cf. 3, 9, 10, 11, and 21. Also we obtain the condition of P(n) that Δ2 log P(n) changes its sign infinitely many times.
Verification Algorithms for Generalized Singular Values
Authors: Alefeld Götz , Hoffmann Rolf , Mayer Günter , Wildenhain G. 
Published: September 2010

AbstractBy means of interval arithmetic tools we present new algorithms for verifying and enclosing generalized singular values and corresponding vectors for a matrix pair (A, B) ε IRp×n × IRq×n. To this end, we state and prove a fundamental theorem in interval analysis which shows a way how enclosures can be constructed if approximations are known. Furthermore, we perform a careful comparison of the new method with those introduced in [11].
orsions for Manifolds with Boundary and Glueing Formulas
Authors: Burghelea Dan , Friedlander Leonid , Kappeler Thomas 
Published: September 2010

AbstractWe extend the definition of analytic and Reidemeister torsion for closed compact iemannian manifolds, to compact Riemannian manifolds with boundary (M, δ M), given a parallel at bundle F of A‐Hilbert modules of finite type and a decomposition of the boundary δM = ‐M ⊔ δ+M into disjoint components. When F is induced from the universal covering of M, and the fundamental group of M is infinite (cf. [BFKM]), these torsions are known as the L2‐analytic resp. 2‐Reidemeister torsions. If the system (M, δ‐M, δ+M, F) is of determinant class we compute he quotient of the analytic and the Reidemeister torsion and prove gluing formulas for both of hem. In particular we answer positively Conjecture 7.6 in [LL]. If F is induced from a Γ‐principal overing where Γ is a residually finite group, we derive from work of Lück (cf. [L3]), that the system (M, δ‐M, δ+M, F) is of determinant class (cf. Theorem 5.1 in Appendix A).
On the Jacobian Varieties of Picard Curves: Explicit Addition Law and Algebraic Structure
Authors: Sarlabous Jorge Estrada , Barreiro Ernesto Reinaldo , Barceló Jorge Alejandro Pieiro 
Published: September 2010

AbstractIn this paper a system of coordinates for the effective divisors on the Jacobian Variety of a Picard curve is presented. These coordinates possess a nice geometric interpretation and provide us with an unifying environment to obtain an explicit structure of algebraic variety on the Jacobian as well as an efficient algorithm for the addition of divisors.
Discrete Dipole Moments and Enhanced Electro‐Rheological Properties of Dumbbell‐Shaped, Non‐Spherical Particles
Authors: Shin Kyomin , Lee Sunmi , Kim Jin‐Joo , Suh Kyung‐Do 
Published: September 2010

AbstractIn this study, uniform dumbbell‐shaped non‐spherical particles are produced by seeded polymerization, and the electro‐rheological (ER) properties are compared to those of spherical‐shaped particles after surface coating with functionalized multiwall carbon nanotubes (f‐MWCNTs). The non‐spherical particles formed linear chains under an applied electric field. The yield stress of the non‐spherical particles is five‐times as high as that of the spherical particles. The enhanced ER properties of the dumbbell‐shaped non‐spherical particles are attributed to the discrete dipole moments, which are found to depend on the morphology.
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A Practical Approach to the Development of Inkjet Printable Functional Ionogels—Bendable, Foldable, Transparent, and Conductive Electrode Materials
Authors: Delaney Joseph T. , Liberski Albert R. , Perelaer Jolke , Schubert Ulrich S. 
Published: September 2010

AbstractIonic liquid gels, or ionogels, are semi‐conductive, flexible materials, offering a host of tunable physical properties, gaining an increasing level of scientific interest. One of the challenges of this emerging category of materials is that the structure–process–property relationships are still empirically driven. In this study, a simple, practical approach is laid out to prepare standardized libraries of these materials, for the purpose of selecting transparent, flexible conductive formulations that can be dispensed using inkjet printing. The net result of this was the optimization of a PEG‐DMA ionogel formulation exhibiting an optical transparency that was greater than 94% from near‐UV to near‐IR from a 150 µm thick films, and a resistivity of 12.4 Ω · m.
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Mathematical Modeling of MWD and CBD in Polymerizations with Macromonomer Reincorporation and Chain Running
Authors: Ferreira Luis Carlos , Nele Márcio , Costa Marcos A.S. , Pinto José Carlos 
Published: September 2010

AbstractA model is proposed for the computation of MWD and CBD when the simultaneous formation of LCB and SCB is possible. LCBs are produced through incorporation of unsaturated polymer chains. SCBs are produced through chain running as a series of spontaneous chain transfer and reinsertion steps. The model was solved numerically with the help of orthogonal adaptive collocation techniques. It is shown that ten collocation points are sufficient to provide accurate numerical solutions for the evolution of MWDs and CBDs. The model can be used successfully to represent experimental data available for ethylene polymerizations performed with nickel catalysts and butadiene polymerizations performed with neodymium catalysts.
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Boundary element methods for Dirichlet boundary control problems
Authors: Of Günther , Phan Thanh Xuan , Steinbach Olaf 
Published: September 2010

AbstractIn this article we discuss the application of boundary element methods for the solution of Dirichlet boundary control problems subject to the Poisson equation with box constraints on the control. The solutions of both the primal and adjoint boundary value problems are given by representation formulae, where the state enters the adjoint problem as volume density. To avoid the related volume potential we apply integration by parts to the representation formula of the adjoint problem. This results in a system of boundary integral equations which is related to the Bi‐Laplacian. For the related Dirichlet to Neumann map, we analyse two different boundary integral representations. The first one is based on the use of single and double layer potentials only, but requires some additional assumptions to ensure stability of the discrete scheme. As a second approach, we consider the symmetric formulation which is based on the use of the Calderon projector and which is stable for standard boundary element discretizations. For both methods, we prove stability and related error estimates which are confirmed by numerical examples. Copyright © 2010 John Wiley & Sons, Ltd.
Advanced Monitoring and Control of Multi‐monomer System in Emulsion Polymerization
Authors: Gomes Vincent G. 
Published: September 2010

AbstractA control framework was developed for real‐time implementation of optimal control of emulsion polymerization with multiple monomers by integrating model‐based algorithms with software engines. The developed system was applied for controlling conversion, particle size, molar mass, and polymer composition using model predictive control (MPC) based on mechanistic models for emulsion polymerization. The control formulation was extended to account for existing process constraints on the input, input moves, and solids content. On experimental testing, the developed control scheme was found to achieve the desired objectives without violating the process constraints and showed good robustness in rejecting disturbances. Improvements in the process operation and polymer property control were noted on implementing the developed multi‐variable MPC for molar mass and product composition. The system facilitated efficient control of fundamental polymer attributes with semi‐batch operation.
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Synthesis and electromagnetic interference shielding properties of iron oxide/polypyrrole nanocomposites
Authors: Azadmanjiri J. , Hojati‐Talemi P. , Simon G.P. , Suzuki K. , Selomulya C. 
Published: September 2010

AbstractMagnetic nanocomposites were prepared by an in situ oxidative polymerization method to encapsulate different loadings of iron oxide nanoparticles (MNP) by a conductive polymer, polypyrrole (PPy), and were blended into an epoxy resin matrix. The morphology, DC conductivity, magnetic, and electromagnetic interference (EMI) shielding behaviors of samples dispersed in the resin were characterized, the latter by use of a vector network analyzer in a frequency range of 0.1–18 GHz. Nanocomposites based on the use of MNP/PPy composite nanoparticles in which the magnetic and conducting phases coexist in intimate contact showed a marked increase in the absorption 10.10 dB at the maximum frequency limit (17–18 GHz) of the instrument, in comparison with the absorption bands for PPy particles only (7.5 dB) or MNP only (2.6 dB) or physical blends of MNP and PPy particles (3.6 dB) in the resin. The mechanism of this enhancement is discussed based on electromagnetic theory. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Electrically conducting polypropylene/polyaniline‐grafted‐short glass fiber composites: Microstructure and dynamic mechanical analysis
Authors: Valerio‐Cárdenas Cintya , Romo‐Uribe Angel , Cruz‐Silva Rodolfo 
Published: September 2010

AbstractThe thermal properties of isotactic polypropylene (iPP) reinforced with polyaniline‐grafted‐short glass fibers (PAn‐g‐SGF) at 10, 20, and 30 wt% concentration and iPP blended with 5 wt% PP‐grafted‐maleic anhydride (PP‐gMA) and 30 wt% of PAn‐g‐SGF were investigated. iPP crystallizes into a spherulitic morphology, the microfiller promoted larger spherulite size and higher dynamic modulus, but the overall degree of crystallinity decreased as the concentration of PAn‐g‐SGF increased. The melting temperature, Tm, was not influenced by the microfiller. However, the crystallization temperature, Tc, as determined by DMA, first decreased reaching a minimum at ca. 20 wt%, and then increased, in contrast with Tc determined by DSC, it increased as concentration increased. The initial reduction in Tc observed by DMA seems to be associated with the crystallites growing from the microfiller into the matrix, the overall molecular dynamics then being less affected. On the other hand, increase in Tc above 20 wt% concentration suggests that the percolation threshold could be responsible for these results. Addition of the maleic anhydride copolymer produced higher shear modulus, transition temperatures, and activation energy, suggesting higher interaction between microfiller and polymer matrix. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Preparation of thermoplastic elastomer nanocomposites based on polyamide‐6/polyepichlorohydrin‐co‐ethylene oxide
Authors: Naderi Ghasem , Razavi‐Nouri Mohammad , Taghizadeh Ehsan , Lafleur Pierre G. , Dubois Charles 
Published: September 2010

AbstractThis work is aimed at determining the effect of nanoclay and polyepichlorohydrin‐co‐ethylene oxide (ECO) content on the microstructure and mechanical properties of PA6/ECO thermoplastic elastomers (TPEs). TPE nanocomposites were prepared in a laboratory mixer using polyamide 6 (PA6), ECO, and an organoclay by a two‐step melt mixing process. First, the PA6 was melt blended with Cloisite 30B and then mixed by ECO rubber. X‐ray diffraction results and transmission electron microscopy image showed that the nanoclay platelets were nearly exfoliated in both the phases. The SEM photomicrograph of PA6 with ECO showed that the elastomer particles are dispersed throughout the polyamide matrix and the size of rubber particles is less than 3 μm. Introduction of organoclay in the PA6 matrix increased the size of dispersed rubber particles in comparison with the unfilled but otherwise similar blends. The nanoscale dimension of the dispersed clay results in an improvement of the tensile modulus of the nanocomposites. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Synthesis of polymers containing regularly distributed tetrathia‐[7]‐elicene units along the backbone
Authors: Fenili Fabio , Rigamonti Clara , Bossi Alberto , Ferruti Paolo , Manfredi Amedea , Maiorana Stefano , Baldoli Clara , Cauteruccio Silvia , Licandro Emanuela , Ranucci Elisabetta 
Published: September 2010

AbstractA tetrathia‐[7]‐helicene bearing in the 2 and 13 positions cyanovinyl groups was used as comonomer in the Michael‐type polyaddition reaction with N,N′‐bis(β‐mercaptoethyl)piperazine. This led to a new polymer bearing tetrathia‐[7]‐helicene units regularly distributed along the polymer backbone, which may be regarded as the first example of a new family of potentially useful nonlinear optical materials. All products were structurally characterized by 1H and 13C NMR spectroscopy. Differential scanning calorimetry characterizations revealed the presence, in both monomeric and polymeric helicenes, of glass‐transition like temperatures, associated to some conformational variation of the helicene units. The optical properties, the film formation and the morphology of the polymer‐containing tetratia‐[7]‐helicenes were also investigated. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010