bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the rheological, dynamic mechanical, and tensile properties of single‐walled carbon nanotubes reinforced poly(vinyl chloride)
Authors: Abu‐Abdeen M. 
Published: November 2011

AbstractPolymer nanocomposites consisting of single‐walled carbon nanotubes (SWCNTs) and poly(vinyl chloride) were prepared by casting technique. The complex viscosity increased with increasing SWCNTs content, and it had a percolation concentration threshold equal to 0.45 wt % of SWCNTs. The storage modulus, G′, increased with increasing either SWCNTs content or frequency. A gradual decrease in the terminal zone slope of G′ for the nanocomposites with increasing SWCNTs content may be explained by the fact that the nanotube–nanotube interactions will be dominant at higher CNTs content, and lead to the formation of the interconnected or network‐like structures of SWCNTs in the polymer nanocomposites. The rheological loss factor indicates two relaxation peaks at frequencies of 0.11 and 12.8 Hz due to the interaction between SWCNTs and polymer chains and glass transition, respectively. Dynamic mechanical properties were measured for the prepared composites. The results indicate that the storage modulus changes steadily, and the tanδ peaks are less intense for high SWCNTs content. Tensile tests were measured and depicted by an increase in the elastic modulus with increasing SWCNTs content, but it decreases for all composites as the testing temperature increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of polyaniline nanostructures in micellar solutions
Authors: El‐Dib Fawzia. I. , Sayed Wafaa M. , Ahmed Sahar. M. , Elkodary Mohamed 
Published: November 2011

AbstractPolymerization of aniline nanoparticles was carried out in aqueous micellar solutions of surfactants, including anionic (sodium dodecyl sulfate), nonionic (nonyl phenol ethoxylate), and cationic (cetyltrimethyl ammonium bromide) surfactants. The size and morphology of these synthesized PANI nanoparticles strongly depended on the structure of the surfactants used in the formation of micelles, as shown by transmission electron microscopy. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction were used in the characterization of the synthesized PANI nanoparticles. The PANI nanoparticles revealed enhanced conductivity compared to conventional bulk PANI. In addition PANI–poly(methyl methacrylate) (PMMA) nanocomposites were synthesized. The results revealed that the PMMA nanoparticles retarded thermal decomposition and enhanced the conductivities compared with pristine PANI nanoparticles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
A Novel Fuzzy Approach for State Estimation of Nonlinear Hybrid Systems Using Particle Filtering Method
Authors: Salahshoor Karim , Samadi M. Foad 
Published: November 2011

AbstractReliable state estimation is challenging for nonlinear hybrid systems. Particle filtering has emerged as an appealing approach for online hybrid state estimation. Mode detection in nonlinear hybrid systems is, however, a troublesome issue for the conventional particle filter mainly due to sample impoverishment. The problem is also exacerbated when dynamics that govern healthy or faulty modes are close together. False mode detection consequently leads to erroneous continuous state estimation. This paper proposes a novel fuzzy‐based particle filter to reduce continuous state estimation errors due to failures in mode detection. It is fulfilled by considering a fuzzified contribution of each feasible mode in overall estimation. In addition, two new resampling strategies are presented to tackle the degeneracy problem. A set of simulation test studies are conducted to extract the characteristic features and evaluate the performance of the proposed algorithm compared to observation and transition‐based most likely modes tracking particle filter (OTPF) as one of the most meticulous proposed estimation algorithms. The simulation results demonstrate the superior efficiency of the algorithm in dealing with the considered potential estimation problems.
Parametric design approach for proportional multiple‐integral derivative observers in descpriptor linear systems
Authors: Wu Ai‐Guo , Duan Guang‐Ren , Hou Ming‐Zhe 
Published: November 2011

AbstractA new type of observer for descriptor linear systems, proportional multiple‐integral derivative (PMID) observers, is proposed in this paper. A parametric design approach for such observer is established. The proposed approach gives the complete parameterizations for all the observer gain matrices, realizes the elimination of impulsive behaviors, and guarantees the regularity of the observer systems. A numerical example is provided to show the design procedure and illustrate the effectiveness of the presented approach.
A sensitive method for determination of furanodiene in rat plasma using liquid chromatography/tandem mass spectrometry and its application to a pharmacokinetic study
Authors: Pei Lixia , Liu Sheng , Zheng Jin , Chen Xiuping 
Published: November 2011

ABSTRACTFuranodiene, a sesquiterpene component extracted from the essential oil of the rhizome of Curcuma wenyujin Y.H. Chen et C. Ling (Wen Ezhu), is widely used in traditional Chinese medicine. A sensitive analytical method was established and validated for furanodiene in rat plasma, which was further applied to assess the pharmacokinetics of furanodiene in rats receiving a single dose of furanodiene. Liquid chromatography tandem mass spectrometry (LC/MS/MS) in multiple reaction monitoring mode was used in the method and costundide was used as internal standard. A simple protein precipitation based on methanol was employed. The simple sample cleanup increased the throughput of the method substantially. The method was validated over the range of 1–1000 ng/mL with a correlation coefficient >0.99. The lower limit of quantification was 1 ng/mL for furanodiene in plasma. Intra‐ and inter‐day accuracies for furanodiene were 88–115 and 102–107%, and the inter‐day precision less than 14.4%. After a single oral dose of 10 mg/kg of furanodiene, the mean peak plasma concentration of furanodiene was 66.9 ± 23.4 ng/mL at 1 h, the area under the plasma concentration–time curve (AUC0–10 h) was 220 ± 47.8 h ng/mL, and the elimination half‐life was 1.53 ± 0.06 h. After an intravenous adminstration of furanodiene at a dosage of 5 mg/kg, the area under the plasma concentration–time curve was 225 ± 76.1 h⋅ng/mL, and the elimination half‐life was 2.40 ± 1.18 h. Based on this result, the oral bioavailability of furanodiene in rats at 10 mg/kg is 49.0%. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative determination of tiopronin in human plasma by LC‐MS/MS without derivatization
Authors: Yuan Bo , Zhai Nannan , Jiang Xue , Jin Yi , Liu Chunling , Li Chibing , Xu Haiyan 
Published: November 2011

ABSTRACTTiopronin (TP) is a synthetic thiol compound without chromophore. By optimizing the chromatographic conditions and sample preparation processes, an improved LC‐MS/MS analytical method without derivatization has been developed and validated to determine TP concentrations in human plasma. After reduction with 1,4‐dithiothreitol, plasma samples were deproteinized with 10% perchloric acid. The post‐treatment samples were analyzed on a C8 column interfaced with a triple quadrupole tandem mass spectrometer in negative electrospray ionization mode. Methanol–5 mmol/L ammonium acetate (20:80, v/v) was used as the isocratic mobile phase. The assay was linear over the concentration range of 40.0–5000 ng/mL. The intra‐ and inter‐day precisions were within 12.9% in terms of relative standard deviation and the accuracy within 5.6% in terms of relative error. This simple and sensitive LC‐MS/MS method with short analytical time (3.5 min each sample) was successfully applied to the pharmacokinetic study of TP in healthy Chinese male volunteers after an oral dose of 300 mg TP. Copyright © 2011 John Wiley & Sons, Ltd.
Photoactivatable Caged Cyclic RGD Peptide for Triggering Integrin Binding and Cell Adhesion to Surfaces
Authors: Wirkner Melanie , Weis Simone , San Miguel Verónica , Álvarez Marta , Gropeanu Radu A. , Salierno Marcelo , Sartoris Anne , Unger Ronald E. , Kirkpatrick C. James , del Campo Aránzazu 
Published: November 2011

AbstractWe report the synthesis and properties of a photoactivatable caged RGD peptide and its application for phototriggering integrin‐ and cell‐binding to surfaces. We analysed in detail 1) the differences in the integrin‐binding affinity of the caged and uncaged forms by quartz crystal microbalance (QCM) studies, 2) the efficiency and yield of the photolytic uncaging reaction, 3) the biocompatibility of the photolysis by‐products and irradiation conditions, 4) the possibility of site, temporal and density control of integrin‐binding and therefore human cell attachment, and 5) the possibility of in situ generation of cell patterns and cell gradients by controlling the UV exposure. These studies provide a clear picture of the potential and limitations of caged RGD for integrin‐mediated cell adhesion and demonstrate the application of this approach to the control and study of cell interactions and responses.
Influence of Sugar Ring Conformation on the Transportability of Nucleosides by Human Nucleoside Transporters
Authors: Damaraju Vijaya L. , Mowles Delores , Smith Kyla M. , Yao Sylvia Y. M. , Young James D. , Marquez Victor E. , Cass Carol E. 
Published: November 2011

AbstractThe conformational preference of human nucleoside transporters (hNTs) with respect to sugar ring was examined using conformationally fixed purine and pyrimidine nucleosides built on a bicyclo[3.1.0]hexane template. These fixed‐conformation nucleosides, methanocarba‐deoxyadenosine or methanocarba‐deoxycytidine in North (C3′‐endo, N‐MCdA and N‐MCdC) or South (C2′‐endo, S‐MCdA and S‐MCdC) conformations, were used to study inhibition of equilibrative (hENT1–4) and concentrative (hCNT1–3) nucleoside transport by individual recombinant hNTs produced in Saccharomyces cerevisiae cells or Xenopus laevis oocytes. Our results indicated that nucleosides in the North conformation were potent inhibitors of transport mediated by hCNTs whereas South nucleosides were inhibitors of hENTs, thus showing differences in the interaction with the hNTs. In summary, hCNTs exhibited strong preferences for North nucleosides whereas hENTs exhibited slight preferences for South nucleosides, demonstrating for the first time different conformational preferences among members of the two families of hNTs.
A non‐linear homogeneous model for bone‐like materials under compressive load
Authors: Mengoni M. , Voide R. , de Bien C. , Freichels H. , Jérôme C. , Léonard A. , Toye D. , Müller R. , van Lenthe G. H. , Ponthot J. P. 
Published: November 2011

SUMMARYFinite element (FE) models accurately compute the mechanical response of bone and bone‐like materials when the models include their detailed microstructure. In order to simulate non‐linear behavior, which currently is only feasible at the expense of extremely high computational costs, coarser models can be used if the local morphology has been linked to the apparent mechanical behavior. The aim of this paper is to implement and validate such a constitutive law. This law is able to capture the non‐linear structural behavior of bone‐like materials through the use of fabric tensors. It also allows for irreversible strains using an elastoplastic material model incorporating hardening. These features are expressed in a constitutive law based on the anisotropic continuum damage theory coupled with isotropic elastoplasticity in a finite strain framework. This material model was implemented into metafor (LTAS‐MNNL, University of Liège, Belgium), a non‐linear FE software. The implementation was validated against experimental data of cylindrical samples subjected to compression. Three materials with bone‐like microstructure were tested: aluminum foams of variable density (ERG, Oakland, CA, USA), polylactic acid foam (CERM, University of Liège, Liège, Belgium), and cancellous bone tissue of a deer antler (Faculty of Veterinary Medicine, University of Liège, Liège, Belgium). Copyright © 2011 John Wiley & Sons, Ltd.
Changes in expression profiles of antioxidant enzymes in diabetic rat kidneys
Authors: Sadi Gökhan , Eryilmaz Nihan , Tütüncüoğlu Egemen , Cingir Şahika , Güray Tülin 
Published: November 2011

AbstractBackgroundIn diabetes mellitus, increased formation of reactive oxygen species due to high level of glucose in both blood plasma and tissues creates oxidative stress and damages the tissues. Antioxidants together with the antioxidant enzymes are very important in order to protect the cells against oxidative damage.MethodsDifferential expressions of both mRNA and proteins of major antioxidant enzymes in streptozotocin‐induced diabetic rat kidneys were measured with the help of real‐time polymerase chain reaction and western blot analysis, respectively. Furthermore, effects of two strong antioxidants α‐lipoic acid, vitamin C and their combination on the regulation of both expressions and the activities of antioxidant enzymes were also studied.ResultsIn diabetic rat kidney tissue, both catalase and glutathione peroxidase activities were reduced (although mRNA expression for both was greatly increased) when compared with controls. No significant change was observed in superoxide dismutase (SOD) activity. Alpha‐lipoic acid increased catalase activity towards the control values. Combined administration of alpha‐lipoic acid and vitamin C increased the activities of both catalase and SOD, demonstrating a posttranslational effect. Glutathione concentrations were decreased in diabetic kidney; alpha‐lipoic acid treatment partially restored the glutathione levels.ConclusionsAll data showed the importance of post‐transcriptional and translational regulation of the antioxidant enzyme activities against oxidative stress that is associated with diabetes. Copyright © 2011 John Wiley & Sons, Ltd.
MCS9.7 enhancer activity is highly, but not completely, associated with expression of Irf6 and p63
Authors: Fakhouri Walid D. , Rhea Lindsey , Du Tianli , Sweezer Eileen , Morrison Harris , Fitzpatrick David , Yang Baoli , Dunnwald Martine , Schutte Brian C. 
Published: November 2011

AbstractBackground: DNA variation in Interferon Regulatory Factor 6 (IRF6) contributes risk for orofacial clefting, including a common DNA variant rs642961. This DNA variant is located in a multi‐species conserved sequence that is 9.7 kb upstream from the IRF6 transcriptional start site (MCS9.7). The MCS9.7 element was shown to possess enhancer activity that mimicked the expression of endogenous Irf6 at embryonic day 11.5 in transient transgenic embryos, and also contains a p63 binding site that transactivates IRF6 expression. To analyze whether the MCS9.7 enhancer is sufficient to drive IRF6 expression, we generated stable transgenic murine lines that carry a MCS9.7‐lacZ transgene. We hypothesized that MCS9.7 was sufficient to recapitulate the endogenous expression of Irf6 at other time‐points during embryonic development. Results: We observed that MCS9.7 activity recapitulated endogenous Irf6 expression in most tissues, but not in the medial edge epithelium (MEE) at E14.5, when Irf6 expression was high during secondary palatal fusion. Also, while MCS9.7 activity and Irf6 expression were associated with p63 expression, we observed MCS9.7 activity and Irf6 expression in periderm, although p63 was absent. Conclusion: These data suggest that MCS9.7 enhancer activity is not sufficient to recapitulate IRF6 expression, and that p63 expression is not always necessary nor sufficient for transactivation of IRF6. Developmental Dynamics 241:340–349, 2012. © 2011 Wiley Periodicals, Inc.
An in vivo map of bone morphogenetic protein 2 post‐transcriptional repression in the heart
Authors: Kruithof Boudewijn P. T. , Xu Junwang , Fritz David T. , Cabral Carolina S. , Gaussin Vinciane , Rogers Melissa B. 
Published: November 2011

AbstractCoronary artery sections from day 13.5 transgenic mouse pups were stained by immuno‐fluorescence for a‐smooth muscle actin (red) and counterstained with DAPI (green) to mark nuclei. The blue, β‐galactosidase‐positive cells express a Bmp2‐driven lacZ reporter gene that lacks a post‐transcriptional repressor conserved from mammals to fishes. See Kruithof et al., An In Vivo Map of Bone Morphogenetic Protein 2 Post‐transcriptional Repression in the Heart.
Controllable Synthesis of Single‐Crystalline Fe3O4 Nanorice by a One‐Pot, Surfactant‐Assisted Hydrothermal Method and Its Properties
Authors: Rajendran Ramesh , Muralidharan Rajalakshmi , Santhana Gopalakrishnan Ramya , Chellamuthu Muthamizhchelvan , Ponnusamy Suruttaiya U. , Manikandan Elayaperumal 
Published: November 2011

AbstractSingle‐crystalline Fe3O4 nanorice has been prepared by a simple one‐pot, surfactant‐assisted hydrothermal method using dodecyltrimethylammonium bromide (DTAB) as a surfactant. X‐ray powder diffraction, field emission scanning electron microscopy (FESEM), TEM, high‐resolution (HR)TEM, micro‐Raman spectroscopy and magnetic measurements have been employed to study the properties of the product. The importance of NaAc and ethylene glycol in the formation of the pure magnetite phase has been established. The as‐synthesized products have a regular rice‐like shape with an average diameter of 150 nm and length of 500 nm and are monodisperse. Shape evolution from cauliflower‐ to rice‐like morphology has been achieved by controlling the DTAB concentration. A possible formation mechanism for the Fe3O4 nanorice is explored. Furthermore, the product showed ferromagnetic properties at room temperature.
The Shortest Strategy for Generating Phosphonate Prodrugs by Olefin Cross‐Metathesis – Application to Acyclonucleoside Phosphonates
Authors: Pradère Ugo , Clavier Hervé , Roy Vincent , Nolan Steven P. , Agrofoglio Luigi A. 
Published: November 2011

AbstractA short synthetic route to phosphonate prodrugs by olefin cross‐metathesis, which uses either (acyloxymethyl) or (hexadecyloxypropyl) allylphosphonate building blocks is described. A study of eight ruthenium catalysts including the Ru–indenylidene catalyst, which bears the N‐heterocyclic carbene 1,3‐bis(2,6‐diisopropylphenyl)‐4,5‐dihydroimidazol‐2‐ylidene, was undertaken. This method was applied to the synthesis of acyclonucleoside phosphonate prodrugs. This strategy is appealing for further uses in pharmaceutical and medicinal research.
Synthesis of Chiral Benzoxa(thia)zepine and Pyridoxazepine Derivatives Using Palladium‐Catalyzed Intramolecular Aryl Amination Reaction
Authors: Das Adhikary Nirmal , Chattopadhyay Partha 
Published: November 2011

AbstractA palladium‐catalyzed method employing different bulky biaryl phosphanes as ligands has been developed for the intramolecular amination of aryl bromides and iodides. A variety of aryl halide substrates have been aminated through the intramolecular pathway in good yield using different sugar‐derived amines to give furo‐benzoxa(thia)zepine and pyridoxazepine derivatives. The method is capable of furnishing chiral, enantiopure benzoxa(thia)zepines and pyridoxazepines of significant biological importance.
1,3‐Benzyl Migration in Iminium Ions: Evidence for a Fast Free‐Radical Chain Reaction
Authors: Blank Nancy , Straub Bernd F. , Opatz Till 
Published: November 2011

AbstractThe “exocyclic” 1,3‐benzyl shift observed in iminium salts derived from 1‐benzyl‐1,2,3,4‐tetrahydroisoquinolines is related to the “endocyclic” Knabe rearrangement. A crossover experiment, isotopic labelling, the study of initiators and inhibitors as well as DFT calculations of gas‐phase model structures provide evidence for a free‐radical pathway under kinetic entropy control that is not affected by “slow” radical traps.
Asymmetric Methoxyselenenylations with Chiral Selenium Electrophiles
Authors: Zhao Liwei , Li Zhong , Wirth Thomas 
Published: November 2011

AbstractVery simple, chiral, non‐racemic diselenides were prepared and their corresponding selenium electrophiles were used for the stereoselective functionalization of alkenes. The influence of different alkenes on the outcome of the selenenylation reaction was investigated.
Chute channel dynamics in large, sand‐bed meandering rivers
Authors: Grenfell Michael , Aalto Rolf , Nicholas Andrew 
Published: November 2011

ABSTRACTMeander bends of many large, sand‐bed meandering rivers are partitioned by chute channels that convey permanent flow, and co‐exist with the mainstem for decades. As a first step toward understanding the dynamics and morphodynamic implications of these ‘bifurcate meander bends’, this study applied binary logistic regression analysis to determine whether it is possible to predict chute initiation based on attributes of meander bend character and dynamics. Regression models developed for the Strickland River, Papua New Guinea, the lower Paraguay River, Paraguay/Argentina, and the Beni River, Bolivia, revealed that the probability of chute initiation at a meander bend is a function of the bend extension rate (the rate at which a bend elongates in a direction perpendicular to the valley axis trend). Image analyses of all rivers and field observations from the Strickland suggest that the majority of chute channels form during scroll–slough development. Rapid extension is shown to favour chute initiation by breaking the continuity of point bar deposition and vegetation encroachment at the inner bank, resulting in widely‐spaced scrolls with intervening sloughs that are positively aligned with primary over‐bar flow. The rivers plot in order of increasing chute activity on an empirical meandering‐braided pattern continuum defined by potential specific stream power (ωpv) and bedload calibre (D50). Increasing stream power is considered to result in higher bend extension rates, with implications for chute initiation. In addition, chute stability is shown to depend on river sediment load relative to flow discharge (Qs/Q), such that while the Beni may plot in the region of highly braided rivers by virtue of a high potential specific stream power, the formation of stable chute channels is suppressed by the high sediment load. This tendency is consistent with previous experimental studies, and results in a planform that is transitional between single‐thread meandering and braided. Copyright © 2011 John Wiley & Sons, Ltd.
N‐cadherin and M‐cadherin are sequentially expressed in myoblast populations contributing to the first and second waves of myogenesis in the trout (Oncorhynchus mykiss)
Authors: Rescan Pierre‐Yves , Ralliere Cécile , Lebret Veronique 
Published: November 2011

AbstractThe objective of this study was to investigate the expression of two promyogenic cell surface adhesion receptors, N‐ and M‐cadherin, in developing trout (Oncorhynchus mykiss) somite, taking account of the recent identification of a dermomyotome‐like epithelium in teleosts. In situ hybridization showed that N‐cadherin was expressed throughout the paraxial mesoderm and nascent somite. As the somite matured, N‐cadherin expression disappeared ventrally from the sclerotome, and then mediolaterally from the differentiating slow and fast muscle cells of the embryonic myotome, to become finally restricted to the undifferentiated myogenic precursors forming the dermomyotome‐like epithelium that surrounds the embryonic myotome. By contrast, M‐cadherin, which was transcribed in the differentiating embryonic myotome, was never expressed in the dermomyotome‐like epithelium. In late‐stage trout embryos, M‐cadherin transcript was only detected at the periphery of the expanding myotome, where muscle cells stemming from the N‐cadherin positive dermomyotome‐like epithelium differentiate. Collectively, our results support the view that, in trout embryo, N‐cadherin is associated with muscle cell immaturity while M‐cadherin is associated with muscle cell maturation and differentiation and this during the two successive phases of myogenesis. J. Exp. Zool. (Mol. Dev. Evol.) 318:71–77,
2012. © 2011 Wiley Periodicals, Inc.