bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physicochemical and structural effects of electrolyte‐induced delamination on polyethylene teraphthalate‐coated steel plates
Authors: Zumelzu E. , Ortega C. , Rull F. , Cabezas C. 
Published: August 2011

AbstractThis research evaluated the in situ physicochemical changes and alterations occurring in an electrolytic chromium coated steel (ECCS), surface protected by polyethylene teraphthalate (PET) copolymer, after inducing a fracture on the coating in an acid acetic‐acetate medium. The delamination was characterized in the front of the failure by means of anodic and cathodic electrochemical mechanisms, and the resistance and degradation of the metal‐polymer composite's substrates were analyzed by means of Raman vibrational spectroscopy. The application of an electrochemical cell to generate in situ delamination, simulating the formation of pores or artificial defects, provided information on the activity inside the substrates of the PET‐coated ECCS composite as a result of the effect of the acetic acid. The anodic delamination mechanism is based on the diffusion of the electrolyte through the metal‐polymer interface and the pre‐existence of pores on the polymer layer. The cathodic delamination mechanism is based on the mechanical action of the gaseous hydrogen as a result of the reduction of H+. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Fabrication and characterization of silica/polypyrrole nanocomposites using silica sulfuric acid as templates
Authors: Wang Wenqin , Li Wenli , Chai Zhangling , Zhang Ruifeng 
Published: August 2011

AbstractThe sunflower‐like silica core‐polypyrrole (PPy) shell nanocomposites were prepared by using silica sulfuric acid as templates. The silica sulfuric acid was obtained by treating directly the silica nanoparticles with chlorosulfonic acid. The sulfonic groups (SO3H) on the surface of silica sulfuric acid not only offered the active sites for formation of polypyrrole particles but also acted as dopant agents in PPy. The nanostructures of sunflower‐like silica/PPy nanocomposites and hollow PPy capsules were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The molecular structure and content of PPy were determined by Fourier transform infrared (FTIR) and thermal gravimetric analysis (TGA), respectively. The highest conductivity of nanocomposites is 2.4 S/cm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation, evaluation, and in vitro release study of O‐carboxymethyl chitosan nanoparticles loaded with gentamicin and salicylic acid
Authors: Ji Jingou , Hao Shilei , Dong Jin , Wu Danjun , Yang Bin , Xu Yi 
Published: August 2011

AbstractTo inhibit the ototoxicity of gentamicin (GM) and overcome the drawback related to chitosan (CS) nanoparticles preparation in acid solution, O‐carboxymethyl chitosan (O‐CMC) nanoparticles loaded with GM and salicylic acid (SA) were prepared by ionic cross‐linking method using calcium chloride as crosslinking agent. The Fourier transform infrared (FTIR) spectroscopy and X‐ray diffraction (XRD) were used to analyze the reaction of O‐CMC and crosslinking agent. The parameters of preparation of the compound nanoparticles including the concentration of O‐CMC, the mass ratio of O‐CMC to calcium chloride, and the feed ratio of SA to GM were investigated. The results showed that the obtained nanoparticles had a high zeta potential and drug‐loading capacity. The nanoparticles were characterized by a spherical morphology, with average size ranging from 148 to 345 nm and a narrow particle size distribution. In vitro release studies in phosphate buffer saline (pH 7.4) evidenced a burst release in the first 1 h, followed by a sustained release in the residual time. The release amount of SA and GM were approximately equal in 24 h, which indicated that the SA‐ and GM‐loaded O‐CMC nanoparticles are a promising carrier system for inhibiting the ototoxicity of GM. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of linear low‐density polyethylene/sepiolite nanocomposites
Authors: Shafiq Muhammad , Yasin Tariq , Saeed Shaukat 
Published: August 2011

AbstractLinear low‐density polyethylene (LLDPE)/sepiolite nanocomposites were prepared by melt blending using unmodified and silane‐modified sepiolite. Two methods were used to modify sepiolite: modification before heat mixing (ex situ) and modification during heat mixing (in situ). The X‐ray diffraction results showed that the position of the main peak of sepiolite remained unchanged during modification step. Infrared spectra showed new peaks confirming the development of new bonds in modified sepiolite and nanocomposites. SEM micrographs revealed the presence of sepiolite fibers embedded in polymer matrix. Thermogravimetric analysis showed that nanocomposites exhibited higher onset degradation temperature than LLDPE. In addition, in situ modified sepiolite nanocomposites exhibited higher thermal stability than ex situ modified sepiolite nanocomposites. The ultimate tensile strength and modulus of the nanocomposites were improved; whereas elongation at break was reduced. The higher crystallization temperature of some nanocomposite formulations revealed a heterogeneous nucleation effect of sepiolite. This can be exploited for the shortening of cycle time during processing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Thermoreversible supramolecular polyurethanes with self‐complementary quadruple hydrogen‐bonded end groups
Authors: Zhu Bo , Feng Zhicheng , Zheng Zhen , Wang Xinling 
Published: August 2011

AbstractIn this article, a new type of strongly dimerizing 2‐ureido‐4‐[1H]‐pyrimidinone (UPy) with amine group is synthesized and then used as end‐group to prepare a novel series of supramolecular polyurethanes (PUs). The effects of strong and well‐defined hydrogen bonding on material properties of PUs are studied. In these PUs, the UPy groups consequently serve as thermoreversible associations or the “hard blocks” and the bi‐functional PU chains act as the “monomers.” This theoretical hypothesis is proved by the results of dynamic mechanical thermal analysis (DMTA) and rheological test. Thermal analysis shows that the strong hydrogen bonds from end groups restrict the formation of their microcrystalline domains. The supramolecular PUs exhibit good mechanical performance and their self‐assemble mechanism is discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of nucleation on the brittle‐ductile transition temperature of impact‐resistant polypropylene copolymer: From the sight of phase morphology
Authors: Cheng Dong , Feng Jiachun , Yi Jianjun 
Published: August 2011

AbstractInfluence of α‐ and β‐nucleation on brittle‐ductile transition temperature (BDTT) of impact‐resistant polypropylene copolymers (IPCs) and their phase morphologies were comparatively investigated. Impact test showed that the BDTT of β‐nucleated IPC (β‐IPC) is ∼ 24°C lower than that of α‐nucleated one (α‐IPC). Structural characterizations including atomic force and scanning electron microscopic observations, small angle X‐ray scattering examination, and dynamical mechanical analysis revealed that dispersion of the ethylene‐propylene random copolymer‐rich (EPR‐rich) phase was finer in β‐IPC in comparison with that in α‐IPC. For the reason of looser lamellar arrangement, the portion of EPR‐rich components included in the interlamellar region of β‐IPC was higher than those of α‐IPC, which led to improved mobility for the amorphous polypropylene chains. It was proposed that the finer distribution of EPR‐rich phase, which might result from faster growth rate of the β‐crystal and looser lamellar arrangement of β‐spherulite, should be responsible for the improved impact‐resistance and lower BDTT in β‐IPC samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electrospun magnetic fibrillar polyarylene ether nitriles nanocomposites reinforced with Fe‐phthalocyanine/Fe3O4 hybrid microspheres
Authors: Meng Fanbin , Zhan Yingqing , Lei Yajie , Zhao Rui , Zhong Jiachun , Liu Xiaobo 
Published: August 2011

AbstractThe electrospinning method has been employed to fabricate ultrafine nanofibers of high‐performance polyarylene ether nitriles (PEN) and PEN/Fe‐phthalocyanine/Fe3O4 nanocomposite fibers for the first time. Through optimizing the operational conditions, such as polymer concentration, applied electric voltage, federate, and distance between needle tip and collector, bead‐free and uniform fibers with smooth surfaces and certain diameters were obtained. The morphology of the PEN nanofibers is correlated to the corresponding rheological behaviors of the polymer solutions. The nanocomposite fibers showed a beads‐in‐string structures without agglomeration after introducing the Fe‐phthalocyanine/Fe3O4 hybrid microspheres in the polymer fibers. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) reveal an enhanced thermal stability of the nanocomposite fibers after introducing the hybrids. The glass transition temperature (Tg) of the nanocomposite fibers increases by 10°C with 30 wt % hybrid microspheres, compared with those of the pure PEN fibers. The magnetic properties of the PEN/Fe‐phthalocyanine/Fe3O4 nanocomposite fibers are different from those of the hybrid microspheres. The hybrid microspheres in the composite nanofibers become magnetically harder with a much larger coercivity than that of the fillers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Analysis of dynamically scheduled tile algorithms for dense linear algebra on multicore architectures
Authors: Haidar Azzam , Ltaief Hatem , YarKhan Asim , Dongarra Jack 
Published: August 2011

SUMMARYThe objective of this paper is to analyze the dynamic scheduling of dense linear algebra algorithms on shared‐memory, multicore architectures. Current numerical libraries (e.g., linear algebra package) show clear limitations on such emerging systems mainly because of their coarse granularity tasks. Thus, many numerical algorithms need to be redesigned to better fit the architectural design of the multicore platform. The parallel linear algebra for scalable multicore architectures library developed at the University of Tennessee tackles this challenge by using tile algorithms to achieve a finer task granularity. These tile algorithms can then be represented by directed acyclic graphs, where nodes are the tasks and edges are the dependencies between the tasks. The paramount key to achieve high performance is to implement a runtime environment to efficiently schedule the execution of the directed acyclic graph across the multicore platform. This paper studies the impact on the overall performance of some parameters, both at the level of the scheduler (e.g., window size and locality) and the algorithms (e.g., left‐looking and right‐looking variants). We conclude that some commonly accepted rules for dense linear algebra algorithms may need to be revisited. Copyright © 2011 John Wiley & Sons, Ltd.
Behavioural activation for the treatment of low‐income, African American adolescents with major depressive disorder: a case series
Authors: Jacob Maryann , L. Keeley Mary , Ritschel Lorie , Craighead W. Edward 
Published: August 2011

Behavioural activation (BA) is a psychosocial treatment that has shown promise in the treatment of adults suffering from major depressive disorder (MDD). Recent studies have shown that BA may also be effective for treating depressed adolescents. There are no studies that have reported on the BA treatment of depressed and low‐income African American adolescents; thus, the current study reports on the effectiveness of a version of BA adapted for the treatment of African American adolescents who were diagnosed with MDD (n = 3). Participants were allowed to attend a maximum of 17 sessions of weekly psychotherapy. Based on results taken from structured interviews, two of the three participants no longer met criteria for MDD at the end of treatment, and the severity of clinician‐rated depressive symptoms and impairment decreased for all participants at post‐treatment assessment. Additionally, all participants and their caregivers reported satisfaction with treatment. Implications of these findings, study limitations and suggestions for future directions are discussed. Copyright © 2011 John Wiley & Sons, Ltd.Key Practitioner Message

Behavioural activation is an emerging evidence‐based psychotherapeutic treatment for adolescent depression.
African American adolescents in particular can benefit behavioural activation.
Behavioural activation is an intervention that can be utilized in settings with limited resources.
Straightforward Synthesis of All Stenusine and Norstenusine Stereoisomers
Authors: Müller Tobias , Dettner Konrad , Seifert Karlheinz 
Published: August 2011

AbstractAll the stereoisomers of stenusine (1) and norstenusine (21) have been efficiently synthesized by the asymmetric hydrogenation of pyridines. The (2R,3S)‐ and (2R,3R)‐isomers of 1, that are difficult to prepare, have been synthesized for the first time using a chemoenzymatic approach in eight steps with an 8 % total yield. All the target compounds were obtained in good stereochemical purity by using very simple and inexpensive reagents and auxiliaries.
Simulations of chemical transport and reaction in a suspension of cells I: an augmented forcing point method for the stationary case
Authors: Yao Lingxing , Fogelson Aaron L. 
Published: August 2011

SUMMARYA novel augmented forcing point method is presented to solve the problem of chemical transport in the fluid outside of a collection of suspended cells coupled with chemical reactions on the surfaces of the cells. In this method, the chemical concentrations and the forcing function values are determined simultaneously from an augmented system of equations. The method is more stable and accurate than predictor‐corrector‐type forcing point methods, yields the same solution as a corresponding ghost cell method with much less computational cost, and provides solutions that are pointwise second‐order accurate in space and time, even for closely‐spaced cells. Copyright © 2011 John Wiley & Sons, Ltd.
A Boyden chamber‐based method for characterization of astrocyte protrusion localized RNA and protein
Authors: Thomsen Rune , Lade Nielsen Anders 
Published: August 2011

AbstractThe Boyden chamber assay has been developed for various cell migration and invasion protocols. One variant of the Boyden chamber assay is the pseudopodium isolation assay, which has been developed to identify RNA and proteins localized in pseudopodia cell protrusions. Astrocytes are the most abundant cell type in the CNS and typically extend long cellular protrusions. Increasing interest emerges concerning for example the growth mechanisms and functions of astrocytes in respect to brain development, re‐uptake of neurotransmitters in the synaptic cleft and glial scar formation. Protein and RNA localization mechanisms have been extensively examined in neurons and shown to play pivotal roles for the functional presence of specific protein components in neuronal protrusions. Here we present a simple Boyden chamber based method to isolate astrocyte cell protrusions for biochemical analysis. We have succeeded in isolating protrusion localized RNA and protein from the mouse astrocyte cell line, C8‐S, and mouse primary astrocytes. This is exemplified in biochemical analyses showing specific localization of the mRNA for Ras‐related protein (Rab13), Plakophilin‐4 (Pkp4), Ankyrin Repeat Domain 25 (Ankrd25), and inositol polyphosphate‐1‐phosphatase (Inpp1) in the protrusions of both C8‐S cells and primary astrocytes. Concordant, the Pkp4 protein was also predominantly localized in the protrusions of C8‐S and primary astrocytes. The described methodology can be the basis for both genome wide and specific descriptive and functional studies of RNA and protein localization in the protrusions of astrocytes which could contribute considerably to the existing knowledge of astrocyte functions in the CNS. © 2011 Wiley‐Liss, Inc.
Chondrogenic differentiation of adult mesenchymal stem cells and embryonic cells in collagen scaffolds
Authors: Ng Karen K. , Thatte Hemant S. , Spector Myron 
Published: August 2011

AbstractMany cell types and cellular microenvironments have been explored for articular cartilage tissue engineering. We compared the potential of bone marrow‐derived mesenchymal stem cells (MSCs) and P19 embryonic carcinoma cells (ECCs), a pluripotent derivative of embryonic stem cells (ESCs), for cartilage histogenesis in porous collagen scaffolds in vitro. We found that while both MSCs and ECCs express α‐smooth muscle actin (α‐SMA), only MSCs exhibit condensation and contraction necessary for cartilage histogenesis. Furthermore, histology confirmed that only MSCs exhibited sulfated glycosaminoglycans and collagen type II formation after 14 days in culture. We conclude that MSCs appear to be superior over ECCs for cartilage regeneration under particular culture conditions. The α‐SMA‐expressing ECCs may not have contracted due to the absence of actin unit polymerization or the absence of myosin molecules. Our observations may explain the absence of a contractile scar in fetal wound healing. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Optimized conditions for mesenchymal stem cells to differentiate into osteoblasts on a collagen/hydroxyapatite matrix
Authors: Prosecká E. , Rampichová M. , Vojtová L. , Tvrdík D. , Melčáková Š. , Juhasová J. , Plencner M. , Jakubová R. , Jančář J. , Nečas A. , Kochová P. , Klepáček J. , Tonar Z. , Amler E. 
Published: August 2011

AbstractCollagen/hydroxyapatite (HA) composite scaffolds are known to be suitable scaffolds for seeding with mesenchymal stem cells (MSCs) differentiated into osteoblasts and for the in vitro production of artificial bones. However, the optimal collagen/HA ratio remains unclear. Our study confirmed that a higher collagen content increased scaffold stiffness but that a greater stiffness was not sufficient for bone tissue formation, a complex process evidently also dependent on scaffold porosity. We found that the scaffold pore diameter was dependent on the concentration of collagen and HA and that it could play a key role in cell seeding. In conclusion, the optimal scaffold for new bone formation and cell proliferation was found to be a composite scaffold formed from 50 wt % HA in 0.5 wt % collagen I solution. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011.
Biosensor Förster resonance energy transfer detection by the phasor approach to fluorescence lifetime imaging microscopy
Authors: Hinde Elizabeth , Digman Michelle A. , Welch Christopher , Hahn Klaus M. , Gratton Enrico 
Published: August 2011

AbstractWe present here the phasor approach to biosensor Förster resonance energy transfer (FRET) detection by fluorescence lifetime imaging microscopy (FLIM) and show that this method of data representation is robust towards biosensor design as well as the fluorescence artifacts inherent to the cellular environment. We demonstrate this property on a series of dual and single chain biosensors, which report the localization of Rac1 and RhoA activity, whilst performing concomitant ratiometric FRET analysis on the acquired FLIM data by the generalized polarization (GP) approach. We then evaluate and compare the ability of these two methods to quantitatively image biosensor FRET signal as a function of time and space. We find that with lifetime analysis in the phasor plot each molecular species is transformed into a two‐dimensional coordinate system where independent mixtures of fluorophores can be distinguished from changes in lifetime due to FRET. This enables the fractional contribution of the free and bound state of a dual chain biosensor or the low and high FRET species of a single chain biosensor to be quantified in each pixel of an image. The physical properties intrinsic to each biosensor design are also accurately characterized by the phasor analysis; thus, this method could be used to inform biosensor optimization at the developmental stage. We believe that as biosensors become more sophisticated and are multiplexed with other fluorescent molecular tools, biosensor FRET detection by the phasor approach to FLIM will not only become imperative to their use but also their advancement. Microsc. Res. Tech., 2011. © 2011 Wiley‐Liss, Inc.
A simple synthesis of trisubstituted quinolines through transesterification
Authors: Patil Dipti R. , Deshmukh Madhukar B. , Salunkhe Sonali M. , Anbhule Prashant V. 
Published: August 2011

AbstractAn efficient and simple method has been reported for the synthesis of 2,3,4‐trisubstituted quinolines through zwitterion intermediate under reflux condition in presence of sulfuric acid. The formed dicarboxylate subsequently undergoes transesterification in various alcohols with good yields. Most of the synthesized compounds are newly reported characterized by spectroscopic method. J. Heterocyclic Chem., (2011).
An efficient synthesis of 2,3,4‐trisubstituted quinolines through alkynylation‐cyclization at ambient temperature
Authors: Patil Dipti R. , Salunkhe Sonali M. , Deshmukh Madhukar B. , Anbhule Prashant V. 
Published: August 2011

AbstractA series of 2,3,4‐trisubstituted quinoline derivatives have been synthesized by reactions between 2‐aminoaryl ketones and dialkyl acetylenedicarboxylate. The synthetic pathway allows for the direct construction of said quinoline derivatives in pyridine/ethanol at ambient temperature through a zwitterion intermediate. J. Heterocyclic Chem., (2011)
Molecular iodine‐catalyzed one‐pot synthesis of tetrahydrobenzo[a]xanthene‐11‐one and diazabenzo[a]anthracene‐9,11‐dione derivatives under microwave irradiation
Authors: Sun X. J. , Zhou J. F. , Zhao P. S. 
Published: August 2011

AbstractAn efficient one‐pot condensation of β‐naphthol, aldehydes, and cyclic 1,3‐dicarbonyl compounds has been achieved with molecular iodine as a catalyst under microwave irradiation, thus a variety of tetrahydrobenzo[a]xanthene‐11‐one and diazabenzo[a]anthracene‐9,11‐dione derivatives were prepared in good yields. J. Heterocyclic Chem., (2011).
2‐Arylhydroxynitroindoles: A new procedure for the cleavage of aryl methyl ethers
Authors: Kokurkina G. V. , Dutov M. D. , Shevelev S. A. 
Published: August 2011

AbstractA new procedure for the cleavage of aryl methyl ethers was developed. On this basis representatives of new types of 2‐arylhydroxynitroindoles were synthesized. J. Heterocyclic Chem., (2011).