bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graft copolymerization and characterization of 2‐hydroxyethyl methacrylate onto jute fiber by photoirradiation
Authors: Khan Ferdous , Ahmad S. R. 
Published: June 2006

AbstractUV radiation induced graft copolymerization of 2‐hydroxyethyl methacrylate onto natural lignocellulose (jute) fiber was carried out by two methods: simultaneous irradiation and grafting and preirradiation grafting. 1‐Hydroxycyclohexyl‐phenylketone was used as the photoinitiator in both methods. In the former method, the variation of the graft weight was measured for different values of radiation exposure time and the concentrations of both the monomer and photoinitiator. The latter method produced up to 76% graft weight compared to 45% obtained with the former method. The preirradiation method offers better control of the homopolymerization reaction compared to that afforded by the other method. The optimum value of the reaction parameters on the graft weight was evaluated. The mechanical properties of grafted samples were found to be drastically different from those of the as‐received ones and the effect was proportional to the percentage of graft weight. Differential scanning calorimetry studies showed that the percentage of graft add‐on of hydroxyethyl methacrylate with jute had a significant effect on the thermal properties. IR studies indicated the degree of grafting could be estimated by correlating the band intensities with the graft weight. The jute samples grafted with poly(hydroxyethyl methacrylate) at a level of 12% graft weight exhibited a maximum 20% increase in hydrophilicity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2898–2910, 2006
Processing and morphology of molecularly imprinted nylon thin films
Authors: Richter Asta , Gibson Ursula J. , Nowicki Marek , BelBruno Joseph J. 
Published: June 2006

AbstractThe characterization of thin, selectively imprinted films of nylon‐6 was performed. Amino acids were used as template molecules. Spin‐cast films were prepared with sizes ranging from 2 μm to 300 nm, depending on the nylon and template concentration in the casting solution. The morphological characteristics of the film surface were examined by atomic force microscopy, and the structure within the films was observed by freeze‐fracture scanning electron microscopy. The film activity was clearly coordinated with the appearance of nanometer‐sized pores both on the surface and within the film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2919–2926, 2006
Curing kinetics and thermal property characterization of o‐CFER/MeTHPA/O‐MMT nanocomposite
Authors: Gao Jungang , Zhao Min , Li Gang 
Published: June 2006

AbstractThe kinetics of the cure reaction for a system of o‐cresol‐formaldehyde epoxy resin (o‐CFER), 3‐methyl‐tetrahydrophthalic anhydride (MeTHPA), N,N‐dimethyl‐benzylamine, and organic montmorillonite(O‐MMT) were investigated by means of X‐ray diffraction (XRD) and differential scanning calorimetry (DSC). The XRD result indicates that an exfoliated nanocomposite was obtained. The analysis of DSC data indicated the behavior was shown in the first stages of the cure for the system, which could be well described by the model proposed by Kamal. In the later stages, the reaction is mainly controlled by diffusion, and diffusion factor, f(α), was introduced into Kamal's equation. In this way, the curing kinetics was predicted well over the entire range of conversion. Molecular mechanism for curing reaction was discussed. The thermal degradation kinetics of the system were investigated by thermogravimetric analysis (TGA), which revealed that with the increase of O‐MMT content, TG curves shift to higher temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3023–3032, 2006
Synthesis of sulfonated rubber ionomers by the ring‐opening reaction of epoxidized styrene–butadiene rubber, their characterization, and their properties
Authors: Xie Hong‐Quan , Chen Yong , Yang Wei , Xie Dong 
Published: June 2006

AbstractA novel method for the synthesis of the sulfonate ionomer of styrene‐co‐butadiene rubber (SBR) was developed. SBR was first epoxidized by performic acid formed from hydrogen peroxide and formic acid in situ in solution, and this was followed by a ring‐opening reaction with an aqueous solution of NaHSO3. The optimum conditions for the epoxidation of SBR in the presence of a phase‐transfer catalyst and for the ring‐opening reaction of epoxidized SBR with an aqueous solution of NaHSO3 were studied. During the epoxidation of SBR, a phase‐transfer catalyst, such as poly(ethylene glycol), could enhance the conversion of double bonds to epoxy groups. During the ring‐opening reaction, both the phase‐transfer catalyst and ring‐opening catalyst were necessary to enhance the conversion of the epoxy groups to ionic groups. The addition of Na2SO3 to the reaction mixture was important to obtain 100% conversion. The products were characterized with Fourier transform infrared spectrophotometry, 1H‐NMR spectroscopy, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). DSC showed that the sodium sulfonate SBR ionomer possessed a dissociation temperature of ionic domains at 110°C, which appeared as black spots under TEM, after the sodium ions of the ionomer were substituted by lead ions. Some properties of the sodium ionomer, such as the water absorbency, oil absorbency, and dilute solution behavior, were studied. With increasing ionic groups, the water absorbency of the ionomer increased, whereas the oil absorbency decreased. The dilute solution viscosity of the ionomer increased abruptly with increasing ionic group content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3090–3096, 2006
The Role of the HPA Axis in Psychiatric Disorders and CRF Antagonists as Potential Treatments
Authors: Keller Paul A. , McCluskey Adam , Morgan Jody , O'Connor Sean M. J. 
Published: June 2006

AbstractAn overview of the links between the Hypothalamic‐Pituitary‐Adrenal (HPA) axis and psychiatric disorders is presented. The current treatments are outlined, indicating that they are insufficient to meet the needs of those that suffer from these affective disorders. Therefore, there is an urgent need for the generation of new therapeutics, in particular, against new targets. The association of the corticotrophin releasing factor (CRF) and the HPA axis indicates that CRF antagonists should be beneficial as potential therapeutics.
3D Pharmacophore Models for 1,2,3,4‐Tetrahydroisoquinoline Derivatives Acting as Anticonvulsant Agents
Authors: De Luca Laura , Gitto Rosaria , Barreca Maria Letizia , Caruso Roberta , Quartarone Silvana , Citraro Rita , De Sarro Giovambattista , Chimirri Alba 
Published: June 2006

AbstractA 3D pharmacophore model predicting anticonvulsant activity was obtained for a series of 6,7‐dimethoxy‐1,2,3,4‐tetrahydroisoquinoline derivatives recently disclosed as a new class of noncompetitive AMPA receptor antagonists. The training set included 17 compounds with varying potency against audiogenic seizures in DBA/2 mice. The best statistical hypothesis, generated with the HypoGen module of Catalyst 4.9, consisted of five features: two hydrogen bond acceptors, two hydrophobic features, and one hydrophobic aromatic region, providing a model with a correlation coefficient of 0.919. The obtained model was an efficient tool in the design of some new anticonvulsant agents containing the tetrahydroisoquinoline scaffold. Moreover, in order to explain the different degree of efficacy of the newly designedN‐substituted derivatives, excluded volumes were also considered.
Model‐based quantification of the volatility of options at transaction level with extended count regression models
Authors: Czado Claudia , Kolbe Andreas 
Published: June 2006

AbstractIn this paper, we elaborate how Poisson regression models of different complexity can be used in order to model absolute transaction price changes of an exchange‐traded security. When combined with an adequate autoregressive conditional duration model, our modelling approach can be used to construct a complete modelling framework for a security's absolute returns at transaction level, and thus for a model‐based quantification of intraday volatility and risk. We apply our approach to absolute price changes of an option on the XETRA DAX index based on quote‐by‐quote data from the EUREX exchange and find that within our Bayesian framework a Poisson generalized linear model (GLM) with a latent AR(1) process in the mean is the best model for our data according to the deviance information criterion (DIC). While, according to our modelling results, the price development of the underlying, the intrinsic value of the option at the time of the trade, the number of new quotations between two price changes, the time between two price changes and the Bid–Ask spread have significant effects on the size of the price changes, this is not the case for the remaining time to maturity of the option. Copyright © 2006 John Wiley & Sons, Ltd.
A mixed co‐rotational formulation of 2D beam element using vectorial rotational variables
Authors: Li Z. X. 
Published: June 2006

AbstractBased on a co‐rotational framework, a three‐noded iso‐parametric mixed element formulation for large displacement analysis of 2D beam was presented, this formulation is free of membrane/shear locking problems. Firstly, the co‐rotational framework was fixed at the internal node of the element, which translates and rotates rigidly with this node, but does not deform with the element. Then, a set of vectorial rotational variables were defined to describe accurately the element deformation, these rotational variables may have different connotations in an incremental solution procedure. Thirdly, Green strain and independently assumed strain fields were introduced in calculating the mixed Hellinger–Reissner functional, and the internal force vector was derived by enforcing the stationarity to the mixed functional, thereafter, the element tangent stiffness matrix was calculated from the internal force vector by differentiating it with respect to local variables, and a symmetric element tangent stiffness matrix was achieved. Finally, several examples were analysed to illustrate the reliability and efficiency of the proposed procedure in modelling of 2D frame structures with large displacements and large rotations. Copyright © 2006 John Wiley & Sons, Ltd.
A lattice Boltzmann method for shock wave propagation in solids
Authors: Xiao Shaoping 
Published: June 2006

AbstractThis paper proposes a new lattice Boltzmann (LB) method for the study of shock wave propagation in elastic solids. The method, which implements a flux‐corrected transport (FCT) algorithm, contains three stages: collision, streaming, and correction. In the collision stage, distribution functions are updated. In the streaming stage, the distribution functions are shifted between lattice points. Generally, a partial differential equation (PDE) is solved in the streaming stage, and finite element methods are employed to support the use of unstructured meshes in the LB method. The FCT algorithm is used in the correction stage to revise the distribution functions at lattice points, so fluctuations behind shock wave fronts can be eliminated efficiently. In this method, schemes for shock wave reflection at fixed and free boundaries are developed based on the bounce‐back technique. A similar technique is used to treat wave reflection and transmission at material interfaces of composites. Several one‐dimensional examples show that this LB‐FCT method can provide ideal depictions of shock wave propagation in structures, especially composite structures. Copyright © 2006 John Wiley & Sons, Ltd.
Cognitive integrated motion generation for environmental adaptive robots
Authors: Onishi Masaki , Odashima Tadashi , Luo Zhiwei 
Published: June 2006

AbstractRecently, active researches have been performed to increase a robot's intelligence so as to realize dexterous tasks in complex environments such as in the street or homes. However, since skillful human‐like task ability is so difficult to formulate for the robot, not only the analytical and theoretical control researches but also the direct human motion mimetic approach is necessary. In this paper, we propose that to realize the environmental interactive task, it is insufficient to replay the human motion alone. We show a novel motion generation approach to integrate the cognitive information into mimickry of human motions so as to realize the final complex task by the robot. As a detailed example of the task, we consider how to carry up a human by cooperating two hands. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(3): 62–70, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20349
Modulating responsiveness of human TLR7 and 8 to small molecule ligands with T‐rich phosphorothiate oligodeoxynucleotides
Authors: Jurk Marion , Kritzler Andrea , Schulte Bettina , Tluk Sibylle , Schetter Christian , Krieg Arthur M. , Vollmer Jörg 
Published: June 2006

AbstractToll‐like receptors (TLR) 7 and 8 are closely related members of the TLR family of pathogen‐associated molecular pattern recognition receptors and have an important function in activation of innate immune responses upon viral infection. TLR7 can be activated selectively by the guanosine analogue loxoribine, whereas the imidazoquinoline derivative Resiquimod (R‐848) activates both TLR7 and TLR8. We demonstrate that co‐incubation of R‐848 with thymidine homopolymer oligodeoxynucleotides (ODN) significantly increased activity of R‐848 on TLR8‐expressing HEK 293 cells, but abolished TLR7‐mediated signaling. Similarly, the combination of loxoribine and thymidine ODN redirected the stimulatory effect of loxoribine away from TLR7, and toward TLR8. This alteration in ligand specificity was demonstrated both in TLR‐transfected HEK cells, and also in human PBMC, with a corresponding change in cytokine production away from IFN‐α secretion by TLR7‐expressing plasmacytoid DC and toward IL‐12, TNF‐α and IFN‐γ secretion by TLR8‐expressing monocytes and NK cells. These results demonstrate an unexpected plasticity in the ligand specificities of TLR7 and TLR8, and suggest a novel sequence‐selective interaction between these receptors and synthetic phosphorothioate ODN.
Ionic Liquid as Catalyst and Reaction Medium – A Simple, Efficient and Green Procedure for Knoevenagel Condensation of Aliphatic and Aromatic Carbonyl Compounds Using a Task‐Specific Basic Ionic Liquid
Authors: Ranu Brindaban C. , Jana Ranjan 
Published: June 2006

AbstractThe basic ionic liquid 1‐butyl‐3‐methylimidazolium hydroxide, [bmIm]OH, efficiently catalyzes Knoevenagel condensation without requirement of any organic solvent. A wide range of aliphatic and aromatic aldehydes and ketones easily undergo condensations with diethyl malonate, malononitrile, ethyl cyanoacetate, malonic acid and ethyl acetoacetate. The reactions proceed at room temperature and are very fast (10–30 min). However, the most significant feature of this methodology is the condensation of aliphatic aldehyde with diethyl malonate, which is not very easy to achieve by conventional reagents, and was not addressed adequately in literature providing a general and convenient procedure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Analysis and validation of the phosphorylated metabolites of two anti‐human immunodeficiency virus nucleotides (stavudine and didanosine) by pressure‐assisted CE‐ESI‐MS/MS in cell extracts: Sensitivity enhancement by the use of perfluorinated acids and alcohols as coaxial sheath‐liquid make‐up constituents
Authors: Bezy Vincent , Chaimbault Patrick , Morin Philippe , Unger Steve E. , Bernard Marie‐Charlotte , Agrofoglio Luigi A. 
Published: June 2006

AbstractA CE method utilizing triple quadrupole electrospray (ES) MS (MS/MS) detection was developed and validated for the simultaneous measurement of nucleoside 5'‐triphosphate and 5'‐monophosphate anabolites of the anti‐HIV (human immunodeficiency virus) didanosine (ddAMP, ddATP) and stavudine (d4TMP, d4TTP), among a pool of 14 endogenous 5'‐mono‐, di‐, and triphosphate nucleosides. These compounds were spiked and extracted from peripheral blood mononuclear cells (PBMCs) which are the sites of HIV replication and drug action. An acetic acid/ammonia buffer (pH 10, ionic strength of 40 mM) was selected as running electrolyte, and the separation was performed by the simultaneous application of a CE voltage of +30 kV and an overimposed pressure of 28 mbar (0.4 psi). The application of pressure assistance was needed to provide stable ES conditions for successful coupling. The coupling was carried out with a modified sheath‐flow interface, with one uninterrupted capillary (80 cm× 50 µm id; 192 µm od) in a dimension that fits into the ESI needle to get a stable ion spray. Some CE‐MS parameters such as overimposed pressure, sheath‐liquid composition, sheath‐liquid and sheath‐gas flow rates, ES voltage, and the CE capillary position were optimized in order to obtain an optimal sensitivity. The use of perfluorinated alcohols and acids in the coaxial sheath‐liquid make‐up (2,2,2‐trifluoroethanol + 0.2 mM tridecafluoroheptanoic acid) appeared to provide the best MS sensitivity and improve the stability of spray. The linearity of the CE‐MS and CE‐MS/MS methods was checked under these conditions. Validation parameters such as accuracy, intraday and interday precision, and LOQs were determined in CE‐MS/MS mode. Finally, the quantitation of d4T‐TP and ddA‐TP was validated in this CE‐MS/MS system.
Rapid analysis of atorvastatin calcium using capillary electrophoresis and microchip electrophoresis
Authors: Guihen Elizabeth , Sisk Garry D. , Scully Norma M. , Glennon Jeremy D. 
Published: June 2006

AbstractIn this work, a capillary electrophoretic method for the rapid quantitation of atorvastatin (AT) in a lipitor tablet was investigated and developed. Method development included studies of the effect of applied potential, buffer concentration, buffer pH, and hydrodynamic injection time on the electrophoretic separation. The method was validated with regard to linearity, precision, specificity, LOD, and LOQ. The optimum electrophoretic separation conditions were 25 mM sodium acetate buffer at pH 6, with a separation voltage of 25 kV using a 50 µm capillary of 33 cm total length. Sodium diclofenac was used as an internal standard. Analysis of AT in a commercial lipitor tablet by electrophoresis gave quite high efficiency, coupled with an analysis time of less than 1.2 min in comparison to LC. Once the separation was optimized on capillary, it was further miniaturized to a microchip platform, with linear imaging UV detection using microchip electrophoresis (MCE). Linear imaging UV detection allowed for real‐time monitoring of the analyte movement on chip, so that the optimum separation time could be easily determined. This microchip electrophoretic method was compared to the CE method with regard to speed, efficiency, precision, and LOD. This work represents the most rapid and first reported analysis of AT using MCE.
Capillary electrophoresis for the characterization of the complex dendrimeric contrast agent Gadomer
Authors: Vetterlein Kai , Büche Karlo , Hildebrand Michael , Scriba Gerhard K. E. , Lehmann Jochen 
Published: June 2006

AbstractA CE method for the characterization of the complex dendrimeric contrast agent Gadomer has been developed and validated. The method was capable of separating the target substance Gadomer 24 from related dendrimers containing amino or carboxyl functions and from impurities of lower molecular weight. The compounds were separated in a fused‐silica capillary. The optimized BGE consisted of 15 mM sodium phosphate, pH 6.3, containing 0.5 mM hexadecyltrimethylammonium bromide. The assay was validated with regard to linearity, specificity, accuracy, LOD and LOQ as well as robustness according to the guidelines of the International Conference on Harmonization. The method allows the determination of the purity and stability of the drug substance Gadomer as well as its injectable formulation. On the basis of the present study, a strategy for the quality assurance and quality control of the complex dendrimeric drug candidate Gadomer may be devised. The method may therefore serve as a key component in a set of analytical methodologies designed to assure and control the reproducible quality and safety of this innovative product. To the best of our knowledge, this is the first work reporting a validated method for the characterization, impurity profiling, and stability testing of a dendrimeric agent designed for clinical use.
Behaviour of the double concave Friction Pendulum bearing
Authors: Fenz Daniel M. , Constantinou Michael C. 
Published: June 2006

AbstractThe double concave Friction Pendulum (DCFP) bearing is an adaptation of the well‐known single concave Friction Pendulum bearing. The principal benefit of the DCFP bearing is its capacity to accommodate substantially larger displacements compared to a traditional FP bearing of identical plan dimensions. Moreover, there is the capability to use sliding surfaces with varying radii of curvature and coefficients of friction, offering the designer greater flexibility to optimize performance. This paper describes the principles of operation of the bearing and presents the development of the force–displacement relationship based on considerations of equilibrium. The theoretical force–displacement relationship is then verified through characterization testing of bearings with sliding surfaces having the same and then different radii of curvature and coefficients of friction. Lastly, some practical considerations for analysis and design of DCFP bearings are presented. Copyright © 2006 John Wiley & Sons, Ltd.
Organised beam‐hopping technique with adaptive transmission mode selection for mobile communication systems
Authors: Hu Honglin , Weckerle Martin , Luo Jijun , Schulz Egon 
Published: June 2006

AbstractOpportunistic beamforming (OB) technique induces random fading, hence increases the performance of multiuser diversity greatly. However, if the number of active mobile stations (MS) is small, the performance of the OB technique is not so satisfactory. Moreover, the OB technique relies on the training sequences to estimate the real‐time signal to interference plus noise ratio (SINR) of each activated beam (or weighting vector) for each MS, thus costs a large amount of radio resources. In this paper, we propose a new organised beam‐hopping (OBH) technique which could achieve good performance in the scenarios of both large and small number of MSs, and highly reduce the uplink traffic and signal processing at the base station (BS). The throughput performance of the OBH‐based system is analysed. In addition, based on the required quality‐of‐service (QoS) of the MS, we develop an adaptive transmission mode selection (ATMS) scheme for the OBH‐based systems. Copyright © 2006 AEIT.