bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the effects of polyethylenimine and maleated polypropylene coupling agents on the properties of cellulose‐reinforced polypropylene composites
Authors: González‐Sánchez C. , González‐Quesada M. , de la Orden M. U. , Urreaga J. Martínez 
Published: August 2008

AbstractThe desire to improve the properties of cellulose‐reinforced composites while producing them by methods as similar as possible to those used on an industrial scale is one of the driving forces in this field of research. In this work, extensive research for determining the mechanical, thermal, rheological, and physical properties of novel cellulose‐reinforced polypropylene composites containing a polyethylenimine (PEI) coupling agent was conducted. A comparison of their properties with those of reference composites without any coupling agent or containing a maleated polypropylene (MAPP) coupling agent was also carried out. The presence of the PEI coupling agent mainly gave rise to a substantial increase in the tensile and flexural strengths and elongations as well as the impact strength, heat deflection temperature (HDT), melt volume flow index, and water absorption of PEI‐containing composites in comparison with composites without any coupling agent added. However, the increases achieved in the tensile and flexural composite strengths and HDT were lower than those achieved with the MAPP coupling agent mainly for composites containing 50 wt % cellulose fibers. On the other hand, PEI‐containing composites exhibited, in most cases, larger elongations and energies required to break in tensile tests as well as larger impact strengths, melt volume flow indices, and water absorption percentages than MAPP‐containing composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of expandable graphite on the properties of intumescent flame‐retardant polyurethane foam
Authors: Thirumal M. , Khastgir Dipak , Singha Nikhil K , Manjunath B. S. , Naik Y. P. 
Published: August 2008

AbstractWater‐blown rigid polyurethane foam (PUF) with two different particle sizes (180 and 300 μm) of expandable graphite (EG) as a flame‐retardant additive were prepared, and the effects on the mechanical, morphological, water absorption, thermal conductivity, thermal, and flame‐retardant properties were studied. In this investigation, EG content was varied from 5 to 50 php by weight. The mechanical properties of PUF decreased with increasing EG loading in both cases. The water absorption of the PUF increased with an increase in the EG loading mainly because of the collapse of foam cells, as evidenced from the scanning electron microscopy pictures. The thermal conductivity of the EG‐filled PUF showed that the insulation properties decreased with EG loading. The flame‐retardant properties (limiting oxygen index and char yield measurement) of the PUF improved with increasing EG loading. PUF filled with the higher particle size EG showed better mechanical properties and fire‐retardant properties than the PUF filled with the lower particle size EG. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Melting behavior and isothermal crystallization kinetics of polypropylene/metallocene‐catalyzed polyethylene elastomer blends
Authors: Qin Jianglei , Zhang Shiqi , Li Zhiting 
Published: August 2008

AbstractPolypropylene (PP)/metallocene‐catalyzed polyethylene elastomer (mPE) blends were prepared in a twin‐screw extruder. The melting behavior, crystallization behavior, and isothermal crystallization kinetics of the blends were studied with differential scanning calorimetry. The results showed that PP and mPE were partially miscible and that the addition of mPE shifted the melting peak of PP to a lower temperature but the crystallization temperature to a higher temperature, demonstrating a dilution effect of mPE on PP. The isothermal crystallization kinetics of the blends were described with the Avrami equation. The values of the Avrami exponent indicated that the nucleation mechanism of the blends was heterogeneous, the growth of spherulites was almost three‐dimensional, and the crystallization mechanism of PP was not affected much by mPE. At the same time, the Avrami exponents of the blends were higher than that of pure PP, and this showed that the addition of mPE helped PP to form more perfect spherulites. The crystallization rate of PP was increased by mPE because the dilution effect of mPE on PP increased the mobility of PP chains. The crystallization activation energy was estimated with the Arrhenius equation, and the nucleation constant was determined by the Hoffman–Lauritzen theory. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Kim Jong‐Il of North Korea: in the shadow of his father
Authors: Post Jerrold M. 
Published: August 2008

AbstractThis paper explores the political personality of North Korea's leader, Kim Jong‐Il, particularly in the context of his succession from his father, the founding leader Kim Il‐Sung. Drawing upon what is known of Kim Jong‐Il's childhood and family life, the paper examines the key personality formations that have shaped his political persona and leadership style, particularly his narcissism, paranoia and lack of empathy. Eccentric, reclusive and self‐indulgent, Kim is depicted as an emotionally volatile, narcissistic personality who indulges in hedonistic behavior while ignoring the privations of his people. Copyright © 2004 Cornell University Press.
Formt die Technik die Musik? Montageästhetik zu Beginn des 20. Jahrhunderts
Authors: Braun Hans‐Joachim , Ungeheuer Elena 
Published: August 2008

AbstractDoes technology shape music? Aesthetics of assembly at the beginning of the 20th century. This article deals with the relationship between assembly in production technology and similar processes in musical composition. Can composers like Eric Satie, Igor Strawinsky or George Antheil, who used assembly methods in some of their compositions, be called assemblers? The authors point out that all three composers used assembly methods in different ways and with different purposes. Applying a theoretical approach inspired by media studies they come to the conclusion that the conditions under which musical works using assembly methods are shaped do not originate in technology but in the aesthetic convictions of the composer. Apart from assembly methods there are many other compositional principles the composer relies on. Technology may inspire music but does not determine the musical outcome.
Tonpsychologie und Musikforschung als Katalysatoren wissenschaftlich‐experimenteller Praxis und der Methodenlehre im Kreis von Carl Stumpf
Authors: Klotz Sebastian 
Published: August 2008

AbstractTone psychology and music research as catalysts of experimental‐scientific practice and methodology in the circle of Carl Stumpf. The study of acoustics, harmonics and of music has been providing scientific models since Greek Antiquity. Since the early modern ages, two separate cultures began to emerge out of the study of music: a technical acoustics and an aesthetically and philosophically inspired musical criticism. In the writings of Johann Friedrich Herbart (1811) a scientific approach to musical aesthetics and to music perception is taking shape that reinstalls the listening process as a highly complex and logical phenomenon. By opening music for a scientific psychological investigation, Herbart pioneered the physiologically and acoustically grounded seminal work by Hermann von Helmholtz On the sensations of tone (1863) which the author considered a prerequisite for musical aesthetics and music theory. Helmholtz in turn inspired the philosopher and psychologist Carl Stumpf to further investigate musical perception (beginning in 1883). To Stumpf, it provided a paradigm for experimental psychology as mental functions and phenomena could be studied in detail. These functions and phenomena are the actual objects of scientific study in Stumpf's inductive and descriptive psychology. Combining insights from statistics, ethnology, anthropology, psychoacoustics and the cultural history of mankind, Stumpf and his team developed a new blend of science which absorbs styles of reasoning, analytical procedures and academic convictions from natural history, the natural sciences and the humanities but at the same time identifies shortcomings of these approaches that fail to grasp the complexities of psychic functions. Despite their reliance on the quasi‐objective phonograph and despite their commitment to objectivity, precision and measurement, mental phenomena relating to tonal perception and to music provided too complex a challenge to be easily articulated and shared by the scientific community after 1900. The essay illustrates these tensions against the background of a history of objectivity.
Production, purification, and characterization of human α1 proteinase inhibitor from Aspergillus niger
Authors: Chill Liat , Trinh Loc , Azadi Parastoo , Ishihara Mayumi , Sonon Roberto , Karnaukhova Elena , Ophir Yakir , Golding Basil , Shiloach Joseph 
Published: August 2008

AbstractHuman alpha one proteinase inhibitor (α1‐PI) was cloned and expressed in Aspergillus niger, filamentious fungus that can grow in defined media and can perform glycosylation. Submerged culture conditions were established using starch as carbon source, 30% dissolved oxygen concentration, pH 7.0 and 28°C. Eight milligrams per liter of active α1‐PI were secreted to the growth media in about 40 h. Controlling the protein proteolysis was found to be an important factor in the production. The effects of various carbon sources, pH and temperature on the production and stability of the protein were tested and the product was purified and characterized. Two molecular weights variants of the recombinant α1‐PI were produced by the fungus; the difference is attributed to the glycosylated part of the molecule. The two glycoproteins were treated with PNGAse F and the released glycans were analyzed by HPAEC, MALDI/TOF‐MS, NSI‐MSn, and GC‐MS. The MALDI and NSI‐ full MS spectra of permethylated N‐glycans revealed that the N‐glycans of both variants contain a series of high‐mannose type glycans with 5–20 hexose units. Monosaccharide analysis showed that these were composed of N‐acetylglucos‐amine, mannose, and galactose. Linkage analysis revealed that the galactosyl component was in the furanoic conformation, which was attaching in a terminal non‐reducing position. The Galactofuranose‐containing high‐mannnose type N‐glycans are typical structures, which recently have been found as part of several glycoproteins produced by Aspergillus niger. Biotechnol. Bioeng. 2009; 102: 828–844. © 2008 Wiley Periodicals, Inc.
Investigation of protein binding affinity and preferred orientations in ion exchange systems using a homologous protein library
Authors: Chung Wai Keen , Hou Ying , Freed Alexander , Holstein Melissa , Makhatadze George I. , Cramer Steven M. 
Published: August 2008

AbstractA library of cold shock protein B (CspB) mutant variants was employed to study protein binding affinity and preferred orientations in cation exchange chromatography. Single site mutations introduced at charged amino acids on the protein surface resulted in a homologous protein set with varying charge density and distribution. The retention times of the mutants varied significantly during linear gradient chromatography. While the expected trends were observed with increasing or decreasing positive charge on the protein surface, the degree of change was a strong function of the location and microenvironment of the mutated amino acid. Quantitative structure–property relationship (QSPR) models were generated using a support vector regression technique that was able to give good predictions of the retention times of the various mutants. Molecular descriptors selected during model generation were used to elucidate the factors affecting protein retention. Electrostatic potential maps were also employed to provide insight into the effects of protein surface topography, charge density and charge distribution on protein binding affinity and possible preferred binding orientations. The use of this protein mutant library in concert with the qualitative and quantitative analyses presented in the article provides an improved understanding of protein behavior in ion exchange systems. Biotechnol. Bioeng. 2009; 102: 869–881. © 2008 Wiley Periodicals, Inc.
Simplified Free‐Radical Reaction Kinetics for p‐Xylene Oxidation to Terephthalic Acid
Authors: Sun W. , Pan Y. , Zhao L. , Zhou X. 
Published: August 2008

AbstractThe kinetic models based on complex free‐radical mechanisms always involve lots of parameters, which result in model overparameterization. In this work, on the basis of free‐radical reaction mechanisms, a simplified kinetics for liquid‐phase catalytic oxidation of p‐xylene (PX) to terephthalic acid (TPA) was developed. By assuming that different peroxy radicals have equivalent reactivity, all the initiation rate constants are identical, and the differences in the rates of termination between various peroxy radicals are neglected, the kinetic model is simplified to include only six parameters that are to be determined by experiment. The kinetic model established in this paper was shown to have satisfactory precision in predicting the concentration profiles. The kinetic model proposed is even simpler than the first‐order kinetic model because the rate constants concerning chain propagation and termination are independent of temperature within the range investigated.
Assignment of the absolute configuration of zwitterionic and neutral macropodumines by means of TDDFT CD calculations
Authors: Guo Yue‐Wei , Kurtán Tibor , Krohn Karsten , Pescitelli Gennaro , Zhang Wen 
Published: August 2008

AbstractMacropodumines B and C (1, 2) are fused pentacyclic alkaloids previously isolated from the Chinese medicinal plant Daphniphyllum macropodum. Macropodumine B (1) possesses an amazing structural feature of a cyclopentadienyl carbanion, stabilized as a zwitterion by an internal iminium cation, which was confirmed by X‐ray diffraction analysis. On the basis of the X‐ray geometry, the absolute configuration of 1 was determined by employing the solid‐state CD/TDDFT approach. The absolute configuration of 2 was instead determined by using TDDFT CD calculations on DFT‐optimized geometries, in comparison with CD spectra recorded in solution. Chirality, 2008. © 2009 Wiley‐Liss, Inc.
Ultrastructural localization of extranuclear progestin receptors in the rat hippocampal formation
Authors: Waters Elizabeth M. , Torres‐Reveron Annelyn , MCewen Bruce S. , Milner Teresa A. 
Published: August 2008

AbstractProgesterone's effects on hippocampus‐dependent behavior and synaptic connectivity maybe mediated through the progestin receptor (PR). Although estrogen induces PR mRNA and cytosolic PR in the hippocampus, nuclear PR immunoreactivity is undetectable by light microscopy, suggesting that PR is present at extranuclear sites. To determine whether this is the case, we used immunoelectron microscopy to examine PR distribution in the hippocampal formation of proestrus rats. Ultrastructural analysis revealed that PR labeling is present in extranuclear profiles throughout the CA1 and CA3 regions and dentate gyrus, and, in contrast to light microscopic findings, in nuclei of a few pyramidal and subgranular zone cells. Most neuronal PR labeling is extranuclear and is divided between pre‐ and postsynaptic compartments; approximately 30% of labeled profiles were axon terminals and 30% were dendrites and dendritic spines. In most laminae, except in CA3 stratum lucidum, about 15% of PR‐immunoreactive profiles were unmyelinated axons. In stratum lucidum, where the mossy fiber axons course, more than 50% of PR‐labeled profiles were axonal. The remaining 25% of PR‐labeled profiles were glia, some resembling astrocytes. PR labeling is strongly dependent on estrogen priming, insofar as few PR‐labeled profiles were detected in ovariectomized, oil‐replaced females. Synapses formed by PR‐labeled terminals were predominantly asymmetric, consistent with a role for progesterone in directly regulating excitatory transmission. These findings suggest that some of progesterone's actions in the hippocampal formation may be mediated by direct and rapid actions on extranuclear PRs and that PRs are well positioned to regulate progesterone‐induced changes at synapses. J. Comp. Neurol. 511:34–46, 2008. © 2008 Wiley‐Liss, Inc.
A compact dynamic channel assignment scheme based on Hopfield networks for cellular radio systems
Authors: Dang A. , Zhu S. 
Published: August 2008

AbstractIn this paper, a new channel assignment strategy named compact dynamic channel assignment (CDCA) is proposed. The CDCA differs from other strategies by consistently keeping the system in the utmost optimal state, and thus the scheme allows to determine a call succeeding or failing by local information instead of that of the whole network. It employs Hopfield neural networks for optimization which avoids the complicated assessment of channel compactness and guarantees optimum solutions for every assignment. A scheme based on Hopfield neural network is considered before; however, unlike others, in this algorithm an energy function is derived in such a way that for a neuron, the more a channel is currently being allocated in other cells, the more excitation the neuron will acquire, so as to guarantee each cluster using channels as few as possible. Performance measures in terms of the blocking probability, convergence rate and convergence time are obtained to assess the viability of the proposed scheme. Results presented show that the approach significantly reduces stringent requirements of searching space and convergence time. The algorithm is simple and straightforward, hence the efficient algorithm makes the real‐time implementation of channel assignment based on neural network feasibility. Copyright © 2008 John Wiley & Sons, Ltd.
Neuronal and glial alterations in the cerebellar cortex of maternally deprived rats: Gender differences and modulatory effects of two inhibitors of endocannabinoid inactivation
Authors: López‐Gallardo M. , Llorente R. , Llorente‐Berzal A. , Marco E.M. , Prada C. , Di Marzo V. , Viveros M.P. 
Published: August 2008

AbstractAdult animals submitted to a single prolonged episode of maternal deprivation (MD) [24 h, postnatal day 9–10] show behavioral alterations that resemble specific symptoms of schizophrenia. Accordingly, this experimental procedure has been proposed as an animal model of schizophrenia based on the neurodevelopmental hypothesis. We have recently reported that MD‐induced sex‐dependent alterations in the hippocampus of neonatal rats. In view of recent evidence for important implications of the cerebellum in neurodevelopmental psychiatric diseases, we have now addressed possible degenerative changes in the cerebellar cortex of neonatal Wistar rats of both genders. To evaluate the presence of degenerated nerve cells, we used Fluoro‐Jade C staining and for the study of astrocytes, we employed glial fibrillary acidic protein. Further, we analyzed the modulatory actions of two inhibitors of endocannabinoids inactivation, the fatty acid amide hydrolase inhibitor N‐arachidonoyl‐serotonin, AA‐5‐HT, and the endocannabinoid reuptake inhibitor, OMDM‐2 (daily subcutaneous injections during the postnatal period 7–12). The animals were sacrificed at postnatal Day 13. MD induced significant increases in the number of Fluoro‐Jade C positive cells (indicative of degenerating neurons) and in the number of glial fibrillary acidic protein positive cells, only in males. The two cannabinoid compounds reversed or attenuated these effects. The present results provide new insights regarding the psycopathological implications of the cerebellum, the role of the endocannabinoid system in neural development, and the possible neurodevelopmental basis of gender differences in schizophrenia. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
The Detection of PHIP Effects Allows New Insights into the Mechanism of Olefin Isomerisation during Catalytic Hydrogenation
Authors: Viale Alessandra , Santelia Daniela , Napolitano Roberta , Gobetto Roberto , Dastrù Walter , Aime Silvio 
Published: August 2008

AbstractPHIP (parahydrogen‐induced polarisation) effects in the 1H NMR spectra of the products of Rh‐complex‐catalysed alkyne hydrogenation brings to light the fact that the cis–trans isomerisation of the formed olefin occurs through the formation of a σ‐bonded intermediate stabilised by the reversible addition of a hydrogen molecule at the metal centre. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Characterization of NiII and PdII Complexes Bearing N,N,S Tridentate Ligands and Their Catalytic Properties for Norbornene Polymerization
Authors: Long Jieming , Gao Haiyang , Song Keming , Liu Fengshou , Hu Hao , Zhang Ling , Zhu Fangming , Wu Qing 
Published: August 2008

AbstractA series of new N,N,S tridentate nickel(II) complexes [(ArN = CHC6H4NPh‐2‐SPh)NiBr] (Ar = 2,6‐diisopropylphenyl, 1; Ar = 2,6‐dimethylphenyl, 2; Ar = Ph, 3) and palladium(II) complexes [(ArN = CHC6H4NPh‐2‐SPh)PdCH3] (Ar = 2,6‐diisopropylphenyl, 4; Ar = 2,6‐dimethylphenyl, 5; Ar = Ph, 6) were synthesized and characterized. X‐ray diffraction analyses of the single‐crystal structures revealed that tridentate complexes 1, 2, 4, 5, and 6 featured a distorted square‐planar coordination of the central metal. Compared to the bidentate metal complexes bearing anilido–imine ligands, the N,N,S tridentate metal complexes showed better stability. In the presence of methylaluminoxane (MAO), nickel complexes 1–3 showed moderate activity toward ethylene oligomerization at atmosphere pressure, but the palladium complexes were inactive. However, the nickel complexes exhibited high activity up to 8.20 × 106 g/(mol of Ni) h and palladium complexes showed very high activity up to 2.68 × 108 g/(mol of Pd) h toward norbornene polymerization with MAO as cocatalyst. The obtained polynorbornenes are vinylic addition polymers with high molecular weights. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Open Problems in Chemical Topology
Authors: Fenlon Edward E. 
Published: August 2008

AbstractThe historical origins of chemical topology are highlighted and seven open problems in the discipline are defined. The current state of experimental work towards their solutions is reviewed. Open problems discussed include size and tightness limits on molecular knots, synthesis of knots more complex than the trefoil, measurement of the enantiomerization barrier of a topological rubber glove, and syntheses of a polyethylene trefoil knot, a stable open knot with stoppers, and a molecular Whitehead link.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)