bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcriptional profiling of brain‐derived‐neurotrophic factor‐induced neuronal plasticity: A novel role for nociceptin in hippocampal neurite outgrowth
Authors: Ring Robert H. , Alder Janet , Fennell Myles , Kouranova Evguenia , Black Ira B. , Thakker‐Varia Smita 
Published: January 2006

AbstractBrain derived neurotrophic factor (BDNF) exhibits a sequence of actions on neurons ranging from acute enhancement of transmission to long‐term promotion of neurite outgrowth and synaptogenesis associated with learning and memory. The manifold effects of BDNF on neuronal modifications may be mediated by genomic alterations. We previously found that BDNF treatment acutely increases transcription of the synaptic vesicle proteinRab3A, required for trophin‐induced synaptic plasticity, as well as the peptideVGF, which increases during learning. To elucidate comprehensive transcriptional programs associated with short‐ and long‐term BDNF exposure, we now examine mRNA abundance and complexity using Affymetrix GeneChips in cultured hippocampal neurons. Consistent with the modulation of synaptic plasticity, BDNF treatment (3–6 h) induced mRNAs encoding the synapse‐associated proteinssynaptojanin 2, neuronal pentraxin 1, septin 9,andryanodine receptor 2. BDNF also induced expression of mRNAs encoding neuropeptides (6–12 h), includingprepronociceptin, neuropeptide Y,andsecretogranin.To determine whether these neuropeptides induced by BDNF mediate neuronal development, we examined their effects on hippocampal neurons. The four mature peptides derived from post‐translational processing of the ppNociceptin propeptide induced the expression of severalimmediate early genesin hippocampal cultures, indicating neuronal activation. To examine the significance of activation, the effects of nociceptin (orphanin FQ) and nocistatin on neurite outgrowth were examined. Quantitative morphometric analysis revealed that nociceptin significantly increased both average neurite length and average number of neurites per neuron, while nocistatin had no effect on these parameters. These results reveal a novel role for nociceptin and suggest that these neuropeptide systems may contribute to the regulation of neuronal function by BDNF. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Severe deficits in 5‐HT2A‐mediated neurotransmission in BDNF conditional mutant mice
Authors: Rios Maribel , Lambe Evelyn K. , Liu Rongjian , Teillon Sarah , Liu JinHong , Akbarian Schahram , Roffler‐Tarlov Suzanne , Jaenisch Rudolf , Aghajanian George K. 
Published: January 2006

AbstractBDNF is thought to provide critical trophic support for serotonin neurons. In order to determine postnatal effects of BDNF on the serotonin system, we examined a line of conditional mutant mice that have normal brain content of BDNF during prenatal development but later depletion of this neurotrophin in the postnatal period. These mice show a behavioral phenotype that suggests serotonin dysregulation. However, as shown here, the presynaptic serotonin system in the adult conditional mutant mice appeared surprisingly normal from histological, biochemical, and electrophysiological perspectives. By contrast, a dramatic and unexpected postsynaptic 5‐HT2A deficit in the mutant mice was found. Electrophysiologically, serotonin neurons appeared near normal except, most notably, for an almost complete absence of expected 5‐HT2A‐mediated glutamate and GABA postsynaptic potentials normally displayed by these neurons. Further analysis showed that BDNF mutants had much reduced 5‐HT2A receptor protein in dorsal raphe nucleus and a similar deficit in prefrontal cortex, a region that normally shows a high level of 5‐HT2A receptor expression. Recordings in prefrontal slice showed a marked deficit in 5‐HT2A‐mediated excitatory postsynaptic currents, similar to that seen in the dorsal raphe. These findings suggest that postnatal levels of BDNF play a relatively limited role in maintaining presynaptic aspects of the serotonin system and a much greater role in maintaining postsynaptic 5‐HT2A and possibly other receptors than previously suspected. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Numerical computations of fundamental eigenstates for the Schrödinger operator under constant magnetic field
Authors: Alouges François , Bonnaillie‐Noël Virginie 
Published: January 2006

AbstractMotivated by questions arising in the theory of superconductivity, we are interested in the study of the fundamental state of the Schrödinger operator with magnetic field in a domain with corners. Although this problem has been extensively studied theoretically, many fewer articles deal with numerical approaches. In this article, we propose numerical experiments based on the finite element method to determine the bottom of the spectrum of the operator. Analyzing the drawbacks of a standard method and the properties of the operator, we propose a natural gauge‐invariant method and provide a few numerical simulations. We furthermore improve the numerical results by coupling the method with a mesh‐refinement technique based on a posteriori error estimates developed by one of the authors. This allows us to look at the monotonicity of the smallest eigenvalue in an angular sector with respect to the angle, which complement theoretical studies. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006
Comparison of V‐cycle multigrid method for cell‐centered finite difference on triangular meshes
Authors: Kwak Do Y. , Lee Jun S. 
Published: January 2006

AbstractWe consider a multigrid algorithm (MG) for the cell centered finite difference scheme (CCFD) on general triangular meshes using a new prolongation operator. This prolongation is designed to solve the diffusion equation with strongly discontinuous coefficient as well as with smooth one. We compare our new prolongation with the natural injection and the weighted operator in Kwak, Kwon, and Lee (Appl Math Comput 21 (1999), 552–564) and the behaviors of these three prolongation are discussed. Numerical experiments show that (i) for smooth problems, the multigrid with our new prolongation is fastest, the next is the weighted prolongation, and the third is the natural injection; and (ii) for nonsmooth problems, our new prolongation is again fastest, the next is the natural injection, and the third is the weighted prolongation. In conclusion, our new prolongation works better than the natural injection and the weighted operator for both smooth and nonsmooth problems. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006
Finite‐difference approximation for the u(k)‐derivative with O(hM−k+1) accuracy: An analytical expression
Authors: Dubovsky Vadim , Yakhot Alexander 
Published: January 2006

AbstractAn approximation of function u(x) as a Taylor series expansion about a point x0 at M points xi, ∼ i = 1,2,…,M is used where xi are arbitrary‐spaced. This approximation is a linear system for the derivatives u(k) with an arbitrary accuracy. An analytical expression for the inverse matrix A−1 where A = [Aik] = ${1\over k!}$(xi − x0)k is found. A finite‐difference approximation of derivatives u(k) of a given function u(x) at point x0 is derived in terms of the values u(xi). © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006
Direct patterning of poly(amic acid) and low‐temperature imidization using a photo‐base generator
Authors: Fukukawa Ken‐ichi , Shibasaki Yuji , Ueda Mitsuru 
Published: January 2006

AbstractA negative‐type photosensitive polyimide (PSPI) based on poly(amic acid) (PAA) and a photo‐base generator (PBG) has been developed. PAA‐2, the polyimide precursor, was prepared from oxydianiline (ODA) and 4,4′‐biphthalic dianhydride (BPDA) in N,N‐dimethylacetamide (DMAc), and used directly for lithographic evaluations. Since a photo‐generated base, dimethyl piperidine (DMP), was effective for the imidization of PAA‐2 to the corresponding PI‐2 at temperatures up to 200°C, the dissolution behavior of this system was studied in relation to PBG content, bake‐temperature dependence, and composition of the aqueous alkaline developer. The PSPI using 85 wt% PAA‐2 and 15 wt% synthesized PBG showed a sensitivity of 220 mJ/cm2 and contrast of 11.7 when exposed to 365‐nm light (i‐line) and developed with an aqueous alkaline developer (aqueous tetramethylammonium hydroxide and iso‐propanol, TMAHaq/iPrOH). A clear negative image with 8‐µm features was produced by contact‐printing and converted into the PI‐2 pattern upon heating at 200°C, confirming the results obtained by Scanning electro microscopy (SEM) imaging and infrared spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd.
Electrocatalytic reduction of oxygen at platinum particles photodeposited on polyaniline/Nafion film
Authors: Yang Qinghao , Wang Yangyong , Nakano Hiroyuki , Kuwabata Susumu 
Published: January 2006

AbstractPlatinum based electrocatalyst for oxygen reduction reaction was prepared by photodeposition of platinum (Pt) particles on the surface of polyaniline/Nafion (PANI/Nafion) composite film. Polyaniline (PANI) acts as a convenient catalyst for the photodeposition of Pt particles and thus gives extremely low platinum loading, from 3 to 32 µg/cm2, on the surface of the PANI/Nafion composite film. Normal cyclic voltammetry (CV) studies were carried out to investigate the influence of different photodeposition conditions. Rotating disc electrodes (RDEs) were used to affirm the oxygen reduction mechanism of these catalytic membranes. Parameters such as the total transferred electrons, limiting reduction current density were determined by Koutecky–Levich analysis of the RDE results. Copyright © 2006 John Wiley & Sons, Ltd.
“Smart” silica‐rubber nanocomposites in virtue of hydrogen bonding interaction
Authors: Peng Chih‐Cheng , Göpfert Astrid , Drechsler Markus , Abetz Volker 
Published: January 2006

AbstractIn this paper “smart” nanocomposites comprising Stöber silica nanoparticles of two different surface polarities and a novel thermoreversible crosslinking rubber carrying self‐complementary hydrogen bonding (HB) moiety were presented. This strategy is based on the idea that the introduction of HB between silica and the modified rubber improves both the filler–rubber interaction and the mechanical properties. The resulting nanocomposites were mainly characterized using transmission electron microscopy (TEM) and dynamic mechanical analysis. It is found that the competition and symbiosis between the filler–filler, filler–rubber and rubber–rubber HB interaction, as well as the dynamic mechanical properties were controllable simply by changing the silica loading, the degree of rubber modification and the temperature. Besides, the TEM micrographs showed that the modifications of both silica nanoparticles and rubber promoted better silica dispersion in the rubber matrix. By this strategy it is evident that the Payne effect was reduced and it is possible to modify the mechanical properties of such silica filled composites in a controlled way, which could, as an example, meet the requirements for tire applications. Copyright © 2006 John Wiley & Sons, Ltd.
Preparation of aqueous anionic poly(urethane‐urea) dispersions. Influence of the incorporation of acrylic, polycarbonate and perfluoro‐oligoether diols on the dispersion and polymer properties
Authors: Durrieu Vanessa , Gandini Alessandro 
Published: January 2006

AbstractAqueous poly(urethane‐urea) dispersions were prepared by the prepolymer mixing technique, without using any organic solvent. This work focused on the incorporation into the prepolymer chain of specific macrodiols bearing acrylic, polycarbonate and perfluoro‐oligoether chains, in conjunction with a poly(propylene oxide) diol (Mn = 1000). All the dispersions were synthesized with a fixed NCO/OH ratio, using α,α,α′,α′‐tetramethyl‐1,3‐xylylene diisocayanate, a fixed proportion of emulsifying agent (dimethylol propionic acid, neutralized with triethylamine) and the same chain extender (1,2‐ethylene diamine). The properties of both the dispersions and the dried polymer films were characterized as a function of the nature of the specific incorporated diol and its proportion in the polymer chain, in order to establish criteria leading to an optimized performance in terms of particle size, viscosity, and polymer film properties. Copyright © 2006 John Wiley & Sons, Ltd.
Reactions of fluoroalkanoyl peroxides with single‐walled carbon nanotubes: application to sidewall modification of single‐walled carbon nanotubes with the introduction of fluoroalkyl groups
Authors: Sawada Hideo , Shindo Kaoru , Ueno Katsuya , Hamazaki Kazuo 
Published: January 2006

AbstractFluoroalkanoyl peroxides reacted with single‐walled carbon nanotubes (SW‐CNTs) to afford fluoroalkylated SW‐CNT derivatives under very mild conditions. Fluoroalkylated SW‐CNT derivatives [RF‐(SW‐CNT)s] thus obtained exhibited no solubility in aqueous and traditional organic media; however, RF‐(SW‐CNT)s were solubilized into water more effectively than the parent SW‐CNT by the use of fluoroalkyl end‐capped homooligomers. However, fluroalkyl end‐capped SW‐CNT cooligomers were obtained by the reactions of fluroalkanoyl peroxides with SW‐CNTs in the presence of radical polymerizable monomers, and these fluoralkylated SW‐CNT cooligomers were found to exhibit a good solubility in aqueous and organic media. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of end group polarity and molecular weight on the lower critical solution temperature of poly(N‐isopropylacrylamide)
Authors: Furyk Steven , Zhang Yanjie , Ortiz‐Acosta Denisse , Cremer Paul S. , Bergbreiter David E. 
Published: January 2006

AbstractThe lower critical solution temperatures (LCSTs) for mass fractionated samples of poly(N‐isopropylacrylamide) (PNIPAM) were studied to determine the effect of polymer molecular weight on the LCST using a high throughput temperature gradient apparatus. PNIPAM fractions prepared by a conventional radical polymerization using azoisobutyronitrile (AIBN) as the initiator had LCSTs that were largely invariant with molecular weight or dispersity. Only slight deviations were noted with lower molecular weight samples. An 18‐kDa sample had a 0.6 °C higher LCST. A 56‐kDa sample had a 0.2 °C higher LCST. PNIPAM derivatives prepared with a triphenylmethyl (trityl) functionalized azo initiator were also prepared and mass fractionated. These samples' LCSTs were identical to those of PNIPAM samples prepared using AIBN initiation when higher molecular weight samples were compared. The trityl‐containing PNIPAM fractions' LCSTs varied when the molecular weight decreased below 100 kDa. Acidolysis of the trityl end groups provided a third set of PNIPAM derivatives whose LCST differed only with samples with Mw values < 60 kDa. These results show there is no effect of molecular weight on LCST until the degree of polymerization is such that end group structure becomes significant. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1492–1501, 2006
Reactivity of styrene and substituted styrenes in the presence of a homogeneous isospecific titanium catalyst
Authors: De Carlo Francesco , Capacchione Carmine , Schiavo Vincenzo , Proto Antonio 
Published: January 2006

AbstractThe isospecific polymerization of several para‐substituted styrenes was performed in the presence of the catalyst dichloro[1,4‐dithiabutanediyl‐2,2′‐bis(4,6‐di‐tert‐butyl‐phenoxy)]titanium activated by methylaluminoxane. All the polymers were highly regioregular and isotactic with narrow molecular weight distributions. The presence of electron‐donating substituents on the aromatic ring had a positive effect on the catalyst activity, whereas electron‐withdrawing substituents affected the polymerization activity negatively. Binary copolymerizations of the various substituted styrenes showed an inversion of the reactivity with respect to that observed in the homopolymerization. These results suggested that the last monomer unit of the polymer chain coordinated to the metal center, influencing the reactivity of the catalyst with respect to the incoming monomer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1486–1491, 2006
Liquid‐like structure of polymer solutions near the overlap concentration
Authors: Francis R. S. , Patterson G. D. , Kim S. H. 
Published: January 2006

AbstractThe light scattering structure factor S(q, c) has been measured for a series of concentrations near the overlap value c* for solutions of high molecular weight poly(α‐methyl styrene) in the good solvent toluene. Scattering functions near and above overlap are characterized by a maximum as a function of scattering vector q. Scattering functions have also been calculated for these conditions using the measured second virial coefficient and radius of gyration, as reported previously for dilute solutions. The scattering function is factored into an intramolecular part that is described by a Debye function with no adjustable parameters and an intermolecular part that depends on the coil–coil pair correlation function, as suggested by Flory and Bueche. The pair correlation function is calculated using the Percus–Yevick theory of liquids and the Flory–Krigbaum potential for coil–coil interactions, as suggested by Frank Stillinger. Good agreement is obtained for the most concentrated dilute solutions, but as the overlap concentration is approached significant discrepancies are observed. The thermodynamic value of the scattering function, S(0, c), is overestimated by the theory. This discrepancy is discussed in terms of the importance of three‐body interactions, the failure of the Flory–Krigbaum potential in semidilute solutions and the limited precision of the standard protocol for calculating the measured scattering function in nondilute solutions. The observed maximum in the scattering function near overlap is not quantitatively reproduced by the theory. This discrepancy is discussed in terms of the failure of the shape of the Flory–Krigbaum potential to accurately reflect the energy of overlap for chains separated by distances near twice the radius of gyration. The mean‐field nature of the potential ignores the increased probability of interactions of linear neighboring segments. Well into the overlap region, the calculated scattering function poorly describes the observed results. The failure of the Flory–Bueche approximation in semidilute solutions is discussed as well as the effect of a changing radius of gyration as a function of concentration on the intramolecular scattering function. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 703–710, 2006
Investigating chemical process accidents: Examples of good practices
Authors: Morrison D.R. , Ogle R.A. , Viz M.J. , Carpenter A.R. , Su Y. 
Published: January 2006

AbstractThe accident investigation process, rooted in the scientific method, relies heavily on the use of evidence. This paper reviews aspects of the investigation process for three large‐scale chemical process unit accidents (explosions or fires) with a focus on evidence: its collection, handling, use, and analysis. Real incidents provide challenges to the investigation process; some of these challenges involve questions surrounding evidence, such as when is evidence collection complete and how do we know that certain nonphysical evidence (such as witness statements) is reliable? These case studies provide practical examples of the importance of following good engineering practices throughout the life cycle of the investigation with respect to evidence.The objective of an accident investigation is to determine what happened so that a recurrence of the accident can be prevented. The investigator of a chemical plant accident is confronted with numerous challenges to the fact‐finding process because the accident has destroyed or altered significant sources of evidence such as the physical equipment and the process data. The investigator must often cope with incomplete or contradictory data. The best strategy for dealing with these difficulties is the scientific method: gather facts from numerous independent sources, develop and test alternative hypotheses, and evaluate potential causal factors using sound engineering and scientific principles. The ability to ultimately identify the root causes of a complex chemical plant accident depends heavily on the quality and comprehensiveness of the fact‐finding process. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006
Nitridation and reoxidation of high‐k metal oxide thin films using argon excimer sources
Authors: Yu J. J. , Boyd I. W. 
Published: January 2006

AbstractWe report for the first time the nitridation and reoxidation of metal oxide films with the active nitrogen and oxygen species produced by argon excimer sources. Preliminary results on 9 nm Ta2O5 films using this method exhibited excellent electrical properties with the leakage current density being up to 3 orders of magnitude lower than the as‐deposited films. Breakdown fields were found to be greater than 13 MV/cm. Accumulation capacitance with the nitrided film increased by 25% compared with the as‐deposited film. Optical transmittance was as high as 99% in the visible region and more than 74% in the UV region. The refractive index at 632.8 nm was high up to 2.2. The Ar excimer source emitted energetic VUV photons which could break nitrogen triple bonds to produce active nitrogen species and photodissociate O2 to form strong oxidant O3 and highly reactive O (1S) atoms, leading to the nitridation and reoxidation of Ta2O5 without the need for the use of H2O, NH3 and high temperature substrate heating. The nitridation process for a specific film thickness can be optimised by adjusting the VUV irradiation time to achieve increased accumulation capacitance and improved leakage property simultaneously. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and Characterization of Iron Oxide Nanorods/Nanobelts Prepared by a Simple Iron–Water Reaction
Authors: Zhao Yi Min , Li Yan‐Hui , Ma Ren Zhi , Roe Martin J. , McCartney David G. , Zhu Yan Qiu 
Published: January 2006

AbstractSingle‐crystalline hexagonal α‐Fe2O3 nanorods/nanobelts have been created by a simple iron–water reaction in the low‐temperature range of 350–450 °C. Scanning electron microscopy examination shows that the needle‐like products, radiating from and perpendicular to the original large iron particle surfaces, are up to a few micrometers in length with an average diameter from 20 nm (tip) to 100 nm (base). X‐ray photoelectron spectroscopy and FTIR spectroscopy reveal that the outermost surface of the nanorods consists of Fe2O3 without organic impurity contaminants, which could possibly result from other methods, such as hydrothermal growth. Nanobelt‐like structures are believed to result from a combination of increased reaction temperature and time. The initial formation and subsequent growth of α‐Fe2O3 nanorods may be explained by the iron metal corrosion mechanism.
An integrated approach to customer elicitation for the aerospace sector
Authors: Guenov Marin D. , Barker Stephen G. , Hunter Chris , Horsfield Ian , Coleridge‐Smith Neil 
Published: January 2006

AbstractAn integrated approach, the Transitional Business Model (TBM), is proposed, to facilitate rapid and proactive response to customer enquiries, and to inform the derivation, development, and promotion of new and innovative concepts. The model fulfils a need identified within the aerospace sector to enhance the ability for rapid customer needs elicitation, and to improve competitiveness. This paper presents the results of collaborative research with a major aerospace organization culminating in the development of a prototype © 2006 Wiley Periodicals, Inc. Syst Eng 9: 62–72, 2006