bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of ionic polyurethanes with pyrene rings: Spectral properties and fluorescence quenching study
Authors: Buruiana Emil C. , Buruiana Tinca , Strat Georgeta , Strat Mitachi 
Published: July 2005

AbstractHydrophilic ionic polyurethanes with 4‐chloromethylphenylcarbamoyl‐1‐oxymethylpyrene located on the quaternary ammonium structure from a polymer based on poly(ethylene glycol), isophorone diisocyanate, and N‐methyldiethanolamine were prepared by a quaternization reaction, in which the amount of pyrene covalently attached to the polymeric backbone ranged from 1.14 to 19.82 mmol of fluorophore/100 g of polymer. It was interesting to compare the photoluminescence of the pyrene polyurethane carrying a few mole percent of pyrene moieties with that of a third polymer resulting from its subsequent quaternization with benzyl chloride up to a concentration of ionic groups as in the latter (quaternization degree = 14.15%). The process of excimer formation between the pyrene molecules attached to the ionic polyurethane was investigated in tetrahydrofuran (THF), dimethylformamide, film, and THF/H2O to illustrate the expected differences in the polymer behavior compared with that of the starting pyrene derivative. The formation of aggregates or core–shell micelles was sustained by the fluorescence data, which indicated the existence of pyrene units in the ground state of the molecule, giving rise thus to an explanation for the high excimer‐to‐monomer intensity ratio. The fluorescence decay of pyrene polyurethanes in the presence of various concentrations of nitrobenzene used as a quencher was analyzed too when the fluorescence quenching in the polymer solution normally followed Stern–Volmer kinetics. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3945–3956, 2005
Polymerization of n‐phenyl maleimide by lanthanide complexes
Authors: Zhao Bei , Wang Yaorong , Lu Chengrong , Shen Qi , Deng Mingyu 
Published: July 2005

AbstractN‐Phenyl maleimide (N‐PMI) was successfully polymerized by divalent rare‐earth complexes (ArO)2Sm(THF)4 (ArO = 2,6‐di‐tert‐butyl‐4‐methyl phenoxo‐; THF = tetrahydrofuran) and (Ar′O)2Ln(THF)3 (Ar′O = 2,6‐di‐tert‐butyl phenoxo‐; Ln = Sm, Yb, or Eu). The central metals greatly affected the reactivity, and the reactivity order was Sm(II) > Yb(II) > Eu(II). The activity of (Ar′O)2Sm(THF)3 was higher than that of (ArO)2Sm(THF)4. The polymerization yields were higher in THF than in other solvents, and the maximum yields were obtained around 25 °C. A proposed mechanism is discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3966–3972, 2005
Posttraumatic growth in prostate cancer survivors and their partners
Authors: Thornton Andrea A. , Perez Martin A. 
Published: July 2005

AbstractWe examined posttraumatic growth (PTG) in men treated for prostate cancer and their partners 1 year after surgery. Levels of PTG in prostate cancer survivors and their partners were similar and modest. For survivors, higher levels of presurgery negative affect, and coping by using positive reframing and emotional support were associated with higher levels of PTG 1 year following surgery. For partners, PTG 1 year after the patient's surgery was higher in partners who were partnered to employed patients, were less educated, endorsed higher cancer‐specific avoidance symptoms of stress at presurgery, and used positive reframing coping. Quality of life was largely unrelated to PTG in survivors or partners. Findings suggest that psychological disruption associated with the cancer experience and coping are related to PTG in prostate cancer survivors and their partners. Copyright © 2005 John Wiley & Sons, Ltd.
Study on mechanism of soft magnetic properties for high‐frequency application in Ni75Fe25–SiO2 granular films
Authors: Ge Shihui , Yang Xiaolin , Youn Kim Kwang , Xi Li , Kou Xiaoming , Yao Dongsheng , Li Binsheng , Wang Xinwei 
Published: July 2005

AbstractExcellent soft magnetic properties have been achieved in a wide metal volume fraction (x) range for as‐deposited (Ni75Fe25)x–(SiO2)(1–x) granular films fabricated by magnetron sputtering. With x changes from 0.81 to 0.52, the films exhibit small coercivity (Hc) not exceeding 5 Oe and high electrical resistivity ρ. The minimum Hc value of 87.6 A m–1 was obtained for the sample of x = 0.81. At the frequency lower than 550 MHz, the real part μ′ of complex permeability keeps about 170 and the image part μ″ is less than 26. Especially, for the film with very low x (= 0.52), besides the low Hc (∼3 Oe), very high ρ over 1.18 × 104 μΩ cm has been obtained. A combined study of TEM and XRD indicates that the samples consist of Ni75Fe25 particles uniformly embedded in insulating SiO2 matrix. The excellent soft magnetic property is ascribed to the exchange coupling among magnetic particles due to the long exchange length of Ni75Fe25. The investigation of the Henkel plot evidences the existence of this intergranular interaction. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and magnetic properties of TbCo7–xMx
Authors: Guo Yongquan , Feng Weicun , Luo Jun , Liang Jingkui , Yu Xiaojun , Li Wei 
Published: July 2005

AbstractA novel intermetallic compound, TbCo7–xMx (M = 3d transition metal or normal metal), has been successfully synthesized. TbCo7–xMx crystallizes in a hexagonal TbCu7 structure with space group of P6/mmm. According to the structural refinement, the M dopants occupy the 2e and 3g crystal positions based on their electronegativities. TbCo7–xMx exhibits ferromagnetic order. The saturation moment has been calculated with a corrected magnetic valence model; the calculated results agree well with experiment. The correction to the structural stability model of TbCo7–xMx has been discussed in terms of the effective atomic radius ratio and the difference of electronegativity between Tb and (Co, M). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray investigations of nanopowder WO3 thick films
Authors: Khatko V. , Guirado F. , Hubalek J. , Llobet E. , Correig X. 
Published: July 2005

AbstractNanoparticle tungsten trioxide thick films based on commercial WO3 nanopowder and powder mixtures with different concentrations of metals (Ag, In and Bi) were prepared by screen‐printing onto alumina substrates. The changes in phase composition, crystallite size and cell parameters induced in tungsten trioxide thick films by the inclusion of metal impurities were investigated by X‐ray diffraction (XRD). Some of the samples were further analysed using a high temperature XRD method. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phonon modes of monoclinic BiB3O6
Authors: Gössling A. , Möller T. , Stein W.‐D. , Becker P. , Bohatý L. , Grüninger M. 
Published: July 2005

AbstractWe present a detailed study of the phonon modes of the monoclinic compound BiB3O6 based on polarized reflectivity measurements on single crystals.The spectra are analysed by means of a generalized Drude–Lorentz model, which allows us to resolve the modes of A and B symmetry. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional theory of the iron–nitrosyl (S = 3/2) complex
Authors: Cheng Hsiu‐Yao , Chang Shyang 
Published: July 2005

AbstractOn the basis of density functional theory (DFT), the iron–nitrosyl complex Fe[Me3TACN](NO)(N3)2 (S = 3/2) is studied via the B3LYP hybrid method. Its Raman vibrational frequencies, atomic net charges, and spin densities are analyzed. The related complexes Fe(NH3) (n = 1, 2, and 3) are employed as reference compounds to determine the characteristics of the central iron. Our results indicate that the S = 3/2 spin ground state of Fe[Me3TACN](NO)(N3)2 is best described by the presence of FeII (S = 2) anti‐ferromagnetically coupled to NO0 (S = 1/2) yielding FeII[Me3TACN](NO0)(N)2. This is clearly different from the previous FeIII‐NO− theoretical assignment. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Behavior of the Dirichlet boundary for wave functions in a class of singular potentials
Authors: Bandyopadhyay S. K. , Bhattacharyya K. 
Published: July 2005

AbstractVariational studies on spiked oscillators with the potential form x2 + λ/xβ in [0, ∞) reveal certain limitations of the conventional choices for wave functions in the β ≥ 2 regime. A careful analysis shows the necessity of properly incorporating the Dirichlet boundary condition at x = 0. Subsequent pilot calculations on this notion perform nicely, justifying the worth of the endeavor. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Spectral techniques applied to sparse random graphs
Authors: Feige Uriel , Ofek Eran 
Published: July 2005

AbstractWe analyze the eigenvalue gap for the adjacency matrices of sparse random graphs. Let λ1 ≥ … ≥ λn be the eigenvalues of an n‐vertex graph, and let λ = max[λ2,|λn|]. Let c be a large enough constant. For graphs of average degree d = c log n it is well known that λ1 ≥ d, and we show that $\lambda = O(\sqrt{d})$. For d = c it is no longer true that $\lambda = O(\sqrt{d})$, but we show that by removing a small number of vertices of highest degree in G, one gets a graph G′ for which $\lambda = O(\sqrt{d})$. Our proofs are based on the techniques of Friedman Kahn and Szemeredi from STOC 1989, who proved similar results for regular graphs. Our results are useful for extending the analysis of certain heuristics to sparser instances of NP‐hard problems. We illustrate this by removing some unnecessary logarithmic factors in the density of k‐SAT formulas that are refuted by the algorithm of Goerdt and Krivelevich from STACS 2001. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005
Gompertz kinetics model of fast chemical neurotransmission currents
Authors: Easton Dexter M. 
Published: July 2005

AbstractAt a chemical synapse, transmitter molecules ejected from presynaptic terminal(s) bind reversibly with postsynaptic receptors and trigger an increase in channel conductance to specific ions. This paper describes a simple but accurate predictive model for the time course of the synaptic conductance transient, based on Gompertz kinetics. In the model, two simple exponential decay terms set the rates of development and decline of transmitter action. The first, r, triggering conductance activation, is surrogate for the decelerated rate of growth of conductance, G. The second, r′, responsible for Y, deactivation of the conductance, is surrogate for the decelerated rate of decline of transmitter action. Therefore, the differential equation for the net conductance change, g, triggered by the transmitter is dg/dt = g(r−r′). The solution of that equation yields the product of G(t), representing activation, and Y(t), which defines the proportional decline (deactivation) of the current. The model fits, over their full‐time course, published records of macroscopic ionic current associated with fast chemical transmission. The Gompertz model is a convenient and accurate method for routine analysis and comparison of records of synaptic current and putative transmitter time course. A Gompertz fit requiring only three independent rate constants plus initial current appears indistinguishable from a Markov fit using seven rate constants. Synapse 58:53–61, 2005. © 2005 Wiley‐Liss, Inc.
Increased AMPA GluR1 receptor subunit labeling on the plasma membrane of dendrites in the basolateral amygdala of rats self‐administering morphine
Authors: Glass Michael J. , Kruzich Paul J. , Colago Eric E.O. , Kreek Mary Jeanne , Pickel Virginia M. 
Published: July 2005

AbstractGlutamate‐dependent synaptic plasticity is emerging as an important neural substrate of addiction. These drug‐dependent neural adaptations may occur within brain systems that mediate reward, emotion, and cognitive function such as the amygdala complex. Modification of glutamate receptor targeting may be a key mechanism mediating neural plasticity; however, evidence for alteration of amygdala AMPA receptor localization in response to drug self‐administration is lacking. High‐resolution immunogold electron microscopic immunocytochemistry was used to compare surface and intracellular labeling of the calcium sensitive AMPA GluR1 receptor subunit in the basolateral (BLA) and central (CeA) nuclei of the amygdala in rats self‐administering escalating doses of morphine or saline. Morphine self‐administration was associated with regionally diverse effects on dendritic GluR1 targeting in the BLA and CeA. In the BLA of morphine self‐administering animals, there was a significant increase in the proportion of immunogold particles for GluR1 on the plasma membrane of dendrites, particularly in association with extrasynaptic sites, which was most prominent in large (2–4 μm) profiles. In contrast, there were no significant differences in surface or intracellular immunogold labeling in the CeA between morphine self‐administering and control animals. In both amygdala regions, GluR1 and the μ‐opioid receptor, the major cellular target of morphine, were only infrequently colocalized. These results indicate that GluR1 targeting is a dynamic process that can be differentially affected in distinct amygdala regions in response to chronic self‐administration of morphine. Homeostatic adaptations in the subcellular localization of calcium sensitive AMPA receptors within the BLA may be an important neural substrate for alterations in reward, autonomic function, and behavioral processes associated with opiate addiction. Synapse 58:1–12, 2005 © 2005 Wiley‐Liss, Inc.
Expanded mesencephalic precursors develop into grafts of densely packed dopaminergic neurons that reinnervate the surrounding striatum and induce functional responses in the striatal neurons
Authors: Rodriguez‐Pallares J. , Parga J.A. , Rey P. , Guerra M.J. , Labandeira‐Garcia J.L. 
Published: July 2005

AbstractThe search for alternative sources of dopaminergic cells, other than primary fetal tissue for transplantation in Parkinson's disease has become a major focus of research. Different methodological approaches have led to generation in vitro of cells expressing DA‐cell markers, although these cells are frequently unable to survive for a long time in vivo after transplantation and/or induce functional effects in the host brain. In the present study, we grafted cell aggregates treated with antibodies against fibroblast growth factor 4 into dopaminergic‐denervated striata in rats. Furthermore, we grafted cell suspensions from primary mesencephalic fetal tissue. Grafts from expanded precursors were able to survive (at least 3 months postgrafting) and most decreased the lesion‐induced ipsiversive rotation. In addition, immunolabeling for tyrosine hydroxylase and/or Fos showed that the grafts reinnervated the surrounding striatal tissue with dopaminergic terminals, and induced the expression of Fos in the striatal neurons of the reinnervated area after administration of amphetamine to the host rat. The number of dopaminergic cells in grafts from expanded precursors inducing rotational recovery was usually lower (1,226 ± 314) than that in grafts from primary fetal tissue (1,671 ± 122), but they were more densely packed in grafts that were of smaller volume and did not have the characteristic central nondopaminergic area observed in grafts from primary fetal tissue. The results suggest that long‐term survival and functional integration into the DA‐denervated striatum can be achieved with grafts of expanded mesencephalic precursors. Synapse 58:12–21, 2005. © 2005 Wiley‐Liss, Inc.
Dual synaptic sites of D1‐dopaminergic regulation of ethanol sensitivity of NMDA receptors in nucleus accumbens
Authors: Zhang Tao A. , Hendricson Adam W. , Morrisett Richard A. 
Published: July 2005

AbstractRegulation of NMDAreceptor‐mediated synaptic transmission onto accumbal medium spiny neurons (MSN) may constitute an important site in drug reward and reinforcement in mesolimbic structures. Previously, we reported that D1‐like dopamine receptors activate a postsynaptic cAMP/PKA/DARPP‐32 signaling cascade culminating in phosphorylation of SER897‐NR1 subunits and a reduction in the sensitivity to ethanol of NMDA receptor‐mediated synaptic transmission. Here, we use a detailed electrophysiological analysis of D1‐like receptor regulation of the ethanol sensitivity of accumbal NMDA receptors (NMDARs) through recordings of quantal Sr2+‐supported NMDA miniature synaptic currents (mEPSCs) in reduced Mg2+ (0.6 mM) and report dual presynaptic and postsynaptic components of D1‐like regulation of ethanol sensitivity of NMDARs. Ethanol inhibited NMDA mEPSC amplitude and frequency in a dose‐dependent manner (25–75 mM), indicating inhibitory effects on presynaptic and postsynaptic components NMDA receptor‐mediated synaptic transmission. The presynaptic inhibitory effect was corroborated by analysing the ratio of paired‐pulse facilitation (PPF) of Ca2+‐supported NMDA EPSCs. Activation of D1 receptors with the agonist, SKF 38393 (25 μM), reversed ethanol suppression of NMDA mEPSC frequency and amplitude. Furthermore, the Mg2+‐dependent decay off‐rate of NMDA mEPSCs was substantially reduced by ethanol in a manner strongly reversed by the D1 agonist. D1 receptor‐mediated attenuation of both the presynaptic and postsynaptic actions of ethanol was completely blocked by a D1 selective antagonist (SCH 23390). These data suggest that D1‐like receptors modulate both the presynaptic and postsynaptic effects of ethanol on NMDA receptor‐mediated synaptic transmission in nucleus accumbens (NAc) and that these interactions may contribute to ethanol‐induced neuroadaptation of the reward pathway. Synapse 58:29–43, 2005. © 2005 Wiley‐Liss, Inc.
Three decades of in vivo x‐ray fluorescence of lead in bone
Authors: Chettle D. R. 
Published: July 2005

AbstractIn vivo measurements of lead in bone were first made in the early 1970s. Of the three systems that have been used (57Co excited K, 125I or polarized excited L, 109Cd excited K), 109Cd excited K x‐ray fluorescence has been most widely adopted. Bone lead measured in vivo has been shown to reflect cumulative exposure, but the rate of input to bone varies with level of exposure. Chelated lead does not relate directly to bone lead. Endogenous exposure has been highlighted by bone lead measurements and this release of lead from bone and hence the half‐life of lead in bone have been shown to depend on age and on intensity of lead exposure. Thus x‐ray spectrometry has made a significant contribution to the understanding of long‐term human lead metabolism. Copyright © 2005 John Wiley & Sons, Ltd.
A new SR‐TXRF vacuum chamber for ultra‐trace analysis at HASYLAB, Beamline L
Authors: Streli C. , Pepponi G. , Wobrauschek P. , Jokubonis C. , Falkenberg G. , Zaray G. 
Published: July 2005

AbstractA new vacuum chamber for synchrotron radiation‐induced total reflection x‐ray fluorescence (SR‐TXRF) analysis has been installed at HASYLAB, DESY, Hamburg, beamline L utilizing the translation and rotation stages of the regular microfocus setup for adjustment. The chamber is equipped with an automatic sample loader for 30 mm diameter quartz reflectors for inserting the prepared sample reflectors in the measuring position with high reproducibility. Alternatively, a chuck can be inserted allowing various sizes and shapes of samples to be measured. The fluorescence radiation emitted by the sample was measured by a silicon drift detector (SDD) with a 5 mm2 active area and detection limits of 15 fg have been obtained on a sample containing 100 pg of Ni using an Ni/C multilayer monochromator. Using the Si 111 crystal monochromator also x‐ray absorption near edge structure (XANES) investigations in total reflection geometry on trace elements are feasible. Cr K‐edge XANES measurements of C. avellana L. (hazel) pollen (20 ppm Cr concentration) and on an urban aerosol sample are presented. The Cr content in the pollen amounts to about 20 ppm, Detection limits of Cr were found to be 40 pg for a 30 s measuring time, which seems to be reasonable for performing energy scans for x‐ray absorption fine structure measurements. Further, the setup is suitable to perform angle scans to determine depth profiles of implants in Si wafers. This was tested for ultra‐shallow implants of As in Si. Copyright © 2005 John Wiley & Sons, Ltd.
In search of a residual dividend policy
Authors: Baker H. Kent , Smith David M. 
Published: July 2005

AbstractWe survey 309 sample firms exhibiting behavior consistent with a residual dividend policy and their matched counterparts to learn how they set their dividend policies. The findings reveal that the sample firms are more likely than their counterparts to maintain a long‐term dividend payout ratio, use long‐run earnings forecasts in setting the dividend, and be unconcerned about the cost of raising external funds. Yet, firms behaving as though they follow a residual dividend policy generally do not profess to follow the policy. At best, the sample firms follow a “modified” residual policy in which they carefully manage their payout ratio and dividend trend. Although it may not be an explicit goal of such a dividend policy, consistently low free cash flow typically results.
Globalization and portfolio risk over time: The role of exchange rate
Authors: Fooladi Iraj J. , Rumsey John 
Published: July 2005

AbstractWe examine benefits of international diversification for the period 1 January 1988 to 30 June 2000. We introduce a new variable (lambda) that measures these benefits more directly than do the pairwise correlations among equity markets, which are used in most other studies. Our study shows that despite international integrations, the benefits of international diversification measured in USD persist. Using lambda, we provide evidence that the increase in co‐movements between equity market returns (measured in local currencies) has been counterbalanced by movements in exchange rates. We confirm our results by subjecting the trend in lambda to several tests.
A Speleothem Record of Younger Dryas Cooling, Klamath Mountains, Oregon, USA
Authors: Vacco David A. , Clark Peter U. , Mix Alan C. , Cheng Hai , Edwards R. Lawrence 
Published: July 2005

AbstractA well-dated δ18O record in a stalagmite from a cave in the Klamath Mountains, Oregon, with a sampling interval of 50 yr, indicates that the climate of this region cooled essentially synchronously with Younger Dryas climate change elsewhere in the Northern Hemisphere. The δ18O record also indicates significant century-scale temperature variability during the early Holocene. The δ13C record suggests increasing biomass over the cave through the last deglaciation, with century-scale variability but with little detectable response of vegetation to Younger Dryas cooling.
A path-transformation for random walks and the Robinson-Schensted correspondence
Authors: O’Connell Neil 
Published: July 2005

The author and Marc Yor recently introduced a path-transformationG(k)G^{(k)}with the property that, forXXbelonging to a certain class of random walks onZ+k\mathbb {Z}_+^k, the transformed walkG(k)(X)G^{(k)}(X)has the same law as the original walk conditioned never to exit the Weyl chamber{x: x1≤⋯≤xk}\{x:\ x_1\le \cdots \le x_k\}. In this paper, we show thatG(k)G^{(k)}is closely related to the Robinson-Schensted algorithm, and use this connection to give a new proof of the above representation theorem. The new proof is valid for a larger class of random walks and yields additional information about the joint law ofXXandG(k)(X)G^{(k)}(X). The corresponding results for the Brownian model are recovered by Donsker’s theorem. These are connected with Hermitian Brownian motion and the Gaussian Unitary Ensemble of random matrix theory. The connection we make between the path-transformationG(k)G^{(k)}and the Robinson-Schensted algorithm also provides a new formula and interpretation for the latter. This can be used to study properties of the Robinson-Schensted algorithm and, moreover, extends easily to a continuous setting.