bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distributed Optimization with a Two-Dimensional Drying Model of a Board, Built up by Sapwood and Heartwood
Authors: Carlsson Peter 
Published: October 2004

Summary
Optimization with distributed computing is performed on a two-dimensional orthotropic drying model which allows boards with arbitrary outtake of the log and sapwood/heartwood distribution in the cross section. Drying schedules with an optimized variation of temperature and humidity which yields minimized drying time are created at the same time as moisture, stress and deformation levels are considered. A numerical example with distributed computing of a board with a mixture of sapwood and heartwood is presented. Drying starts from the fibre saturation point.
The Effect of Pressure Steaming on the Steady State Ion Diffusion and Drift Speed in Wood
Authors: Törnqvist Magnus , Hurme Tapio , Rosenholm Jarl B. 
Published: October 2004

Summary
Diffusion tests were made in wood chips of northern pine (Pinus sylvestris), birch (Betula verrucosa) and spruce (Picea abies). The chips were pre-treated in two different ways, immersion into water and by steaming. The new results covering very high concentrations, 0.5 mol/dm3 up to 1.5 mol/dm3, of NaCl, NaOH and Na2S were recorded for both ways of pre-treating samples. The results were graphically compared, with the main emphasis on the differences between the immersed and the steamed samples. The differences were shown to be not only in the magnitude of the flow; clear differences in the concentration dependencies were also noticed. Spruce was more affected by the pre-steaming than pine and birch.
Facilitating Group Learning on the Internet
Authors: Holt Margaret E. , Kleiber Pamela B. , Swenson Jill Dianne , Rees E. Francis , Milton Judy 
Published: October 2004

AbstractSummarizing research conducted from 1994 to 1996 with on‐line National
Issues Forums, this chapter describes group learning on the Internet and
how it can be facilitated.
Developmental toxicity evaluation of ibuprofen and tolmetin administered in triple daily doses to Wistar CRL:(WI)WUBR rats
Authors: Burdan Franciszek 
Published: October 2004

AbstractBACKGROUND: Ibuprofen and tolmetin are popular non‐steroidal anti‐inflammatory drugs. Previous animal studies taken with single daily doses showed their good prenatal tolerability. However, since both cyclooxygenase (COX) inhibitors have a short half‐life, the current report presents drug developmental effects after triple daily doses administration, as they are used in human. METHODS: Drugs were separately, orally dosed to pregnant rats triple daily 8 hr apart from day 8 to 21 (GD=1‐plug day). The total daily doses were set at 25.5, 255.0, and 600.0 mg/kg for ibuprofen and 25.5, 255.0, and 2550.0 mg/kg for tolmetin. Fetuses were delivered on GD 21 and routinely examined. Comprehensive clinical and developmental measurements were done. RESULTS: Maternal toxicity and intrauterine growth retardation were found in groups exposed to the highest doses of both drugs. An increase of external variations was reported in groups exposed to the middle and highest dose of ibuprofen and to the highest dose of tolmetin. Skeletal variations were significantly different only in litters treated with the highest doses of the drugs. Pooled statistical analysis showed a higher incidence of midline and ventricular septal (VSD) defect in rat fetuses exposed to COX inhibitors when compared with historical control data. For ibuprofen, the influence on VSD was similar to aspirin. CONCLUSION: Both COX inhibitors were toxic to dams in the highest doses evaluated, which caused a significantly greater incidence of intrauterine growth retardation and developmental variations. Birth Defects Res B 71:321–330, 2004. © 2004 Wiley‐Liss, Inc.
Detection of tissue‐specific effects by methotrexate on differentiating mouse embryonic stem cells
Authors: Pellizzer Cristian , Bello Ezia , Adler Sarah , Hartung Thomas , Bremer Susanne 
Published: October 2004

AbstractBACKGROUND: Pluripotent embryonic stem (ES) cells offer a unique possibility to monitor the differentiation of several cell types in vitro. This study attempts to identify marker genes during in vitro cell differentiation of murine ES cells and allow a prediction of chemical effects on cell differentiation of specific target tissues. The study focused on the expression pattern of key genes involved in cardiomyocyte and osteoblast differentiation: Oct‐4, Brachyury, Nkx2.5, α myosin heavy chain, Cbfa1, and Osteocalcin. METHODS: Methotrexate was selected due to its well‐characterized teratogenic effects. Several in vivo studies have demonstrated the specific interactions of methotrexate with bone formation whereas the cardiovascular system is not specifically affected after exposure to low concentration. The capability of murine ES cells to differentiate in vitro into cardiomyocytes as well as into osteoblasts have been used to demonstrate the target cell specificity in vitro, at non‐cytotoxic concentration. RESULTS: Exposure of differentiating ES cells did not result in any gene profile modification of the selected cardiomyocyte specific genes, whereas the expression of osteoblast specific key genes, Cbfa1 and Osteocalcin, decreased. At the latter stages of skeletal differentiation we observed a 30% decrease in gene expression for Cbfa1 and a 60% decrease for Osteocalcin, with reference to the control. Early marker genes for undifferentiated cells and mesodermal cells were not modified after methotrexate treatment. CONCLUSIONS: These results show the possibility to integrate specific in vitro tests for teratogenicity in a test strategy for developmental toxicity. Birth Defects Res B 71:331–341, 2004. © 2004 Wiley‐Liss, Inc.
Die Rolle des Animismus bei der Vermittlung chemischer Sachverhalte
Authors: Püttschneider Martin , Lück Gisela 
Published: October 2004

AbstractWie lassen sich Naturphänomene und deren naturwissenschaftliche Deutung motivierend und nachhaltig vermitteln? Eine wirklich befriedigende Antwort scheint wohl nicht gefunden zu sein, denn Chemie gilt in der öffentlichen Diskussion immer noch als unverständlich. Nicht ohne Grund wurde Ende der 80er Jahre das PUSH‐Programm entwickelt (Public Understanding of Science and Humanities). In diesem Programm sollen einer breiten Öffentlichkeit wissenschaftliche Begriffe, Problemstellungen und Konzepte verständlich dargeboten werden, so dass es zu einer Wertschätzung der naturwissenschaftlichen und technischen Beiträge in der Gesellschaft kommt [1].Verständliche Vermittlung muss frühzeitig in der Schule beginnen, da dort die Grundlagen für ein nachhaltiges Interesse an naturwissenschaftlichen Fragestellungen gelegt werden. Ein nachlassendes Interesse gegenüber naturwissenschaftlichen Fächern, insbesondere Chemie und Physik, zeigt sich bereits im Verlauf der Sekundarstufe I. Höner und Greiwe bestätigen Untersuchungen der Vorjahre und stellen fest: „In der 7. Klasse ist Chemie noch das drittbeliebteste Fach … Im Verlauf der Jahrgangsstufen verschlechtert sich der Wert in der neunten sowie noch einmal in der zehnten Klasse … zu den unbeliebtesten Fächern.”︁ [2] Es ist anzunehmen, dass die nachlassende Fachbeliebtheit auch langfristig und nachhaltig zu einem rückläufigen Interesse an chemischen Sachverhalten führt.Neben verschiedenen ursächlichen Faktoren ist hier insbesondere die Art der Vermittlung zu nennen. Der bewusste Einsatz von Animismen könnte durch seinen motivierenden Charakter einem nachlassenden Interesse entgegenwirken.
In vitro and in vivo characterization of TC‐1827, a novel brain α4β2 nicotinic receptor agonist with pro‐cognitive activity
Authors: Bohme Georg Andrees , Letchworth Sharon R. , Piot‐Grosjean Odile , Gatto Gregory J. , Obinu Marie‐Carmen , Caldwell William S. , Laville Michel , Brunel Pascale , Pellerin Rachel , Leconte Jean‐Pierre , Genevois‐Borella Arielle , Dubedat Pierre , Mazadier Martine , Pradier Laurent , Bencherif Merouane , Benavides Jesus 
Published: October 2004

AbstractNicotine activates specific receptors that are cation‐permeable ionic channels located in the central and autonomous nervous systems, as well as at the neuromuscular junction. Administration of nicotine to animals and humans has been shown to enhance cognitive processes. However, side effects linked to the activation of peripheral nicotinic receptors limit the usefulness of nicotine for the treatment of cognitive disorders such as Alzheimer's disease (AD) or mild cognitive impairments (MCI). The synthesis and properties of TC‐1827, a novel metanicotine derivative that activates brain α4β2 nicotinic receptors is described. TC‐1827 has high affinity for nicotine‐labeled receptors in the cortex (Ki=34 nM), full‐agonist intrinsic activity in α4β2‐mediated neurotransmitter release studies in synaptosomes, and has no functional activity at nicotinic receptors in ganglionic or muscular cell lines. The compound enhances long‐term potentiation in hippocampal slices, a form of synaptic plasticity thought to be involved in information storage at the cellular level. In vivo studies demonstrate that TC‐1827 dose‐dependently occupies thalamic nicotinic receptors labeled with [3H]‐cytisine, increases cortical extracellular acetylcholine levels following oral administration, and enhances cognitive performance in rat and mice behavioral procedures of learning and memory. Pharmacokinetic studies in mice, rats, and monkeys indicated that TC‐1827 has good oral absorption with a first pass effect resulting in bioavailabilities of 13–65% across dose/species. Cardiovascular safety studies indicate good cardiovascular tolerability for this compound. The present data demonstrate that TC‐1827 is a selective and potent activator of brain α4β2 nicotinic receptors and is a prototypical member of a new class of compounds with potential utility in the symptomatic treatment of cognitive disorders including AD and MCI. Drug Dev. Res. 62:26–40, 2004. © 2004 Wiley‐Liss, Inc.
KP544, a nerve growth factor amplifier: Pharmacokinetics, safety, and efficacy in the rat
Authors: Krenitsky Thomas A. , Dillberger John , Zotova Elena , Arezzo Joseph C. , Koprich James B. , Mortazavi Farzad , Gates Timothy A. , Dunbar Gary L. 
Published: October 2004

AbstractIn cultured cells, KP544 [2‐amino‐5‐(4‐chlorophenylethynyl)‐4‐(4‐trans‐hydroxycyclohexyl amino) pyrimidine] amplifies differentiation initiated by nerve growth factor (NGF) or cAMP. This report describes the pharmacokinetics, safety, and neuroprotective efficacy of KP544 in rats. After an oral dose of 10 mg/kg KP544 was 25% bioavailable with a plasma half‐life of 1.3 h and brain levels 6‐fold higher than plasma levels at 4 and 8 h post‐dose. In a safety study, daily oral dosing for 30 days at 10 and 100 mg/kg was well tolerated. The favorable pharmacokinetic and safety profiles, together with its amplification of NGF in vitro, prompted evaluation of KP544 in two models involving NGF deficiencies. In the first model, brains were lesioned with intrastriatal injections of quinolinic acid. KP544 at oral doses of 0.02 to 1.0 mg/kg/day almost completely prevented the resulting learning deficits as evaluated using a radial‐arm‐water maze. At the lowest dose, there was a slower onset of functional improvement. These effects were accompanied by reductions (16–34%) in the striatal lesion size that were greatest at the highest dose and comparable to those seen with NGF therapy. The second model involved a peripheral neuropathy induced by taxol that is associated with decreases in NGF. KP544 at oral doses of 0.1–10 mg/kg/day decreased the severity of the neuropathy as measured by caudal nerve conduction velocities (30–70% return to control values). In both models, KP544 had a large therapeutic index suggesting its potential as a new approach for treating clinical disorders involving deficiencies in NGF. Drug Dev. Res. 62:60–70, 2004. © 2004 Wiley‐Liss, Inc.
Thallium−Arene Contacts in a Rare Yttrium Tris(pyrazolyl)hydroborate “ate” Complex
Authors: Kunrath Fábio A. , Casagrande Osvaldo L. , Toupet Loic , Carpentier Jean‐François 
Published: October 2004

AbstractA salt elimination reaction between [YCl3(THF)3.5] and 1 or 2 equiv. of Tl(TpMs*) [TpMs* = HB(3‐mesitylpyrazolyl)2(5‐mesitylpyrazolyl)−] leads in both cases to single metathesis, giving a mixture of the mono‐TpMs* complex [YCl3(TpMs*)Tl] (1) and another complex, [YCl2(TpMs**)] (2) [TpMs** = HB(3‐mesitylpyrazolyl)(5‐mesitylpyrazolyl)2−], that results from the transfer of a second mesityl group to the 5‐position of the pyrazolyl ring. The solid‐state structure of 1 shows a unique “ate” dimeric structure with the Tl+ cations coordinated by two μ2‐ and two μ3‐bridging Cl atoms as well as two η3‐mesityl ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Diastereomeric Halfsandwich Rhenium Complexes Containing Hemilabile Phosphane Ligands
Authors: Dilsky Stefan , Schenk Wolfdieter A. 
Published: October 2004

AbstractThe syntheses and some typical reactions of diastereomeric rhenium complexes [CpRe(NO)(CO){P(Ph)(R)(R′)}]BF4 (R = Me, Ph; R′ = 2‐C6H4OMe, CH2C4H3S, CH2C4H7O) (3a−e) are described. Reduction of the carbonyl ligand with NaBH4 in THF gave the corresponding methyl complexes [CpRe(NO){P(Ph)(R)(R′)}(CH3)] (4a−e). Acid treatment of the methyl complexes leads to liberation of methane and coordination of the additional donor site of the potentially bidentate phosphane ligand. Of the chelate complexes 5a−e, those with R′ = 2‐C6H4OMe (5a, d) decomposed in solution at room temperature. In donor solvents, the chelate ring opens giving the stable solvated complexes [CpRe(NO){P(Ph)(R)(R′)}](solvent)]BF4 (solvent = CH3CN, THF) (6b−e, 7d). The new compounds are thus suitable starting materials for the syntheses of diastereomeric rhenium complexes [CpRe(NO){P(Ph)(R)(R′)}(L)]BF4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Macromol. Theory Simul. 8/2004
Authors: Pirozzi Beniamino , Napolitano Roberto , Esposito Simona 
Published: October 2004

Cover: The figure shows the map of the conformational energy of syndiotactic 1,2‐poly(1,3‐butadiene) in the crystalline field as a function of the two independent torsion angles in the main chain. The loci of the points corresponding to the helical s(2/1)2 symmetry of the chain and the point corresponding to the tcm symmetry are also shown. Energy maps have been calculated also for various vinyl polymers deriving from 1,3‐diene monomers in order to predict the values of the conformational parameters for each polymer.Further details can be found in the Full Paper by B. Pirozzi,* R. Napolitano, and S. Esposito on page 679.
Structural and spectral assignment by two‐dimensional NMR of two new derivatives of the abietane diterpenoid taxodione
Authors: Rodríguez Benjamín 
Published: October 2004

AbstractTwo new abietane derivatives were obtained by treatment of the diterpene taxodione with diazomethane. Their structures were determined by mass spectrometry and NMR studies, including one‐ and two‐dimensional experiments. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of the association and flexibility of cationic lipidic peptide dendrons by NMR spectroscopy
Authors: Zloh Mire , Ramaswamy Chandrasekaran , Sakthivel Thiagarajan , Wilderspin Andy , Florence Alexander T. 
Published: October 2004

AbstractThe cationic peptide dendrons synthesized and studied are lower generation polylysine‐based partial dendrimers with or without lipid chains in the core. The dendrons with lipidic chains can be utilized as protein and liposomal mimics because of their unique structural properties. The full assignments of three different dendrons (L)7(NH2)8, (C14)1(L)7(NH2)8 and (C14)3(L)7(NH2)8 were obtained in D2O and H2O/D2O using a 500 MHz NMR spectrometer. The hydrophobic lipidic core of branched polylysine dendrons was found to induce aggregation upon increasing concentration. Because non‐lipidic dendrons do not self‐assemble, the behaviour and internal structural features of two different dendrons with one and three C14 hydrocarbon chains were explored. The critical association concentration clearly depends on the number of core hydrophobic residues and the association starts at 0.025 mM for (C14)1(L)7(NH2)8 and 0.05 mM for (C14)3(L)7(NH2)8. Chemical shift analysis also revealed that the hydrophobic chains of the dendrons associate in the core, whereas the polar head groups (NH2) are mainly located at the surfaces of the aggregates. The T1 relaxation time measurements showed that the mobility of the hydrocarbon chain is greater with the monomeric form of dendron (C14)1(L)7(NH2)8 than that of monomer (C14)3(L)7(NH2)8. The inter‐chain hydrophobic interactions restrict the flexibility of the dendron with three hydrocarbon chains. As expected, the flexibility of the monomeric form is higher than that of the aggregated state for both of the dendrons. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of the volume and temperature on the global and segmental dynamics in poly(propylene glycol) and 1,4‐polyisoprene
Authors: Roland C. M. , Paluch M. , Casalini R. 
Published: October 2004

AbstractPublished dielectric relaxation measurements for poly(propylene glycol) and 1,4‐polyisoprene are analyzed to determine the relative effects that thermal energy and volume have on the temperature dependence of the normal‐mode relaxation times, and these are compared with their effects on the temperature dependence of the local segmental relaxation times. For both polymers at temperatures well above the glass‐transition temperature, both relaxation modes are governed more by the thermal energy than by the volume, although the latter's contribution is not negligible. Such a result is consistent with an assumption underlying models for polymer viscoelasticity, such as the Rouse and tube models, that the friction coefficient governing motions over large length scales can be identified with the local segmental friction coefficient. Moreover, the relaxation data for both the segmental and normal modes superimpose when expressed as a function of the product of the temperature and volume, the latter being raised to a power. This scaling form arises from an inverse power law for the repulsive part of the intermolecular potential. The value of the exponent on the volume is the same for the normal and segmental motions and for both polymers indicates a relatively soft potential. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4313–4319, 2004
Raman scattering studies in two kinds of Ge nanosystems under hydrostatic pressure
Authors: Teo K. L. , Shen Z. X. , Liu L. , Kolobov A. V. , Maeda Y. 
Published: October 2004

AbstractWe report Raman scattering of Ge nanocrystals (NCs) embedded in SiO2 matrix on Si substrate (Ge/SiO2/Si) and on quartz substrate (Ge/SiO2/quartz) under hydrostatic pressure. The pressure coefficient obtained for the Ge mode in the Ge/SiO2/quartz nanosystem is found to be almost twice as large com‐ pared with its corresponding bulk value. We explained our results using a simple elastic model, which describes the effective pressure transmitted from the matrix to the NCs. In Ge/SiO2/Si nanosystem, delamination of the SiO2 film from the Si substrate occurs at ∼23 kbar due to the large difference between the compressibility of the SiO2 matrix and Si substrate. The observed effect can be understood by the nonhomogeneous distribution of the elastic field in the Ge/SiO2/Si nanosystem using a finite element analysis. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure‐induced phase transition in ErH3
Authors: Moysés Araújo C. , Ferreira da Silva Antonio , Ahuja R. 
Published: October 2004

AbstractThe pressure‐induced structural phase transition in ErH3 is investigated using ab initio calculations. The electronic structure is calculated using the projected augmented wave (PAW) method and the transition pressure is obtained by fitting the energy–volume set to the Murnaghan equation of states. A structural phase transformation has been found accompanied by an insulator–metal transition at 17.0 GPa in good agreement with experimental findings. A similar phase transition is also predicted for GdH3. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of hydrostatic pressure on optical properties of InN and In‐rich group III‐nitride alloys
Authors: Li S. X. , Wu J. , Walukiewicz W. , Shan W. , Haller E. E. , Lu Hai , Schaff William J. , Saito Yoshiki , Nanishi Yasushi 
Published: October 2004

AbstractWe have used the diamond anvil cell technique to measure the hydrostatic pressure dependence of the optical absorption edge and photoluminescence peak energy of MBE grown InN, In‐rich In1–xGaxN (0 < x < 0.5) and In1–xAlxN (x = 0.25) alloys. Together with previous reports, our results show that the pressure coefficient of the absorption edge varies monotonically from about 3.0 ± 0.1 meV/kbar for InN to 4.2 meV/kbar in GaN and to 4.9 meV/kbar in AlN. The photoluminescence measurements yield significantly smaller pressure coefficients than the coefficients of the bandgap, which is attributed to emission associated with recombination via highly localized defect states. Samples which give small photoluminescence pressure coefficient usually have large Stokes shift. Based on the results of the absorption and photoluminescence measurements we are able to determine the absolute deformation potentials of the conduction and valence band edges of these alloys. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence of CaS:Eu2+ under hydrostatic pressure
Authors: Chen C. , Teo K. L. , Chong T. C. , Newman D. M. 
Published: October 2004

AbstractWe have studied the hydrostatic pressure dependence of the emission of CaS doped with Eu2+. For P ≥ 70 kbar, we observed the main the emission peak broadens and appears to ‘split’ into two peaks with the low‐energy peak increasing in intensity relative to the main energy peak. We proposed that more than one excited state could be thermally populated at room temperature. The quenching of the luminescence can be explained by the presence of an intervening state using a single configuration coordinate model. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman scattering studies of Ge/Si islands under hydrostatic pressure
Authors: Teo K. L. , Shen Z. X. , Schmidt O. G. 
Published: October 2004

AbstractRaman scattering under hydrostatic pressure is used to investigate the phonon modes of self‐assembled Ge islands grown by solid source molecular beam epitaxy. Our results show that the overlapping spectra of the Ge–Ge phonon and Si 2TA modes occur around 304 cm–1 at ambient pressure can be resolved at relatively low pressure of about 3 kbar. The mode Grüneisen parameter of the Ge–Ge phonon mode in quantum dot is found to be γ = 0.84 ± 0.01. The normalized Raman intensity profiles of Ge–Ge mode, exhibits a resonance enhancement peak at 2.37 eV. The pressure coefficient of this resonating electronic transition is ∼2.7 ± 0.5 meV/kbar, which is significantly smaller than the pressure shift of the E1 transition in bulk Ge. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature and pressure dependence of recombination processes in 1.5 μm InGaAlAs/InP‐based quantum well lasers
Authors: Sweeney S. J. , McConville D. , Massé N. F. , Bouyssou R.‐X. , Adams A. R. , Ahmad C. N. , Hanke C. 
Published: October 2004

AbstractThe improved thermal stability of InGaAlAs‐based lasers compared with InGaAs‐based lasers for 1.5 μm operation is investigated using a combination of low temperature and high pressure techniques. The results indicate that the improved performance of InGaAlAs‐based devices is due to a reduction in the contribution of the non‐radiative Auger recombination current, IAug, to the total threshold current, Ith, in the InGaAlAs devices. This is due to the higher conduction band offset made possible with the InGaAlAs system which results in a lower hole density in the quantum wells at threshold. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)