bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Crystals Based on Hypervalent Sulfur Fluorides: The trans‐(Trifluoromethyl)tetrafluorosulfuranyl Group
Authors: Kirsch Peer , Hahn Alexander 
Published: December 2005

AbstractSelective direct fluorination provides a convenient access to new classes of liquid crystals and dyes carrying a trans‐(trifluoromethyl)tetrafluorosulfuranyl group, a building block in organic chemistry with highly unusual and interesting properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Preparation and Chiroptical Studies of Dendritic Alkaloid Derivatives
Authors: Hahn Uwe , Kaufmann Astrid , Nieger Martin , Julínek Ondřej , Urbanova Marie , Vögtle Fritz 
Published: December 2005

AbstractA series of dendritic substituted alkaloids, deriving from quinine or atropine and Fréchet‐type dendrons up to generation three, have been prepared. Enantioseparation of the dendronized atropine ammonium salts was achieved by HPLC on chiral stationary phases. Investigation of the chiroptical properties of the series of dendrimers by circular dichroism spectroscopy revealed an influence of the chiral core on the dendritic part with regard to the intensities of the Cotton bands. The chirality was found to be dependent on its chiral elements and the generation of the formally achiral dendritic branch attached to the chiral core (“dendritic effect”). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Hierarchic multigrid iteration strategy for the discontinuous Galerkin solution of the steady Euler equations
Authors: Hillewaert Koen , Chevaugeon Nicolas , Geuzaine Philippe , Remacle Jean‐François 
Published: December 2005

AbstractWe study the efficient use of the discontinuous Galerkin finite element method for the computation of steady solutions of the Euler equations. In particular, we look into a few methods to enhance computational efficiency. In this context we discuss the applicability of two algorithmical simplifications that decrease the computation time associated to quadrature. A simplified version of the quadrature free implementation applicable to general equations of state, and a simplified curved boundary treatment are investigated. We as well investigate two efficient iteration techniques, namely the classical Newton–Krylov method used in computational fluid dynamics codes, and a variant of the multigrid method which uses interpolation orders rather than coarser tesselations to define the auxiliary coarser levels. Copyright © 2005 John Wiley & Sons, Ltd.
Detailed methylation analysis of CpG islands on human chromosome region 9p21
Authors: Weeks Robert J. , Morison Ian M. 
Published: December 2005

AbstractDeletion of 9p21 is the most commonly reported chromosomal abnormality in pediatric acute lymphoblastic leukemia, and published data suggest that the maternal chromosome is preferentially deleted. Preferential maternal deletion of 9p21 and reports of a differentially methylated region (DMR) and of parental effects in mice with lymphoma suggest there may be an unrecognized imprinted locus in this region. To screen for DMRs, we used the mcrBC/HpaII screening method and peripheral‐blood DNA. Of 36 CpG islands within an 8.5‐Mb region of 9p21, seven were identified as putative DMRs and were further analyzed by bisulfite sequencing. Neither any of the CpG islands nor a previously published putative DMR nearby showed evidence of differential parental methylation; however, the published DMR did demonstrate sequence‐dependent differential methylation. Our data, which showed heterogeneous and low‐level methylation of CpG islands, have obvious implications for methylation studies. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045‐2257/suppmat. © 2005 Wiley‐Liss, Inc.
Functional expression of Kir4.1 channels in spinal cord astrocytes
Authors: Olsen M.L. , Higashimori H. , Campbell S.L. , Hablitz J.J. , Sontheimer H. 
Published: December 2005

AbstractSpinal cord astrocytes (SCA) have a high permeability to K+ and hence have hyperpolarized resting membrane potentials. The underlying K+ channels are believed to participate in the uptake of neuronally released K+. These K+ channels have been studied extensively with regard to their biophysics and pharmacology, but their molecular identity in spinal cord is currently unknown. Using a combination of approaches, we demonstrate that channels composed of the Kir4.1 subunit are responsible for mediating the resting K+ conductance in SCA. Biophysical analysis demonstrates astrocytic Kir currents as weakly rectifying, potentiated by increasing [K+]o, and inhibited by micromolar concentrations of Ba2+. These currents were insensitive to tolbutemide, a selective blocker of Kir6.x channels, and to tertiapin, a blocker for Kir1.1 and Kir3.1/3.4 channels. PCR and Western blot analysis show prominent expression of Kir4.1 in SCA, and immunocytochemistry shows localization Kir4.1 channels to the plasma membrane. Kir4.1 protein levels show a developmental upregulation in vivo that parallels an increase in currents recorded over the same time period. Kir4.1 is highly expressed throughout most areas of the gray matter in spinal cord in vivo and recordings from spinal cord slices show prominent Kir currents. Electrophysiological recordings comparing SCA of wild‐type mice with those of homozygote Kir4.1 knockout mice confirm a complete and selective absence of Kir channels in the knockout mice, suggesting that Kir4.1 is the principle channel mediating the resting K+ conductance in SCA in vitro and in situ. © 2005 Wiley‐Liss, Inc.
Affective judgment and beneficial decision making: Ventromedial prefrontal activity correlates with performance in the Iowa Gambling Task
Authors: Northoff Georg , Grimm Simone , Boeker Heinz , Schmidt Conny , Bermpohl Felix , Heinzel Alexander , Hell Daniel , Boesiger Peter 
Published: December 2005

AbstractDamasio proposes in his somatic marker theory that not only cognitive but also affective components are critical for decision making. Since affective judgment requires an interplay between affective and cognitive components, it might be considered a key process in decision making that has been linked to neural activity in ventromedial prefrontal cortex (VMPFC). Using functional magnetic resonance imaging (fMRI), we examined the relationship between VMPFC, emotionally (unexpected)‐ and cognitively (expected)‐accentuated affective judgment, and beneficial decision making (Iowa Gambling Task; IGT) in healthy subjects. Neuronal activity in the VMPFC during unexpected affective judgment significantly correlated with both global and final performance in the IGT task. These findings suggest that the degree to which subjects recruit the VMPFC during affective judgment is related to beneficial performance in decision making in gambling. Hum Brain Mapp 2006. © 2005 Wiley‐Liss, Inc.
Subcellular localization, modification and protein complex formation of the cdk‐inhibitor p16 in Rb‐functional and Rb‐inactivated tumor cells
Authors: Nilsson Kristina , Landberg Göran 
Published: December 2005

AbstractThe cdk‐inhibitor p16 is a tumor suppressor gene that is inactivated in many forms of cancer. Despite numerous studies, the exact mechanism of regulation of p16 has not been clarified, although the status of retinoblastoma (Rb) seems to be one important factor that influences the p16 expression. The specificity and validity of cytoplasmic localization of p16 observed in some tumors has further been questioned. Here, by subcellular fractionation of Rb‐functional and Rb‐inactivated cell lines, we show that p16 indeed is expressed in the cytoplasm as well as in the nucleus. Post translational modifications of p16 in different subcellular compartments as well as its capacity to form protein complexes were further delineated. Two dimensional gel electrophoresis showed that two forms of p16 appeared in the cytoplasm, while only one form was detected in the nucleus. Samples of basal cell carcinoma and squamous cell carcinoma of the skin with either functional or non‐functional Rb also exhibited at least two forms of p16. In addition, cytoplasmic p16 bound cyclin dependent kinase (cdk)4/6, potentially indicating that p16 could have a function in the cytoplasm. © 2005 Wiley‐Liss, Inc.
Kinetics and mechanism of the reduction of monochloramine by hydroxylamine and hydroxylammonium ion
Authors: Robinson David M. , Hoppe Todd J. , Paslay Timothy J. , Purser Gordon H. 
Published: December 2005

AbstractThe kinetics and mechanism by which monochloramine is reduced by hydroxylamine in aqueous solution over the pH range of 5–8 are reported. The reaction proceeds via two different mechanisms depending upon whether the hydroxylamine is protonated or unprotonated. When the hydroxylamine is protonated, the reaction stoichiometry is 1:1. The reaction stoichiometry becomes 3:1 (hydroxylamine:monochloramine) when the hydroxylamine is unprotonated. The principle products under both conditions are Cl–, NH+4, and N2O. The rate law is given by −[d[NH2Cl]/dt] = k+[NH3OH+][NH2Cl] + k0[NH2OH][NH2Cl]. At an ionic strength of 1.2 M, at 25°C, and under pseudo‐first‐order conditions, k+= (1.03 ± 0.06) ×103 L · mol−1 · s−1 and k0=91 ± 15 L · mol−1 · s−1. Isotopic studies demonstrate that both nitrogen atoms in the N2O come from the NH2OH/NH3OH+. Activation parameters for the reaction determined at pH 5.1 and 8.0 at an ionic strength of 1.2 M were found to be ΔH‡ = 36 ± 3 kJ · mol–1 and Δ S‡ = −66 ± 9 J · K−1 · mol−1, and Δ H‡ = 12 ± 2 kJ · mol−1 and Δ S‡ = −168 ± 6 J · K−1 · mol−1, respectively, and confirm that the transition states are significantly different for the two reaction pathways. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 124–135, 2006
Kinetics of Fe(II) reduction of cis‐halogeno(dodecylamine) bis(ethylenediamine)‐ cobalt(III) complex ion in aqueous solutions
Authors: Santhakumar K. , Kumaraguru N. , Arunachalam S. , Arumugham M. N. 
Published: December 2005

AbstractKinetics of reduction of the surfactant complex ions, cis‐chloro/bromo (dodecylamine)bis(ethylenediamine)cobalt(III) by iron(II) in aqueous solution was studied at 303, 308, and 313 K by spectrophotometry method under pseudo‐first‐order conditions, using an excess of the reductant. The second‐order rate constant remains constant below critical micelle concentration (cmc), but increases with cobalt(III) concentration above cmc, and the presence of aggregation of the complex itself alters the reaction rate. The rate of reaction was not affected by the added [H+]. Variation of ionic strength (μ) influences the reaction rate. Activation and thermodynamic parameters have been computed. It is suggested that the reaction of Fe2+ (aq) with cobalt(III) complex proceeds by the inner‐sphere mechanism. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 98–105, 2006
The elimination kinetics and mechanisms of ethyl piperidine‐3‐carboxylate, ethyl 1‐methylpiperidine‐3‐carboxylate, and ethyl 3‐(piperidin‐1‐yl)propionate in the gas phase
Authors: Monsalve Angiebelk , Rosas Felix , Tosta María , Herize Armando , Domínguez Rosa M. , Brusco Doris , Chuchani Gabriel 
Published: December 2005

AbstractThe gas‐phase elimination kinetics of the above‐mentioned compounds were determined in a static reaction system over the temperature range of 369–450.3°C and pressure range of 29–103.5 Torr. The reactions are homogeneous, unimolecular, and obey a first‐order rate law. The rate coefficients are given by the following Arrhenius expressions: ethyl 3‐(piperidin‐1‐yl) propionate, log k1(s−1) = (12.79 ± 0.16) − (199.7 ± 2.0) kJ mol−1 (2.303 RT)−1; ethyl 1‐methylpiperidine‐3‐carboxylate, log k1(s−1) = (13.07 ± 0.12)–(212.8 ± 1.6) kJ mol−1 (2.303 RT)−1; ethyl piperidine‐3‐carboxylate, log k1(s−1) = (13.12 ± 0.13) − (210.4 ± 1.7) kJ mol−1 (2.303 RT)−1; and 3‐piperidine carboxylic acid, log k1(s−1) = (14.24 ± 0.17) − (234.4 ± 2.2) kJ mol−1 (2.303 RT)−1. The first step of decomposition of these esters is the formation of the corresponding carboxylic acids and ethylene through a concerted six‐membered cyclic transition state type of mechanism. The intermediate β‐amino acids decarboxylate as the α‐amino acids but in terms of a semipolar six‐membered cyclic transition state mechanism. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 106–114, 2006
Mn(III) oxidation of peptides: A mechanistic investigation of kinetic variations in hydrophobic‐induced oxidation of tetrapeptides of elastin sequences
Authors: Srinivasa G. R. , Abiraj K. , Baba A. Ramesha , Gowda D. Channe 
Published: December 2005

AbstractFour tetrapeptide analogues of elastin sequences, glycyl‐glycyl‐alanyl‐proline (GGAP), glycyl‐glycyl‐valyl‐proline (GGVP), glycyl‐glycyl‐isoleucyl‐proline (GGIP), and glycyl‐glycyl‐phenylalanyl‐proline (GGFP) were synthesized, based on their increasing order of hydrophobicity, by a classical solution phase method and were characterized. These tetrapeptides (TETPs) were oxidized using Mn(OAc)3 in 25% acetic acid at 298 K, and the kinetics of the reaction was monitored spectrophotometrically at λmax = 400 nm. A first‐order dependence of rate on each of [Mn(OAc)3], [OAc−], and substrate [TETP], an inverse order dependence on [H+], has been observed. The rate is independent of [Mn(II)]. However, an inverse order dependence on varying the dielectric constant using various percentages (v/v) of acetic acid has also been observed, and but addition of anions such as Cl− and ClO4− has insignificant effect on the rate. Activation parameters have been evaluated using the Arrhenius and Erying plots. The oxidation products were isolated and characterized. Based on the results obtained, a plausible mechanism involving [Mn(OAc)4]− has been proposed. An apparent correlation was noted between the rate of oxidation of these TETPs by Mn(III) in the presence of sulfate ions in sulfuric acid medium and Mn(OAc)3 in the acetic acid medium. The rate of oxidation with Mn(OAc)3 was observed to be slower than with the former. The rate of oxidation of GGFP was found to be higher than GGIP, GGVP, and GGAP. This may be due to the presence of an aromatic side chain and/or because of the increased hydrophobicity. The overall order of rate of oxidation of TETPs is GGFP > GGIP > GGVP > GGAP, which also represents an increasing order of their hydrophobicity. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 38: 115–123, 2006
Generalized Jacobian rings for open complete intersections
Authors: Asakura Masanori , Saito Shuji 
Published: December 2005

AbstractIn this paper, we develop the theory of Jacobian rings of open complete intersections, which are pairs (X, Z) whereXis a smooth complete intersection in the projective space andZis a simple normal crossing divisor inXwhose irreducible components are smooth hypersurface sections onX. Our Jacobian rings give an algebraic description of the cohomology of the open complementX – Zand it is a natural generalization of the Poincaré residue representation of the cohomology of a hypersurface originally invented by Griffiths. The main results generalize Macaulay's duality theorem and Donagi's symmetrizer lemma for usual Jacobian rings for hypersurfaces. A feature that distinguishes our generalized Jacobian rings from usual ones is that there are instances where duality fails to be perfect while the defect can be controlled explicitly by using the defining equations ofZinX. Two applications of the main results are given: One is the infinitesimal Torelli problem for open complete intersections. Another is an explicit bound for Nori's connectivity in case of complete intersections. The results have been applied also to study of algebraic cycles in several other works. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectral analysis of fourth order differential operators I
Authors: Behncke Horst 
Published: December 2005

AbstractWe study the spectral theory of differential operators of the form

on ℒ2w (0, ∞). By means of asymptotic integration, estimates for the eigenfunctions andM ‐matrix are derived. Since the M ‐function is the Stieltjes transform of the spectral measure, spectral properties of τ are directly related to the asymptotics of the eigenfunctions. The method of asymptotic integration, however, excludes coefficients which are too oscillatory or whose derivatives decay too slowly. Consequently there is no singular continuous spectrum in all our cases. This was found earlier for Sturm–Liouville operators, for which theWKB method provides a good approximation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear approximation in α ‐modulation spaces
Authors: Borup Lasse , Nielsen Morten 
Published: December 2005

AbstractThe á ‐modulation spaces are a family of spaces that contain the Besov and modulation spaces as special cases. In this paper we prove that brushlet bases can be constructed to form unconditional and even greedy bases for the α ‐modulation spaces. We study m ‐term nonlinear approximation with brushlet bases, and give complete characterizations of the associated approximation spaces in terms of α ‐modulation spaces. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gleason's problem for harmonic mixed norm and Bloch spaces in convex domains
Authors: Hu Zhangjian 
Published: December 2005

AbstractLet Ω ⊂ Rn be a bounded convex domain with C 2 boundary. Given 0 < p, q ≤ ∞ and a normal weight function φ (r ), let Hp,q,φ be the harmonic mixed norm space on Ω. In this paper we prove that Gleason's problem (Ω, a , Hp,q,φ ) is always solvable for any reference point a ∈ Ω. Also, Gleason's problem for the harmonic φ ‐Bloch (little φ ‐Bloch) space is solvable. The parallel results for the holomorphic functions on bounded convex domains in Cn are obtained. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Existence and asymptotic behavior of positive solutions of higher‐order quasilinear ordinary differential equations
Authors: Naito Manabu 
Published: December 2005

AbstractThe existence of non‐extreme positive solutions of n th‐order quasilinear ordinary differential equations is discussed. In particular, necessary and sufficient integral conditions for the existence of non‐extreme positive solutions are established for a certain class of equations. Basic results to a classical ordinary differential equation are generalized. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Contribution of mass spectrometry to assess quality of milk‐based products
Authors: Guy Philippe A. , Fenaille François 
Published: December 2005

AbstractThe vast knowledge of milk chemistry has been extensively used by the dairy manufacturing industry to develop and optimize the modern technology required to produce high‐quality milk products to which we are accustomed. A thorough understanding of the chemistry of milk and its numerous components is essential for designing processing equipment and conditions needed for the manufacture and distribution of high‐quality dairy products. Knowledge and application of milk chemistry is also indispensable for fractionating milk into its principal components for use as functional and nutritional ingredients by the food industry. For all these reasons, powerful analytical methods are required. Because of the complexity of the milk matrix, mass spectrometry, coupled or not to separation techniques, constitutes a key tool in this area. In the present manuscript, we review the contribution and potentialities of mass spectrometry‐based techniques to assess quality of milk‐based products. © 2005 Wiley Periodicals, Inc. Mass Spec Rev 25:290–326, 2006
Phenotypic changes associated with DYNACTIN‐2 (DCTN2) over expression characterise SJSA‐1 osteosarcoma cells
Authors: Bransfield Kieran L. , Askham Jon M. , Leek Jack P. , Robinson Philip A. , Mighell Alan J. 
Published: December 2005

AbstractDYNACTIN‐2 (DCTN2) localises to chromosome 12q13‐q15, a region prone to stable amplification in several cancers. Transient DCTN2 overexpression has a significant impact on cellular phenotype primarily due to disruption of the DYNEIN‐dynactin motor. Changes reported include alterations of microtubule‐directed movement of molecular (e.g. TP53) and organelle (e.g. Golgi) cargoes towards the nucleus, centrosome biology, cellular movement and mitosis with a potential predisposition to mitotic block and polyploidy. These changes would be expected to be of relevance to carcinogenesis. To investigate this, we report the first study of DCTN2 genomic amplification and sustained DCTN2 overexpression in cancer cells. QFMPCR was employed to characterise the extent of chromosome 12q13‐q15 amplicons in SJSA‐1, SJRH30, U373MG and CCF‐STTG1 cancer cells. DCTN2 amplification was present in SJSA‐1, U373MG and SJRH30 cells, yet was incomplete at the 5′‐end in SJRH30 cells. Only SJSA‐1 cells were characterised by DCTN2 overexpression on Western blot analyses. Microscopy studies distinguished SJSA‐1 cells by greater DCTN2 immunofluorescence and diminished centrosome and 58K protein Golgi‐marker focus compared to SJRH30 cells. Indirect evidence derived from the published work of others indicated that TP53 transport into the nucleus was unimpaired. Furthermore, we observed that SJSA‐1 cells were easy to propagate. In conclusion, persistent DCTN2 overexpression can be tolerated in SJSA‐1 cancer cells despite phenotypic abnormalities predicted from transient overexpression studies. This preliminary study does not support a major role for DCTN2 overexpression in carcinogenesis, although further studies would be necessary to confirm this. © 2005 Wiley‐Liss, Inc.
Apple flavonoids inhibit growth of HT29 human colon cancer cells and modulate expression of genes involved in the biotransformation of xenobiotics
Authors: Veeriah Selvaraju , Kautenburger Tanja , Habermann Nina , Sauer Julia , Dietrich Helmut , Will Frank , Pool‐Zobel Beatrice Louise 
Published: December 2005

AbstractFlavonoids from fruits and vegetables probably reduce risks of diseases associated with oxidative stress, including cancer. Apples contain significant amounts of flavonoids with antioxidative potential. The objectives of this study were to investigate such compounds for properties associated with reduction of cancer risks. We report herein that apple flavonoids from an apple extract (AE) inhibit colon cancer cell growth and significantly modulate expression of genes related to xenobiotic metabolism. HT29 cells were treated with AE at concentrations delivering 5–50 µM of one of the major ingredients, phloridzin (“phloridzin‐equivalents,” Ph.E), to the cell culture medium, with a synthetic flavonoid mixture mimicking the composition of the AE or with 5–100 µM individual flavonoids. HT29 cell growth was inhibited by the complex extract and by the mixture. HT29 cells were treated with nontoxic doses of the AE (30 µM, Ph.E) and after 24 h total RNA was isolated to elucidate patterns of gene expression using a human cDNA‐microarray (SuperArray®) spotted with 96 genes of drug metabolism. Treatment with AE resulted in an upregulation of several genes (GSTP1, GSSTT2, MGST2, CYCP4F3, CHST5, CHST6, and CHST7) and downregulation of EPHX1, in comparison to the medium controls. The enhanced transcriptional activity of GSTP1 and GSTT2 genes was confirmed with real‐time qRT‐PCR. On the basis of the pattern of differential gene expression found here, we conclude that apple flavonoids modulate toxicological defense against colon cancer risk factors. In addition to the inhibition of tumor cell proliferation, this could be a mechanism of cancer risk reduction. © 2005 Wiley‐Liss, Inc.