bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for a single‐step mechanism in the origin of hyperdiploid childhood acute lymphoblastic leukemia
Authors: Paulsson Kajsa , Mörse Helena , Fioretos Thoas , Behrendtz Mikael , Strömbeck Bodil , Johansson Bertil 
Published: June 2005

AbstractHigh hyperdiploidy (>50 chromosomes) in childhood acute lymphoblastic leukemia (ALL) is characterized by nonrandom multiple trisomies and tetrasomies involving in particular chromosomes X, 4, 6, 8, 10, 14, 17, 18, and 21. This characteristic karyotypic pattern, the most common in pediatric ALL, may arise via a tetraploid state with subsequent loss of chromosomes, by sequential gains of chromosomes in consecutive cell divisions, or by simultaneous gain of chromosomes in a single mitosis. These alternatives may be distinguished by investigation of the allelic ratios of loci on the tetrasomic and disomic chromosomes. Previous studies of tetrasomy 21 and of the occurrence of uniparental disomies (UPDs) have suggested that the most likely mechanism is simultaneous gain. However, the other pathways have not been definitely excluded because complete analyses of all disomies and tetrasomies have never been performed. In the present study, we investigated 27 hyperdiploid ALLs by using 58 polymorphic microsatellite markers mapped to 23 of the 24 human chromosomes. Twenty‐six tetrasomies were analyzed (involving chromosomes X, 8, 10, 14, 18, and 21), and the frequency of UPDs was determined in 10 cases. In total, 200 chromosomes were studied. Equal allele dosage was observed in 24 of 26 tetrasomies, and only 7 UPDs were found. These data strongly suggest that hyperdiploidy in childhood ALL generally arises by a simultaneous gain of all additional chromosomes in a single abnormal mitosis. © 2005 Wiley‐Liss, Inc.
Semiparametric Bayesian inference in multiple equation models
Authors: Koop Gary , Poirier Dale J. , Tobias Justin 
Published: June 2005

AbstractThis paper outlines an approach to Bayesian semiparametric regression in multiple equation models which can be used to carry out inference in seemingly unrelated regressions or simultaneous equations models with nonparametric components. The approach treats the points on each nonparametric regression line as unknown parameters and uses a prior on the degree of smoothness of each line to ensure valid posterior inference despite the fact that the number of parameters is greater than the number of observations. We develop an empirical Bayesian approach that allows us to estimate the prior smoothing hyperparameters from the data. An advantage of our semiparametric model is that it is written as a seemingly unrelated regressions model with independent normal–Wishart prior. Since this model is a common one, textbook results for posterior inference, model comparison, prediction and posterior computation are immediately available. We use this model in an application involving a two‐equation structural model drawn from the labour and returns to schooling literatures. Copyright © 2005 John Wiley & Sons, Ltd.
Distribution approximations for cointegration tests with stationary exogenous regressors
Authors: Boswijk H. Peter , Doornik Jurgen A. 
Published: June 2005

AbstractThe distribution of a functional of two correlated vector‐Brownian motions is approximated by a Gamma distribution. This functional represents the limiting distribution for cointegration tests with stationary exogenous regressors, but also for cointegration tests based on a non‐Gaussian likelihood. The approximation is accurate, fast and easy to use in comparison with both tabulated critical values and simulated p‐values. The proposed procedure is applied to a UK model investigating purchasing power parity. Copyright © 2005 John Wiley & Sons, Ltd.
A bivariate count data model for household tourism demand
Authors: Hellström Jörgen 
Published: June 2005

AbstractHouseholds' choice of the number of leisure trips and the total number of overnight stays is empirically studied using Swedish tourism data. A bivariate hurdle approach separating the participation (to travel and stay the night or not) from the quantity (the number of trips and nights) decision is employed. The quantity decision is modelled with a bivariate mixed Poisson lognormal model allowing for both positive as well as negative correlation between count variables. The observed endogenous variables are drawn from a truncated density and estimation is pursued by simulated maximum likelihood. The estimation results indicate a negative correlation between the number of trips and nights. In most cases own price effects are as expected negative, while estimates of cross‐price effects vary between samples. Copyright © 2005 John Wiley & Sons, Ltd.
A note on group colorings
Authors: Král' Daniel , Pangrác Ondřej , Voss Heinz‐Jürgen 
Published: June 2005

AbstractWe study a concept of group coloring introduced by Jaeger et al. We show that the group chromatic number of a graph with minimum degree δ is greater than δ/(2, ln δ) and we answer several open questions on the group chromatic number of planar graphs: a construction of a bipartite planar graph with group chromatic number four and a 3‐colorable planar graph with group chromatic number five are presented. We also observe that several upper bounds on the choice number for various subclasses of planar graphs also translate to the concept of group colorings. © 2005 Wiley Periodicals, Inc. J Graph Theory
An improved synthesis of substituted [11C]toluenes via Suzuki coupling with [11C]methyl iodide
Authors: Hostetler Eric D. , Terry Garth E. , Donald Burns H. 
Published: June 2005

AbstractToluene derivatives are often found in drug‐like molecules, and are therefore desirable as radiolabelled moieties. The desire for an alternate to the Stille coupling led us to investigate the feasibility of the Suzuki coupling. We have found the Suzuki coupling route to be a robust alternative to the Stille coupling for the synthesis of functionalized [11C]toluene derivatives from [11C]methyl iodide. The avoidance of potentially toxic tin‐containing by‐products is an added advantage. The products synthesized via Suzuki coupling with [11C]methyl iodide were isolated in generally high yields (56–92%), with high radiochemical purity (>95%) and specific radioactivity (>4000 Ci/mmol) in less than 20 min following production of [11C]methyl iodide. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis of 2‐[(2‐chloro‐2′‐[18F]fluoroethyl)amino]‐2H‐1,3,2‐oxazaphosphorinane‐2‐oxide (18F‐fluorocyclophosphamide), a potential tracer for breast tumor prognostic imaging with PET
Authors: Lacan Goran , Kesner Amanda L. , Gangloff Anne , Zheng Lei , Czernin Johannes , Melega William P. , Silverman Daniel H. S. 
Published: June 2005

AbstractA fluorine‐18 labeled analog of the widely used chemotherapeutic agent cyclophosphamide was synthesized as a tracer for prognostic imaging with positron emission tomography. 2‐[(2‐Chloro‐2′‐[18F]fluoroethyl)amino]‐2H‐1,3,2‐oxazaphosphorinane‐2‐oxide (18F‐fluorocyclophosphamide), was prepared by direct halogen exchange reaction from the parent cyclophosphamide. In small‐scale syntheses, radiochemical yields of up to 4.9% and specific activities of 960 Ci/mmol were achieved in a total synthesis time of 60–75 min. The [18F]‐labeled cyclophosphamide analog with radioactive purity >99% and chemical purity >96% was suitable for in vivo (microPET imaging) and ex vivo studies of a murine model of human breast tumors. Copyright © 2005 John Wiley & Sons, Ltd.
Purinergic mediated changes in Ca2+ mobilization and functional responses in microglia: Effects of low levels of ATP
Authors: McLarnon James G. 
Published: June 2005

AbstractMicroglia, the immune effector cells of the brain, are stimulated by a diversity of agents to transiently increase levels of intracellular calcium ([Ca2+]i). Changes in [Ca2+]i induced by compounds such as adenosine triphosphate (ATP) serve important roles in cellular signal transduction linking stimuli with cellular functional responses. Purinergic responses in microglia, like that in other cells, are mediated by two families of receptors classified as P2Y and P2X. Activation of metabotropic receptors (P2YR) leads to increased [Ca2+]i due to depletion of intracellular stores, a process that can trigger activation of Ca2+ entry through plasmalemmal store‐operated channels (SOC). Activation of ionotropic receptors (P2XR) is associated with influx of Na+ and Ca2+ and efflux of K+ through nonselective cationic channels, leading to cellular depolarization. An intriguing property of purinergic stimulation of microglia is the dependence of cellular responses on agonist concentration. As one example, activation of the subtype P2X7R by higher levels of ATP (millimolar range), leads to a marked enhancement in microglial secretion of inflammatory mediators. Other members of the ionotropic P2XR family sensitive to lower levels of ATP, however, are also important in mediating microglial inflammatory responses in brain. At lower concentrations of ATP (100 μM), activation of SOC in human microglia is not only coupled to P2YR‐dependent depletion of internal stores, but is also modulated by ATP binding to a P2XR (not P2X7R). The modulation is consistent with a P2XR‐mediated influx of Na+ and inhibition of SOC by depolarization. In this review, a primary focus is placed on the effects of low concentrations of ATP (≤100 μM) to induce changes in [Ca2+]i and modify functional processes in microglia. In essence, responses mediated by purinergic receptors other than P2X7R are considered. © 2005 Wiley‐Liss, Inc.
Differential effects of acute and subchronic administration on phencyclidine‐induced neurodegeneration in the perinatal rat
Authors: Wang Cheng Z. , Johnson Kenneth M. 
Published: June 2005

AbstractAcute and subchronic administration of N‐methyl‐D‐aspartate antagonists to rats in the early postnatal period has been reported to produce widespread and selectively cortical neurotoxicity, respectively. To resolve this apparent discrepancy, we sought to clarify these data by determining the dose and temporal and regional characteristics of acute and subchronic phencyclidine (PCP)‐induced neurotoxicity. Measurement of degenerating neurons with the cupric silver technique following a single dose of PCP on postnatal day (PN) 7 revealed that neurodegeneration increased in all areas measured (frontal, parietal and cingulate cortices, striatum, hippocampus, subiculum, and thalamus) within 9 hr. Silver staining peaked at 9–16 hr and was then not detectable or was greatly reduced after 24 hr depending on the specific region. Dose‐response analysis at 9 hr showed that the lowest effective dose was 1, 3, and 10 mg/kg for the frontal cortex, hippocampus, and striatum, respectively. However, repeated PCP administration (10 mg/kg) on PN 7, 9, and 11 elicited an increase in silver staining only in the frontal cortex. To determine whether the loss of effect in the striatum and hippocampus was due to a “tolerance” mechanism or to a developmental phenomenon, we compared the effects of PCP given on PN 7, 9, or 11 with those of two doses given on PN 7 and 9 or three doses administered on PN 7, 9, and 11. Analysis of these experiments shows that both developmental factors and unknown mechanisms of tolerance underlie the apparent selective cortical neurotoxicity observed following subchronic PCP administration in perinatal rat pups. © 2005 Wiley‐Liss, Inc.
Study of volatile compounds of defective virgin olive oils and sensory evaluation: a chemometric approach
Authors: Procida Giuseppe , Giomo Andrea , Cichelli Angelo , Conte Lanfranco S 
Published: June 2005

AbstractIt is well known that olive oils are the only foods whose legal control must also involve sensory evaluation, and that a harmonised protocol is used for this purpose: EEC regulation 2568/91 and an IOOC trade norm of the 1990s introduced a standard method among those used to assess the quality of virgin oils, after which a modified method known as the ‘panel test’ was developed and adopted, firstly by the IOOC and later by the EEC. One problem in applying the panel method often depends on the lack of reference standards for training judges, in addition to, in some cases, a lack of exact knowledge of the origin of some defects; for these reasons, several judges have suggested the unification of some defects, even when these originate from different kinds of problems. In this paper we have applied headspace analyses to a number of samples of oils that were also characterised by a panel. Besides the samples, standard defective oils obtained by the IOOC and used for training sensory judges were also analysed, with the aim of obtaining a model for use in method validation. Seventy‐six peaks were detected and most of them identified by gas chromatography/mass spectrometry; their distribution was different in the samples characterised by different defects as assessed by the panel test. The well‐known compounds of virgin olive oils were detected, including the series of C6 compounds, whose importance in defining positive (‘green’ flavour) and negative (rancid) characteristics of olive oils is well known. No samples classified as extra virgin ever present peaks with magnitudes as great as those found in defective oils. Chemometric data evaluation was carried out and samples were clustered on the basis of the headspace composition; the results were found to agree with those of the panel test, so a number of compounds were related to the presence of particular defects. Copyright © 2005 Society of Chemical Industry
Application of pure and mixed probiotic lactic acid bacteria and yeast cultures for oat fermentation
Authors: Angelov Angel , Gotcheva Velitchka , Hristozova Tsonka , Gargova Stoyanka 
Published: June 2005

AbstractFermentation of a prebiotic containing oat substrate with probiotic lactic acid bacteria and yeast strains is an intriguing approach for the development of new synbiotic functional products. This approach was applied in the present work by using pure and mixed microbial cultures to ferment a heat‐treated oat mash. Results show that the strains studied were appropriate for oat fermentation and the process could be completed for 6–10 h depending on the strain. The viable cell counts achieved within this time were above the required levels of 106–107 cfu ml−1 for probiotic products. Both single lactic acid bacteria strains and mixed cultures of the same strains with yeast were found suitable for oat fermentation. However, the pure LAB cultures attributed better flavour and shelf life of the oat drinks. The content of the prebiotic oat component beta‐glucan remained within 0.30–0.36% during fermentation and storage of the drinks obtained with each of the strains used. Thus, these products would contribute diet with the valuable functional properties of beta‐glucan. Also, the viability of pure and mixed cultures in the oat products was good: levels of cell counts remained above the required numbers for probiotic products throughout the estimated shelf‐life period. Copyright © 2005 Society of Chemical Industry
Processing, Morphology, and Mechanical Properties of Liquid Pool Polypropylene with Different Molecular Weights
Authors: Stern Claudia , Frick Achim R. , Weickert Günter , Michler Goerg H. , Henning Sven 
Published: June 2005

AbstractSummary: The processability, morphology, and resulting mechanical properties of novel polypropylene (PP) samples of varying molecular weight ($\overline M _{\rm w}$) were studied. A series of homopolymer PP in a wide $\overline M _{\rm w}$ range from 101 000 to 1 600 000 g · mol−1 was polymerised in a liquid pool (LP) under defined conditions. The LP‐PP with a well‐known polymerisation history was manufactured into micro dumbbell specimens by means of a micro injection‐moulding process. The morphology and mechanical properties of the samples were studied by light microscopy, transmission and scanning electron microscopy, and a quasi‐static tensile test. Simulation of the filling behaviour of the molten polymer inside the mould shows that the shear rate increases as the molecular weight increases, up to a maximum shear rate of 750 000 s−1. In addition, the present crystallisation time of the high‐molecular‐weight PP samples is clearly lower than their retardation time; the long macromolecules do not have sufficient time to retard while cooling. As a result of the shear‐induced crystallisation, a highly oriented crystalline structure is formed as a function of the acting shear rate. SEM and TEM investigations show the existence of an oriented shish kebab structure. The density of the shish kebab increases as the molecular weight increases. Evaluations of the shear rate and the morphological structure indicate a critical shear rate of about 300 000 s−1. Above this shear rate level, shish kebab structures are favourably formed. The shear‐induced crystallisation and, therefore, the preferred formation of a highly oriented shish kebab structure lead, obviously, to unusual solid‐state properties of the analysed LP‐PP samples. With a tensile strength up to 100 N · mm−2 and an attainable strain at break of more than 30%, the mechanical performance is much higher than results ever reported in literature.True strain–stress behaviour of moulded the LP‐PP samples of different molecular weight.magnified imageTrue strain–stress behaviour of moulded the LP‐PP samples of different molecular weight.
A calculus for ideal triangulations of three‐manifolds with embedded arcs
Authors: Amendola Gennaro 
Published: June 2005

AbstractRefining the notion of an ideal triangulation of a compact three‐manifold, we provide in this paper a combinatorial presentation of the set of pairs (M,α), whereMis a three‐manifold andαis a collection of properly embedded arcs. We also show that certain well‐understood combinatorial moves are sufficient to relate to each other any two refined triangulations representing the same (M,α). Our proof does not assume the Matveev–Piergallini calculus for ideal triangulations, and actually easily implies this calculus. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diff(Rn) as a Milnor–Lie group
Authors: Glöckner Helge 
Published: June 2005

AbstractWe describe a construction of the Lie group structure on the diffeomorphism group Diff(Rn), modelled on the space D(Rn,Rn) of Rn‐valued test functions on Rn, in John Milnor's setting of infinite‐dimensional Lie groups. New tools are introduced to simplify this task. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Retracted: Blow‐up results for evolution problems on ℝn
Authors: Hakem Ali 
Published: June 2005

AbstractRetraction: The article “Blow‐up results for evolution problems on ℝn”, Math. Nachr. 278, 1033–1040 (2005); DOI 10.1002/mana.200310289 by Ali Hakem, published online on 8 June 2005 in Wiley Online Library (wileyonlinelibrary.com) has been retracted. The retraction is due to an identical publication in another journal, namely Bull. Belg. Math. Soc. – Simon Stevin, 12 (2005), no. 1, 73–82 and agreed by the author, the journal Editors‐in‐Chief and Wiley.
Second homology of Lie superalgebras
Authors: Iohara Kenji , Koga Yoshiyuki 
Published: June 2005

AbstractThe second homology of Lie superalgebras over a field of characteristic 0 extended over a supercommutative superalgebra A and their twisted version are obtained. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
$\bar \partial $‐energy integral and uniqueness of harmonic maps
Authors: Yao Guowu 
Published: June 2005

AbstractIn this paper, we introduce a new energy functional, $\bar \partial $‐energy functional, instead of the total energy functional to investigate the uniqueness of harmonic maps with respect to any given metric on the unit disk. Even in the setting that the Hopf differentials of harmonic maps are not integrable, certain uniqueness theorems of harmonic maps are obtained, which improve a result due to Marković and Mateljević in 1999. Moreover, a generalized energy‐minimizing property of harmonic maps is discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Convenient Method of Chain‐Growth Polycondensation for Well‐Defined Aromatic Polyamides
Authors: Yokozawa Tsutomu , Muroya Daichi , Sugi Ryuji , Yokoyama Akihiro 
Published: June 2005

AbstractSummary: For the convenient synthesis of well‐defined poly(N‐octyl‐p‐benzamide)s with low polydispersities, the polycondensation of methyl 4‐octylaminobenzoate (1) was investigated. Methyl ester monomer 1 polymerized with lithium 1,1,1,3,3,3‐hexamethyldisilazide (LHMDS) in the presence of an initiator in tetrahydrofuran at −10 °C. The highly pure polyamide with a defined molecular weight and a low polydispersity is obtained after simple treatment of the reaction mixture with aqueous NaOH solution, followed by evaporation.The chain‐growth polycondensation of 4‐octylaminobenzoic acid methyl ester (1) with lithium 1,1,1,3,3,3‐hexamethyldisilazide (LHMDS) to yield poly(N‐octyl‐p‐benzamide).magnified imageThe chain‐growth polycondensation of 4‐octylaminobenzoic acid methyl ester (1) with lithium 1,1,1,3,3,3‐hexamethyldisilazide (LHMDS) to yield poly(N‐octyl‐p‐benzamide).
Crosslinkable Composite Spheres and Capsules Synthesized by Heterocoagulation
Authors: Liu Xiyan , Niu Zhongwei , Xu Huifang , Guo Meili , Yang Zhenzhong 
Published: June 2005

AbstractSummary: Crosslinkable composite microspheres were prepared by heterocoagulation of epoxy resin nanoparticles onto polystyrene microspheres. The corresponding hollow microspheres were created after removal of the core. The surface morphology was tunable from smooth to rough by controlling the degree of crosslinking of the shell nanoparticles. A positively charged polyelectrolyte could be easily adsorbed onto the composite microspheres to facilitate further synthesis, e.g., layer‐by‐layer deposition and a sol‐gel process to form inorganic materials.An SEM image of the PS/EP/silica (where the EP was crosslinked slowly) microspheres after the cores have been removed.magnified imageAn SEM image of the PS/EP/silica (where the EP was crosslinked slowly) microspheres after the cores have been removed.
A Closed‐Loop Phase Diagram in a Weakly Interacting Polyolefin Copolymer Binary Blend System
Authors: Hu Haiqing , Chong Chuanbo , He Aihua , Zhang Chenggui , Fan Guoqiang , Dong Jin‐Yong , Han Charles C. 
Published: June 2005

AbstractSummary: The phase behavior of poly(ethylene‐co‐styrene) (PES) and poly(ethylene‐co‐butene) (PEB) blends has been studied. A closed‐loop phase diagram was clearly observed in this weakly interacting system as the styrene content in the PES decreased to about 1 mol‐%. At higher styrene contents, the phase loop starts to interplay with the crystallization transformation at lower temperatures.Phase diagram of PEB/PES blends. Phase boundary line is only for easy demonstration.magnified imagePhase diagram of PEB/PES blends. Phase boundary line is only for easy demonstration.
The maximum likelihood estimate in reduced‐rank regression
Authors: Eldén Lars , Savas Berkant 
Published: June 2005

AbstractIn previous work by Stoica and Viberg the reduced‐rank regression problem is solved in a maximum likelihood sense. The present paper proposes an alternative numerical procedure. The solution is written in terms of the principal angles between subspaces spanned by the data matrices. It is demonstrated that the solution is meaningful also in the case when the maximum likelihood criterion is not valid. A numerical example is given. Copyright © 2005 John Wiley & Sons, Ltd.