bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical modeling of microstriplines with substrates with arbitrarily varying thickness with the use of the TLM method
Authors: Ahyoud S. , El Moussaoui A. , Essaaidi M. , Khalladi M.
Published: August 2002

The symmetrical condensed‐node TLM method is used for the analysis of microstrip lines with substrates of arbitrary varying thickness. This numerical technique has been efficiently used for the computation of the propagation constant and the characteristic impedance of this structure. Moreover, it has been demonstrated that the shape of the microstrip substrate is also an important parameter for controlling the values of its characteristic impedance. The validity of the obtained results is proved by comparisons with those obtained from the literature. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 48–51, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10369
Analysis of the blocking performance of hybrid OCDM‐WDM transport networks
Authors: Mutafungwa Edward , Halme Seppo J.
Published: August 2002

This study focuses on the blocking performance of hybrid optical code‐division multiplexing wavelength‐division multiplexing (OCDM‐WDM) networks under dynamic traffic conditions. Novel lightpath concepts for those hybrid networks are introduced. Simulation of the blocking performance for different lightpath concepts indicate that networks upgraded with wavelength converters offer the best performance. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 61–68, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10374
Global analysis and realization of a wideband array (250 500 MHz) for RCS measurements in an anechoic chamber
Authors: Poey P. , Azevedo D. , Begaud X. , Daniel J. P. , Le Ray G.
Published: August 2002

A dual‐polarized array operating in the 250–500‐MHz frequency range is analyzed and realized for RCS measurements in an anechoic chamber. The elementary dual‐polarized source is presented, and then the array is completely analyzed with a parallel code solver. A comparison between computed and experimental results is given for the source impedance and radiation patterns of the array. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 68–70, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10375
Nondestructive determination of the longitudinal chromatic dispersion distribution along an optical fiber
Authors: Wai P. K. A. , Moldoveanu F. , Chen H. H. , Tsang Y. K.
Published: August 2002

A novel nondestructive technique is proposed to determine the longitudinal dispersion profile of an optical fiber which make uses of the output waveforms of the optical fiber from a set of input pulses and an optimization algorithm. The feasibility of the proposed method is demonstrated numerically. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 312–314, 2001.
On the capacitance and conductance calculations of integrated‐circuit interconnects with thick conductors
Authors: Ymeri Hasan , Nauwelaers Bart , Maex Karen
Published: August 2002

In this paper, a method for computing the capacitance and conductance matrices of multiconductor IC interconnects in a multilayered dielectric region is presented. The number of conductors and the number of dielectric layers are arbitrary. The conductors are very thick (as usual for on‐chip interconnects), and can be placed anywhere in the structure. The formulation is obtained by using a semianalytic Green's function of multilayer structures, which is integrated to a series expansion, valid for charge‐density distribution on the conductors. In addition, the quasianalytical evaluation of the entries of the Galerkin matrix leads to a very efficient and accurate computer code. The accuracy of the suggested method is validated by comparing it with the rigorous simulation data obtained from full‐wave solvers and the CAD‐oriented equivalent‐circuit approach. In our research, we have validated the capacitance and conductance matrices of interconnects on lossy silicon substrate over a wide range of frequencies up to 20 GHz. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 335–339, 2001.
A novel F‐probe‐fed broadband patch antenna
Authors: Ooi B. L. , Lee C. L. , Kooi P. S.
Published: August 2002

The characteristics of a novel rectangular patch with an offset F‐shaped probe are investigated. The patch height is approximately 9% of the designed wavelength. An impedance bandwidth of 36% and an average measured gain of approximately 5 dBi can be achieved for the first dominant mode. There is an additional higher order mode band, which extends the overall impedance bandwidth to 64% and provides an average measured gain of approximately 3 dBi. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 355–356, 2001.
Propagation‐parameter mapping method for efficient simulation of in‐line amplified transmission
Authors: Kim Yongwon , Lee Myungmoon , Lee Jintae , Yu Jinwoo
Published: August 2002

In this paper, a propagation parameter‐mapping method for an efficient simulation to evaluate the performance of in‐line optical amplified transmission line is proposed. The method helps to extract the propagation parameters for simplified simulation from both a single‐channel and a WDM transmission line. It has been shown in the simulation results that the simplified simulation can describe the propagation behavior of optical pulses very accurately, with less than only 3% difference in the eye‐opening ratio when compared with the normal simulation method, but with a great reduction of calculation time. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 364–368, 2001.
A possible role for spontaneous interleukin‐8 production by acute myeloid leukemic cells in angiogenesis related processes: Work in progress
Authors: de Bont Eveline S.J.M. , Vellenga Edo , Molema Grietje , van Wering Elisabeth , de Leij Lou F.M.H. , Kamps Willem A.
Published: August 2002

Background

Recently, the role of inter‐leukin‐8 (IL‐8) in angiogenesis was reported. We consequently addressed here the question whether IL‐8 produced by acute myeloid leukemia (AML) blasts might have a comparable function.

Procedure

In 21 pediatric patients with AML the role of AML derived IL‐8 in angiogenesis related processes were investigated. Therefore, IL‐8 protein and mRNA expression were measured and endothelial cell (EC) migration and proliferation assays were performed. In addition, bFGF and VEGF mRNA expression were measured by RT‐PCR.

Results

In the supernatant of the AML blasts, IL‐8 protein was present in a varying amount (median 0.86 μgL, range: 0.1–320 μg/L) and confirmed by RT–PCR. Normal bone marrow mononuclear cells secreted a significant lower amount of IL‐8 protein (median: 0.053 μg/L, range: 0.023–0.055 μg/L, P = 0.007).Seven of the 17 tested AML supernatants induced a varying low amount of EC proliferation compared to control media, which was not inhibited by anti‐IL‐8 antibodies. In contrast, in the EC migration assay, 15 out of the 17 AML supernatants tested, showed an increased EC migration (median fold increase: 1.97, range: 0.66–6.36, P = 0.002) compared to control medium. The increase in EC migration could partially be blocked by anti‐IL‐8 in 59% of the cases (18% decrease, range 0–62%, P = 0.003). Other contributors for the increase in EC migration were also determined. Vascular endothelial growth factor (VEGF) transcripts by RT‐PCR were demonstrated in six out of the nine tested AML cases, while no transcripts for basic fibroblast growth factor (VEGF) could be shown.

Conclusions

Neutralizing anti IL‐8 antibodies inhibit EC migration when stimulated with AML supernatant. This suggests a facilitating role for AML‐derived IL‐8 in an important step in angiogenesis. Med Pediatr Oncol 2001;37:511–517. © 2001 Wiley‐Liss, Inc.
Configuration and conformation of a novel uridine analogue: 1H and 13C NMR spectra of (5'S)‐1‐[2'‐(2‐hydroxyethyl)tetrahydropyran‐5'‐yl]‐1H‐pyrimidine‐2,4‐dione
Authors: Balayiannis George , Papaioannou Dionissios , Troganis Anastassios
Published: August 2002

A combination of homo‐ and heteronuclear 1D and 2D NMR techniques provided the assignment of the 1H and 13C resonances of the major component of a reaction product consisting of the two possible diastereomers of (5′S)‐1‐[2′‐(2‐hydroxyethyl)tetrahydropyran‐5′‐yl]‐1H‐pyrimidine‐2,4‐dione and showed that the tetrahydropyranyl ring in the major 5′S,2′S‐isomer adopts the twist conformation. Copyright © 2002 John Wiley & Sons, Ltd.
1H, 13C and 15N NMR spectroscopic characterization of unexpected degradation products of the nifedipine analogue bis(2‐cyanoethyl) 2,6‐dimethyl‐4‐(2‐nitrophenyl)‐1,4‐dihydro‐3,5‐pyridinedicarboxylate
Authors: Gössnitzer Edith , Görlitzer Klaus , Baltrusch Hans J.
Published: August 2002

In the course of saponification experiments with bis(2‐cyanoethyl) 2,6‐dimethyl‐4‐(2‐nitrophenyl)‐1,4‐dihydro‐3,5‐pyridinedicarboxylate (1), an analogue of the calcium channel blocker nifedipine, three unexpected degradation products were isolated. The compounds were identified as 3‐(2‐acetamido‐1‐carboxy‐1‐propenyl)‐1‐hydroxy‐2‐indolecarboxylic acid (3), 9‐hydroxy‐1,3‐dimethyl‐β‐carboline‐4‐carboxylic acid (4) and 6‐hydroxy‐2,4‐dimethyl‐5‐oxo‐5,6‐dihydrobenzo[c][2,7]naphthyridine‐1‐carboxylic acid (6). The structures of these compounds were deduced from one‐ and two‐dimensional 1H, 13C and natural abundance 15N NMR experiments (1H,1H‐COSY, gs‐HSQC, gs‐HMBC, 15N gs‐HMBC), and corroborated by comparison of their NMR data with the respective data for structurally similar compounds. Copyright © 2002 John Wiley & Sons, Ltd.
1H, 13C and 31P NMR spectral analysis of monoalkyl (α‐anilinobenzyl)phosphonates and their dipalladium(II) metallocyclic complexes
Authors: Tušek‐Božić Ljerka , Lyčka Antonin
Published: August 2002

A 1H, 13C and 31P NMR study of monoethyl (HL1) and monobutyl (HL2) esters of (α‐anilinobenzyl)phosphonic acid and their metallocyclic dipalladium complexes (Pd2L4,L = L1, L2) in DMSO‐d6 was performed, based on 1D and 2D homo‐ and heteronuclear experiments including 1H,13C,31P,APT,1H–1H COSY, 1H–13C COSY, gs‐HMQC and gs‐HMBC NMR techniques. The results obtained are discussed with respect to those for some palladium(II) complexes reported for various anilinobenzylphosphonate derivatives. Copyright © 2002 John Wiley & Sons, Ltd.
15N NMR spectroscopy of 3‐substituted 5‐trichloromethyl‐1,2‐dimethyl‐1H‐pyrazolium chlorides
Authors: Martins Marcos A. P. , Pereira Claudio M. P. , Sinhorin Adilson P. , Rosa Adriano , Zimmermann Nilo E. K. , Bonacorso Helio G. , Zanatta Nilo
Published: August 2002

15N NMR data of a series of 3‐alkyl[aryl] substituted 5‐trichloromethyl‐1,2‐dimethyl‐1H‐pyrazolium chlorides (where the 3‐substituents are H, Me, Et, n‐Pr, n‐Bu, n‐Pe, n‐Hex, (CH2)5CO2Et, CH2Br, Ph and 4‐Br‐C6H4), are reported. The 15N substituent chemical shifts (SCS) parameters are determined and these data are compared with the 13C SCS values and data obtained by MO calculations. Copyright © 2002 John Wiley & Sons, Ltd.
NMDA receptor and neonatal hypoxic brain injury
Authors: Mishra Om P. , Fritz Karen I. , Delivoria‐Papadopoulos Maria
Published: August 2002

The NMDA‐type glutamate receptor is a predominant mediator of excitotoxicity in the immature brain due to overexpression of the receptor in the developing brain. Within the development period however, the extent of NMDA receptor mediated processes including hypoxia‐induced excitotoxicity may depend on the ontogeny of the NMDA receptor recognition and modulation sites, and subunits leading to altered function of the ion‐channel comples. The function of the receptor may be modified by intracellular mechanisms such as phosphorylation/dephosphorylation, nitration, and generation of free radicals including nitric oxide. The susceptibility of the developing brain to hypoxia depends on several factors: the lipid composition of the brain cell membrane; the rate of membrane lipid peroxidation and the status of anti‐oxidant defenses; the development and modulation of the NMDA receptor sites; the intracellular Ca2+ influx mechanisms; expression of apoptotic and antiapoptotic genes such as Bax and Bcl‐2; and the activation of initiator caspases and caspase‐3, the “executioner” of cell death. The developmental status of these cellular mechanisms and their response to hypoxia determine the fate of the hypoxic cell in the developing brain in the fetus and the newborn. MRDD Research Reviews 2001;7:249–253. © 2001 Wiley‐Liss, Inc.
Solenoidal array coils
Authors: Su Sunyu , Zou Mark Xueming , Murphy‐Boesch Joseph
Published: August 2002

New concepts are presented for inherent decoupling of multi‐element solenoidal arrays. First, an uneven counter‐rotational (UCR) coil is reported in which two counter‐rotational sections are wound unevenly, resulting in a quasi‐one‐peak sensitivity profile with a null‐B1 point. Adding a second solenoid element near the null‐B1 point forms an inherently‐decoupled solenoidal array. Unlike a sandwiched solenoidal array, an UCR solenoidal array allows for signal contribution at the center from both solenoid elements. Second, a double counter‐rotational (DCR) coil is presented in which two null‐B1 points are formed by having one counter‐rotational winding on each side of the coil. Two solenoidal elements can be added to form a solenoidal array. Finally, more solenoid elements can be added to the array provided that the added coil elements are DCR elements. These DCR coil elements can be used as building blocks for more complex solenoidal arrays. These concepts are illustrated using numerical simulations and tested using prototype coils. Magn Reson Med 47:794–799, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative analysis of adiabatic fast passage for steady laminar and turbulent flows
Authors: Gach H. Michael , Kam Anthony W. , Reid Eric D. , Talagala S. Lalith
Published: August 2002

Adiabatic fast passage (AFP) is used in noninvasive quantitative perfusion experiments to invert (or label) arterial spins. Continuous arterial spin labeling (CASL) experiments conducted in vivo often assume the inversion efficiency based on the labeling field and steady flow conditions, without direct verification. In practice, the labeling field used in CASL is often amplitude‐ and duty cycle‐limited due to hardware or specific absorption rate constraints. In this study, the effects of the labeling field amplitude and duty cycle, and flow dynamics on the inversion efficiency of AFP were examined under steady flow conditions in a saline flow phantom. The experimental results were in general agreement with models based on Zhernovoi's theory except at high labeling field amplitudes, when the spin inversion times are at least half of the duration of the labeling pulse. The nonlinear relation observed between the inversion efficiency and the labeling duty cycle implies that the practice of linear derating the inversion efficiency with the labeling duty cycle may be prone to significant error. A secondary finding was that the T1 of the flowing fluid could be calculated based on the flow dynamics after varying the flow rate. Magn Reson Med 47:709–719, 2002. © 2002 Wiley‐Liss, Inc.
Comparison of functional MRI image realignment tools using a computer‐generated phantom
Authors: Morgan Victoria L. , Pickens David R. , Hartmann Steven L. , Price Ronald R.
Published: August 2002

This study discusses the development of a computer‐generated phantom to compare the effects of image realignment programs on functional MRI (fMRI) pixel activation. The phantom is a whole‐head MRI volume with added random noise, activation, and motion. It allows simulation of realistic head motions with controlled areas of activation. Without motion, the phantom shows the effects of realignment on motion‐free data sets. Prior to realignment, the phantom illustrates some activation corruption due to motion. Finally, three widely used realignment packages are examined. The results showed that the most accurate algorithms are able to increase specificity through accurate realignment while maintaining sensitivity through effective resampling techniques. In fact, accurate realignment alone is not a powerful indicator of the most effective algorithm in terms of true activation. Magn Reson Med 46:510–514, 2001. © 2001 Wiley‐Liss, Inc.
Study of evolution of shear band systems in sand retained by flexible wall
Authors: Leśniewska Danuta , Mróz Zenon
Published: August 2002

The present paper is concerned with the study of the evolution of regular patterns of shear bands observed experimentally (cf. Milligan, 1974), and provides an extension of the previous work published by the same authors. The purpose of this paper is to present an improved version of a simple theoretical model, derived basically from a classical equilibrium of the Coulomb wedge. This model constitutes a modified version of an extension of the classical Coulomb wedge analysis by assuming that soil parameters are varying during the deformation process and the initial configuration at which limit equilibrium occurs evolves toward a new equilibrium configuration. The application of the model in the analysis of shear band pattern observed in dredged model tests on cantilever walls provided realistic simulation of consecutive shear band formation. Copyright © 2001 John Wiley & Sons, Ltd.
A decision support system for telecommunications
Authors: Flynn Paul , Curran Kevin , Lunney Tom
Published: August 2002

We have built a Decision Support System (DSS) which can to aid strategic management within the industry in making vital decisions in relation to Customer and Network profiles. This enables managers in the respective areas within the industry to fully utilise the vast amounts of data available to make projections and decisions in relation to utilisation of valuable resources. Copyright © 2002 John Wiley & Sons, Ltd.
Muscle‐derived neurotrophin‐3 reduces injury‐induced proprioceptive degeneration in neonatal mice
Authors: Wright D. E. , Williams J. M. , McDonald J. T. , Carlsten J. A. , Taylor M. D.
Published: August 2002

During perinatal development, proprioceptive muscle afferents are quite sensitive to nerve injury. Here, we have used transgenic mice that overexpress neurotrophin‐3 (NT‐3) in skeletal muscle (myo/NT‐3 mice) to explore whether NT‐3 plays a neuroprotective role for perinatal muscle afferents following nerve injury. Measurements of NT‐3 mRNA using RT‐PCR revealed that levels of endogenous NT‐3 mRNA in wild‐type muscles remained constant during the first postnatal week following nerve crush or nerve section on postnatal day (PN) 1. In comparison, myo/NT‐3 mice had significantly elevated levels of NT‐3 mRNA that were maintained or increased following injury. To assess whether muscle‐derived NT‐3 could prevent injury‐induced neuronal death, neuron survival in the DRG was analyzed in mice 5 days after sciatic nerve crush on PN3. Retrograde prelabeling of muscle afferents and parvalbumin immunocytochemistry both revealed that overexpression of NT‐3 in muscle significantly reduced neuronal loss following injury. Similar neuroprotective effects of NT‐3 were observed in wild‐type mice injected with exogenous NT‐3 in the gastrocnemius muscles. To test whether NT‐3 could prevent muscle spindle degeneration, spindle number and morphology were assessed 3 weeks after sciatic nerve crush or section on PN1. No spindles were present in either wildtype or myo/NT‐3 muscles after nerve section, demonstrating that NT‐3 overexpression cannot maintain spindles following complete denervation. Moreover, NT‐3 overexpression could not prevent moderate spindle loss in muscle and did not stimulate new spindle formation following nerve crush. Our results demonstrate that in addition to its early actions on sensory neuron generation and naturally occurring cell death, NT‐3 has important neuroprotective effects on muscle afferents during postnatal development. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 198–208, 2002; DOI 10.1002/neu.10024
Septum volume and food‐storing behavior are related in parids
Authors: Shiflett Michael W. , Gould Kristy L. , Smulders Tom V. , DeVoogd Timothy J.
Published: August 2002

The hippocampal formation (HF) of food‐storing birds is larger than non‐storing species, and the size of the HF in food‐storing Black‐Capped Chickadees (Poecile atricapillus) varies seasonally. We examined whether the volume of the septum, a medial forebrain structure that shares reciprocal connections with the HF, demonstrates the same species and seasonal variation as has been shown in the HF. We compared septum volume in three parid species; non‐storing Blue Tits (Parus caeruleus) and Great Tits (Parus major), and food‐storing Black‐Capped Chickadees. We found the relative septum volume to be larger in chickadees than in the non‐storing species. We also compared septum and nucleus of the diagonal band (NDB) volume of Black‐Capped Chickadees at different times of the year. We found that the relative septum volume varies seasonally in food‐storing birds. The volume of the NDB does not vary seasonally. Due to the observed species and seasonal variation, the septum, like the hippocampal formation of food‐storing birds, may be specialized for some aspects of food‐storing and spatial memory. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 215–222, 2002
Stability analysis of cylindrical shells using refined non‐conforming rectangular cylindrical shell elements
Authors: Shaoyan Zhang , Cheung Y. K. , Wanji Chen
Published: August 2002

The accuracy of stability analysis depends on the accuracy of both the element stiffness matrix and geometry stiffness matrix. Therefore, when carrying out the stability analysis of thin cylindrical shells using the finite element methods will require, firstly, a refined non‐conforming rectangular curved cylindrical shell element RCSR4 is proposed according to the refined non‐conforming FE method, in which both the C1 and C0 weak continuity conditions are satisfied and as a result, can ensure the convergence of computation. At the same time, a refined geometrical stiffness matrix is introduced to replace the standard consistent geometrical stiffness matrix. Simple expressions of the refined constant strain matrices with adjustable constants are introduced with respect to the weak continuity conditions. Numerical examples are presented to show that the present method can indeed improve the performance and the accuracy in stability analysis. Copyright © 2001 John Wiley & Sons, Ltd.
Linear stability analysis and fourth‐order approximations at first time level for the two space dimensional mildly quasi‐linear hyperbolic equations
Authors: Mohanty R. K. , Arora Urvashi , Jain M. K.
Published: August 2002

In 1996, Mohanty et al. [1] presented a fourth‐order finite difference solution of a two space dimensional nonlinear hyperbolic equation with Dirichlet boundary conditions. In 1998, Mohanty et al. [2] discussed a fourth‐order approximation at first time level for the numerical solution of the one space dimensional hyperbolic equation. In both the cases, they have discussed the stability analysis for the linear hyperbolic equation having first‐order space derivative terms. Recently, Mohanty et al. [3] have developed fourth‐order difference formulas for the three space dimensional quasi‐linear hyperbolic equations and obtained fourth‐order approximation at first time level. In this article, we extend our strategy for solving the two space dimensional quasi‐linear hyperbolic equation. An operator splitting method for a linear hyperbolic equation having a time derivative term is proposed. Linear stability analysis and fourth‐order approximation at first time level for the two space dimensional quasi‐linear hyperbolic equation are also discussed. The results of the numerical experiments are compared with the exact solution. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17: 607–618, 2001
Dietary supplementation with conjugated linoleic acid does not improve nutritional status of tumor‐bearing rats*
Authors: McCarthy‐Beckett Donna O.
Published: August 2002

Tumor necrosis factor–α (TNF) is an immunoregulatory cytokine that plays a major role in tumor‐induced anorexia and weight loss. Conjugated linoleic acids (CLA) are naturally occurring isomers of linoleic acid that, when added to the diet, improve food intake and body weight in mice injected with TNF. The purpose of the present study was to examine the effects of a diet supplemented with 0.5% CLA on the nutritional status of rats implanted with the Morris 7777 hepatoma. Body weight, food intake, serum levels of insulin‐like growth factor, and splenocyte synthesis of TNF were not different in tumor‐bearing animals fed CLA versus the control diet. However, insulin levels were increased in both tumor‐bearing and control animals given CLA. The 0.5% CLA did not improve the nutritional status nor alter TNF synthesis in hypophagic tumor‐bearing rats. The biological significance of increased insulin levels in animals given CLA remains to be determined. © 2002 John Wiley & Sons, Res Nurs Health 25:49–57, 2002.
Polynomial matrix solution of H2 optimal control problem for state‐space systems
Authors: Grimble M. J.
Published: August 2002

A polynomial matrix solution to the H2 output feedback optimal control problems is obtained for systems represented in state‐equation form. The proof does not invoke the separation principle but is obtained in the z‐domain. The cost function includes weighted states, which allows the so‐called standard system model problem to be solved. This encompasses the class of inferential control problems. The results also enable the two‐degree‐of‐freedom optimal control solution properties to be explored. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and characterization of a novel soluble reactive ladder‐like polysilsesquioxane with side‐chain 2‐(4‐chloromethyl phenyl) ethyl groups
Authors: Liu Chunqing , Liu Yang , Xie Ping , Dai Daorong , Zhang Rongben
Published: August 2002

A new kind of soluble structure‐ordered ladder‐like polysilsesquioxane with reactive side‐chain 2‐(4‐chloromethyl phenyl) ethyl groups (L) was first synthesized by stepwise coupling polymerization. The monomer, 2‐(4‐chloromethyl phenyl) ethyltrichlorosilane (M), was synthesized successfully by hydrosilylation reaction with dicyclopentadienylplatinum(II) chloride (Cp2PtCl2) ­catalyst. Monomer and polymer structures were characterized by FT‐IR, 1H‐NMR, 13C‐NMR, 29Si‐NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vapor pressure osmometry (VPO) and X‐ray diffraction (XRD). This novel reactive ladder‐like polymer has promise potential applications as initiator for atom transfer radical polymerization, and as precursor for a variety of advanced functional polymers. Copyright © 2001 John Wiley & Sons, Ltd.
Thermal stability study of conductive polyaniline/polyimide blend films on their conductivity and ESR measurement
Authors: Han Moon Gyu , Byun Sung Woen , Im Seung Soon
Published: August 2002

Conductivity stability at thermal environment of conductive polyaniline‐complexes/polyimide (PANI‐complexes/PI) blends, which were doped by camphorsulfonic acid (CSA) and dodecylbenzenesulfonic acid (DBSA), respectively, were investigated by conductivity measurements, electron spin resonance (ESR) spectra, differential and scanning thermometer (DSC). In the conversion process of PANI/Polyamic acid (PAA) to PANI/PI, the blend endeavored some kinds of alteration such as decomplexation of moisture and solvent, dissociation of dopant, crosslinking of PANI chain, and the imidization of PAA chain. PANI‐DBSA/PI showed higher thermal stability of conductivity than PANI‐CSA/PI, and both samples showed nearly linear decay of conductivity with increasing temperature showing greatly enhancement of conductivity stability. When they were exposed at near or over glass transition temperature, the conductivity decay became faster. The conductivity stability at base environment was also higher for PANI‐DBSA/PI due to difficulty in accessing of hydroxyl ion to PANI, which were resulted from dopant. DBSA‐doped blends showed increased polaron mobility and concentration at relatively high temperature, which led to extremely higher conductivity and its stability at high temperature. Copyright © 2002 John Wiley & Sons, Ltd.
Poly(silylene)s: charge carrier photogeneration and transport
Authors: Nešpůrek S. , Eckhardt A.
Published: August 2002

An Erratum has been published for this article in Polymers for Advanced Technologies 12(10)2001, 603.

Poly(diorganylsilylene)s can be excited within the framework of Si bonds in the polymer backbone as well as within a side group skeleton. An electron transfer from the main chain to a side group or an interchain electron transfer is necessary to form a quasi‐stable ion‐pair. Dissociation of the ion‐pair in the external electric field can be described in terms of the Onsager theory of geminate recombination. The charge carrier transport proceeds predominantly along σ‐delocalized Si backbone with participation of interchain hopping and polaron formation. A model of disordered polarons seems to be adequate to describe the charge carrier transport properties. Copyright © 2001 John Wiley & Sons, Ltd.
Successful intrauterine shunting of a sacrococcygeal teratoma (SCT) causing fetal bladder obstruction
Authors: Jouannic Jean‐Marie , Dommergues Marc , Auber Frédéric , Bessis Roger , Nihoul‐Fekete Claire , Dumez Yves
Published: August 2002

We report a case of a sacrococcygeal teratoma (SCT) diagnosed at 22 weeks with a substantial intrapelvic cystic extension leading to bladder outlet obstruction and hydronephrosis at 27 weeks. Prenatal percutaneous shunting of the cystic teratoma was performed at 28 weeks to avoid prolonged fetal pelvic compression by the tumour that could have adverse effects by stretching the pelvic plexus and sacral nerves. Urinary dilatation resolved completely after shunting and a 3880 g baby girl was delivered at 39 weeks. The potential benefits of in utero shunting to avoid urological complications of SCTs with intrapelvic extension are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Multicolour spectral karyotyping for complex chromosomal rearrangements in repeated abortion or congenital anomalies
Authors: Tanemura Mitsuyo , Suzumori Kaoru , Nishikawa Naomi , Ishihara Yoshimori
Published: August 2002

Advances in molecular cytogenetics, especially the technique of fluorescence in situ hybridization (FISH), have allowed more precise definition of chromosomal structures, which are difficult to identify using conventional G‐banding. Recently, a novel approach based on hybridization of 24 fluorescent‐labelled chromosome painting probes was developed, termed spectral karyotyping (SKY), which allows the simultaneous and differential colour display of all human chromosomes. We have used SKY to identify not only five parental complex translocation carriers but also minute chromosome rearrangements in the fetus. Here, we concentrate attention on the clinical application of SKY for prenatal diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.
Magnetic‐activated cell sorting (MACS) significantly decreases the hybridization efficiency of fluorescence in situ hybridization (FISH)
Authors: Kuo Pao‐Lin , Guo How‐Ran
Published: August 2002

Fetal cells were enriched from maternal blood using density gradient centrifugation of Histopaque followed by magnetic‐activated cell sorting (MACS) to select CD71‐positive cells. For each specimen, cells partially purified by Histopaque were split into equal portions, and each portion was subjected to purification by MACS in parallel. Cells before and after MACS were subjected to dual‐color fluorescence in situ hybridization (FISH) analysis with X‐ and Y‐chromosome‐specific probes. We found that the hybridization rates were decreased by approximately 10% after MACS based on duplicated analysis for each sample. Copyright © 2001 John Wiley & Sons, Ltd.
Adult height in women with childhood asthma – a population‐based study
Authors: Norjavaara Ensio , de Verdier Maria Gerhardsson , Lindmark Bertil
Published: August 2002

Purpose

To study adult height in children that grew up with asthma before inhaled steroids became first‐line therapy.

Methods

Data from the Swedish Medical Birth Register (self‐reported asthma) and the Hospital Discharge Register (first hospitalization for asthma) were used, to compare adult height for asthmatic and non‐asthmatic pregnant women. The analysis was restricted to women in their first full‐term pregnancy, born in Sweden between 1960–1974 and of Swedish citizenship.

Results

The mean height of all the women in the study population was 166.7 cm (SD = 8.8, n = 287,750) and of the women who reported asthma 166.5 cm (SD = 6.1, n = 13,059, p < 0.01). The mean height of women first hospitalized because of asthma at age 0–8 years was 165.5 cm (SD = 5.9 cm, n = 555, p < 0.01). Among the asthmatic women, there was no skew distribution of heights.

Conclusions

Girls with moderate to severe childhood asthma who grew up before inhaled glucocorticosteroids became first‐line therapy attained 0.7–1.2 cm lower adult height. The differences in height, while of statistical relevance, are not clinically relevant. Copyright © 2001 John Wiley & Sons, Ltd.
pH‐independent hydrolysis of 4‐nitrophenyl 2,2‐dichloropropionate in aqueous micellar solutions: relative contributions of hydrophobic and electrostatic interactions
Authors: EI Seoud Omar A. , Ruasse Marie‐Françoise , Possidonio Shirley
Published: August 2002

The pH‐independent hydrolysis of 4‐nitrophenyl 2,2‐dichloropropionate (NPDCP) in the presence of aqueous micelles of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, alkyltrimethylammonium chlorides, alkyldimethylbenzylammonium chlorides (alkyl = cetyl and dodecyl) and polyoxyethylene(9) nonylphenyl ether was studied spectrophotometrically. The observed rate constants, kobs, decrease in the following order: bulk water >cationic micelles >anionic micelles >non‐ionic micelles. This order is different from that observed for pH‐independent hydrolysis of 4‐nitrophenyl chloroformate (NPCF), whose reaction is faster in cationic micelles than in bulk water. A proton NMR study on solubilization of a model ester, 4‐nitrophenyl 2‐chloropropionate, showed that the methylene groups in the middle of the surfactant hydrophobic chain are most affected by the solubilizate. Lower polarity and high ionic strength of interfacial water decrease the rates of hydrolysis of both NPCF and NPDCP, but the fraction of the former ester that diffuses to the interface is probably higher than that of the latter. Therefore, whereas the (negatively charged) transition state of NPCF is stabilized by cationic interfaces and destabilized by anionic interfaces, that of NPDCP is negligibly affected by ionic interfaces, which explains the observed rate retardation by all ionic micelles. Calculated activation parameters corroborate our explanation. Copyright © 2001 John Wiley & Sons, Ltd.
Z/E isomerization of poly‐para‐phenylenevinylene model compounds
Authors: Lange Frank J. , Leuze Meret , Hanack Michael
Published: August 2002

The poly‐para‐phenylenevinylene (PPV) model compound 1 with cyano groups on the vinylene moieties and 2‐ethylhexyloxy chains on the central phenylene unit has been synthesized by Knoevenagel condensation of 1,4‐bis(cyanomethyl)‐2,5‐bis(2‐ethylhexyloxy)benzene and benzaldehyde. The only isomer that was obtained has been identified to have the Z,Z configuration. UV irradiation of the Z,Z isomer 1a in solution with a medium‐pressure mercury lamp gave a mixture of all three possible isomers (Z,Z, Z,E and E,E; 1a, 1b and 1c respectively). The isomers were separated by column chromatography and identified spectroscopically. Electrochemical studies and fluorescence emission spectra of 1a and 1c are reported. The substituted PPVs 2, 3 and 4 have been synthesized and their absorption and emission spectra before and after UV irradiation are compared. Copyright © 2001 John Wiley & Sons, Ltd.
Infrared intensities of benzene derivatives as a measure of the substituent resonance effect
Authors: Palát Karel , Waisser Karel , Exner Otto
Published: August 2002

Infrared spectra of 39 benzene mono‐derivatives were recorded in the region 1000–1800 cm−1 and the intensities of the bands ν16a and ν16b were determined by computer separation. The intensities correlated with the squared resonance substituent constants σRo as found by Katritzky and co‐workers, but band separation does not represent any essential improvement compared with the earlier simpler technique. With substituents including an NH2 group, there is still an interference with the NH2 scissoring deformation band: in these cases deuteration is more effective than band separation. Several new constants σRo were determined spectroscopically for substituents of interest in pharmacology and these constants were also calculated by a quantum chemical model. The latter procedure seems to be most efficient and reasonably reliable for calculating new σRo constants; the only problem may be with the conformation in the case of axially unsymmetrical substituents. Copyright © 2001 John Wiley & Sons, Ltd.
Reaction of glycidyl phenyl ether with imines: A model study of latent hardeners of epoxy resins in the presence of water
Authors: Suzuki Kentarou , Matsu‐Ura Nobuki , Horii Hisakazu , Sugita Yuko , Sanda Fumio , Endo Takeshi
Published: August 2002

The hydrolyses of several imines and their reactions with glycidyl phenyl ether were examined under highly humid conditions as a model study for the development of water‐initiated hardeners for epoxy resins. Diethyl ketone‐based imines were hydrolyzed more efficiently than methyl isobutyl ketone‐based imines. The reactions of glycidyl phenyl ether with the imines depended on their hydrolysis rates and the basicity of the amines generated from them. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 971–975, 2002
Iron‐catalyzed living radical polymerization of acrylates: Iodide‐based initiating systems and block and random copolymerizations
Authors: Onishi Isamu , Baek Kyung‐Youl , Kotani Yuzo , Kamigaito Masami , Sawamoto Mitsuo
Published: August 2002

A half‐metallocene iron iodide complex [Fe(Cp)I(CO)2] induced living radical polymerization of methyl acrylate (MA) in conjunction with an iodide initiator [(CH3)2C(CO2Et)I, 1] and Al(Oi‐Pr)3 to give polymers of controlled molecular weights and narrow molecular weight distributions (MWDs) (Mw/Mn < 1.2). With the use of chloride and bromide initiators, the MWDs were broader, whereas the molecular weights were similarly controlled. Other acrylates such as n‐butyl acrylate (nBA) and tert‐butyl acrylate (tBA) can be polymerized with 1/Fe(Cp)I(CO)2 in the presence of Ti(Oi‐Pr)4 and Al(Oi‐Pr)3, respectively, to give living polymers. The 1/Fe(Cp)I(CO)2 initiating system is applicable for the synthesis of block and random copolymers of acrylates (MA, nBA, and tBA) and styrene of controlled molecular weights and narrow MWDs (Mw/Mn = 1.2–1.3). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2033–2043, 2002
Synthesis and characterization of soluble fluorine‐containing polyimides based on 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene
Authors: Xie K. , Zhang S. Y. , Liu J. G. , He M. H. , Yang S. Y.
Published: August 2002

The synthesis and properties of a class of soluble fluorine‐containing aromatic polyimides are described. Substituents of trifluoromethyl groups on the aromatic rings of paralinked aromatic ether diamine conferred the polymer prepared thereof with enhanced solubility, low‐moisture absorption, and low dielectric constants. The polyimides also exhibited exceptional thermal stability, good mechanical properties, and excellent hygrothermal resistance. These outstanding combined features ensure the polymers are desirable candidate materials for advanced microelectronics applications. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2581–2590, 2001
Adhesion of grafted polyethylene to an ethylene/vinyl alcohol copolymer
Authors: Guiu Antoine , Shanahan Martin E. R.
Published: August 2002

Modern developments in polymer technology include the use of multimaterials. Two or more polymers are fashioned together to produce a composite with a desired combination of properties. However, the success of such materials depends on the quality of the adhesion between the various phases. In this study, we considered the adhesion between a grafted polyethylene and an ethylene/vinyl alcohol copolymer with various peel test geometries. The principal, L‐peel, test was employed with various peel angles. Using elastoplastic analysis, we found that the effective peel energy, increasing with the peel angle, may be corrected for bulk energy dissipation, leading to a relatively constant local value for intrinsic peel resistance, independent of geometry. Effects of the peel rate and temperature may be combined to give a master curve, apparently a novelty for thermoplastics, although well known for elastomers. At a (corrected) peel rate, a jump in adhesion energy, apparently related to a change to a stick–slip peel regime, was observed. This jump appeared to be absent for some other peel geometries. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2843–2851, 2001
Properties of amphoteric polyurethane waterborne dispersions. I. Dependence on pH value in salt‐free media
Authors: Dong Anjie , Hou Guoling , Wang Yuxia , Sun Duoxian
Published: August 2002

The characteristics of amphoteric, amphiphilic polyurethanes (APUs) that depend on the pH value of the medium were studied. The dependence of the particle size and distribution as well as absorbency of the APU waterborne dispersions on the pH value of the medium were investigated by photon correlation spectroscopy and spectrophotometry methods, respectively. The results indicated that the pH dependence of the properties of APU aqueous dispersions can be characterized by two static balance states, a dynamic equilibrium state and two turbulent states with a changing pH of the medium. This can be attributed to the conformation changes of APU macromolecules as a result of the interaction between APU macromolecules affected by the ionization degree of the acid or base groups pendent on APU macromolecular chains. A reorganization process of APU macromolecules in its aqueous dispersion took place when the pH of the system was changed from basic to acidic or from acidic to basic. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 972–979, 2002
Using carbon nanotubes to detect polymer transitions
Authors: Zhao Qing , Wood Jonathan R. , Wagner H. Daniel
Published: August 2002

Raman spectral shifts of single‐wall carbon nanotubes embedded in polymer systems were used to measure transitions in polymers. Glass‐transition temperatures and secondary transitions were observed, and Raman spectroscopic data were compared with dynamic mechanical tests for a thermosetting and a thermoplastic polymer. The data confirm that the Raman spectral response of carbon nanotubes embedded in polymers is sensitive to polymer transitions. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1492–1495, 2001
Assessment of the diffusional behavior of polystyrene sulfonates in the dilute regime by hollow‐fiber flow field flow fractionation
Authors: Bruijnsvoort M. Van , Tijssen R. , Kok W. Th.
Published: August 2002

We applied flow field flow fractionation in a ceramic tubular membrane to study the diffusional behavior of sodium polystyrene sulfonate (NaPSS) as a function of salt and polyelectrolyte concentrations in the dilute concentration regime. NaPSS standards were fractionated in an aqueous carrier liquid with salt concentrations of 1–100 mmol L−1 and injected amounts of 0.2–20 μg. A sharp increase in the apparent diffusion coefficients, due to peak overloading, occurred at a critical polyelectrolyte concentration at the accumulation wall. A model has been developed that compares repulsive electrostatic interactions, calculated from the Derjaguin–Landau–Verweij–Overbeek theory, to the thermal energy. It was found that the observed critical concentration approximated the concentration of a closely packed lattice of hard spheres within an order of magnitude. The critical concentration appeared to be dependent on the salt concentration, but the influence of the molecular mass was less clear. Expressions for the migration velocity in overloaded channels were derived and confirmed experimentally for the two lowest molecular masses. Deviations occurred for high molecular mass NaPSS, possibly because of mutual attraction. These experiments confirmed the observations made by small‐angle neutron scattering and dynamic light scattering that the ordering of polyelectrolytes already occurred in the dilute regime. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1756–1765, 2001
Inadequate asthma treatment practices and noncompliance in Israel*
Authors: Eshel Gideon , Raviv Ravit , Ben‐Abraham Ron , Barr Joseph , Berkovitch Mati , Efrati Ori , Vardi Amir , Barzilay Zohar , Paret Gideon
Published: August 2002

Childhood asthma morbidity and mortality are increasing despite improvements in asthma therapy. The changes over the past decade in the guidelines for treatment of children with severe asthma have led to a reduction in admissions and readmissions to the pediatric intensive care unit (PICU). The Israeli medical infrastructure is exemplary in its capability of extending appropriate medical services to its entire population. Our objective was to look at the background of preventive maintenance treatment and treatment during an acute episode in children admitted to PICUs with severe asthma, and to identify areas that could be targeted for change. A 5‐year retrospective chart audit on acute asthma admissions was conducted in two PICUs of general community hospitals representative of the provision of medical care in Israel. The prehospitalization preventive management and acute treatment prior to PICU admission were evaluated, and the number of admissions and readmissions was recorded.

The index admission was the first episode of acute asthma for only 3% of the children: 25% of patients required readmission, and 15% of these to the PICU. In spite of a proven history of acute exacerbations of the disease, only 60% were on continuous treatment between attacks, and 29% of them had abruptly discontinued treatment, most of them shortly before the onset of the index attack. Inhaled steroids were used as maintenance and preventive treatment by less than one‐third of the children, with the other two‐thirds receiving mainly beta‐2 agonists drugs.

In conclusion, an unacceptably large proportion of asthmatic children do not receive the recommended maintenance and preventive treatment because of poor compliance, lack of education, or insufficient healthcare provision. This has probably led to avoidable recurrences of acute asthma exacerbations and unnecessary use of PICU facilities. These findings suggest that steps for implementing recommended guidelines and an educational program are needed. Pediatr Pulmonol. 2002; 33:85–89. © 2002 Wiley‐Liss, Inc.