bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractIn 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

AbstractTumor 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

AbstractA 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

AbstractA 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

AbstractConductivity 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

AbstractAn 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

AbstractWe 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

AbstractAdvances 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

AbstractFetal 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

AbstractPurposeTo study adult height in children that grew up with asthma before inhaled steroids became first‐line therapy.MethodsData 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.ResultsThe 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.ConclusionsGirls 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

AbstractThe 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

AbstractThe 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

AbstractInfrared 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

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractModern 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

AbstractThe 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

AbstractRaman 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

AbstractWe 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