bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluid mechanics of a Mach 7-12, electron-beam driven, missile-scale hypersonic wind tunnel: Modeling and predictions
Authors: Girgis I. G. , Brown G. L. , Miles R. B. , Lipinski R. J.
Published: October 2002

Models of increasing complexity have been developed for the design and simulation of the axisymmetric inviscid fluid mechanics and energy addition of an electron-beam driven hypersonic wind tunnel for missile-scale testing and development. The principal target has been a Mach-12 capability at altitudes of approximately 25 km and above with a test section of 1.3 m. Also, results for lower Mach numbers at lower altitudes down to Mach-7 at 2 km have been obtained. The fully coupled e-beam and Euler flow simulation shows that with a magnetically guided, 3 MeV e-beam and a nozzle geometry determined from the solution to an optimization problem, shock waves can be eliminated notwithstanding the very high radiative power (200 MW) that is deposited into the core flow (away from the boundary layer). While there remain many issues to be resolved, we have not yet found an intrinsic problem with either the concept or its application to such long run time, missile-scale, facilities.
Vortex control of bifurcating jets: A numerical study
Authors: da Silva Carlos B. , Métais Olivier
Published: October 2002

Direct and large-eddy simulations (DNS/LES) are performed to analyze the vortex dynamics and the statistics of bifurcating jets. The Reynolds number ranges from ReD=1.5×103 to ReD=5.0×104. An active control of the inlet conditions of a spatially evolving round jet is performed with the aim of favoring the jet spreading in one particular spatial direction, thus creating a bifurcating jet. Three different types of forcing, based on the information provided by a LES of a natural (unforced) jet, are superimposed to the jet inlet in order to cause its bifurcation. The different forcing types mimic the forcing methods used in experimental bifurcating jets (Lee and Reynolds, Parekh et al., Suzuki et al.), but using excitations with relatively low amplitudes, which could be used in real industrial applications. The three-dimensional coherent structures resulting from each specific forcing are analyzed in detail and their impact on the statistical behavior of bifurcating jets is explained. In particular we focus on the influence of the forcing frequency and of the Reynolds number on the jet control efficiency. Analysis of the coherent vortex dynamics shows that an inlet excitation which combines an axisymmetric excitation at the preferred frequency and a so-called flapping excitation at the subharmonic frequency is the most efficient strategy for jet control, even at high Reynolds numbers.
Three-dimensional instability and state selection in an oscillatory axisymmetric swirling flow
Authors: Blackburn H. M.
Published: October 2002

Previous studies of the flow created inside a cylindrical cavity (radius R, height H) of fluid by a single rotating end wall have shown that over a range of cylinder aspect ratios 1.6≲H/R≲2.8, the first unsteady flows to bifurcate with increasing Reynolds number retain axisymmetry, and subsequent bifurcations break axisymmetry to give solutions with modulated rotating wave (MRW) states. The underlying axisymmetric components of these MRW flows are nearly indistinguishable from corresponding axisymmetric flows at the same Reynolds numbers. Of the three solution branches so far identified for this flow at H/R=2.5, only one both supports MRWs and has a simple limit-cycle underlying axisymmetric flow. Here, we carry out three-dimensional Floquet stability analysis of this branch of axisymmetric solutions and demonstrate that only a subset of the linearly unstable MRWs are observed asymptotically at large times for full Navier–Stokes solutions. Stability analysis of the time-average axisymmetric flow shows rotating wave (RW) instabilities that are in many ways similar to the MRW Floquet modes. The orientation of the vorticity of the RW and MRW structures implies that they are unlikely to originate as centrifugal instabilities, while simplified inviscid shear flow stability analysis of the time-average velocity profiles suggests instead that they arise as a result of inflectional instability of the swirling wall-jet flow contained by the cylindrical walls of the cavity.
Electronic structure and chemical bonding of divanadium-oxide clusters (V2Ox, x=3–7) from anion photoelectron spectroscopy
Authors: Zhai Hua-Jin , Wang Lai-Sheng
Published: October 2002

We report a photoelectron spectroscopic investigation of a series of divanadium-oxide clusters V2Ox− (x=3–7). Well-resolved spectra were obtained at three photon energies (355, 266, and 193 nm), revealing the structural and electronic evolution as the number of oxygen atoms increases in the cluster series. A behavior of sequential oxidation was observed in V2Ox− for x up to 5: low binding energy features with primarily V 3d characters were disappearing in numbers and simultaneously shifting to higher binding energies with increasing oxygen content as a result of V→O charge transfers. Finally, for V2O6− and V2O7−, the photoelectron spectra exhibit very-high-binding-energy features characteristic of O 2p characters. Vibrationally resolved spectra were obtained for the ground-state features of V2O4− and V2O6−, with a spacing of 1090 cm−1 (V2O4) and 800 cm−1 (V2O6), which are assigned to V–O stretching vibrations. Electron affinities are reported for V2O3 to V2O7, and those of 5.61 eV for V2O6 and 5.38 eV for V2O7 are among the highest electronic affinities ever reported. The data are compared with previous theoretical calculations.
The competition between hydrogen bonding and chemical change in carbohydrate nanoparticles
Authors: Jetzki Martin , Signorell Ruth
Published: October 2002

Broad band Fourier transform infrared spectroscopy was used to study the competition between hydrogen bonding and conformational and chemical changes in molecular nanoparticles. Particles of small carbohydrates (dihydroxyacetone, glyceraldehyde, fructose, and glucose) with sizes between 20 and 100 nm served as model systems. The variation of the preparation conditions allowed to control the chemical composition of the particles. For dihydroxyacetone, the particle generation in an electrospray is accompanied by the formation of intermolecular hemiketals. In contrast, particles generated directly from the vapor phase in a collisional cooling cell consist exclusively of the monomeric form. Quantum chemical simulations demonstrate that conformational changes upon particle formation can be understood to a good approximation on a molecular level. In contrast to that, the characteristic band shape observed for all carbohydrates studied is determined by the interaction of the whole ensemble of OH-oscillators. These contributions could be described within a continuum model.
Nuclear-excited Feshbach resonance in the Ar(3P)+CH3Br Penning ionization reaction under orientation and velocity specified collisions
Authors: Okada S. , Ohoyama H. , Kasai T.
Published: October 2002

The collision-energy and orientation-angle-resolved Penning ionization cross section was determined for the Ar(3P)+CH3Br reaction by using an oriented beam and a time-of-flight measurement. A remarkable resonance-type structure in the Penning ionization cross section is recognized in the collision energy dependence at fixed molecular orientations, which is very similar to the one we previously observed in the Ar(3P)+CH3Cl reaction. This resonance-type structure could be interpreted as a new type nuclear-excited Feshbach resonance where the branching to competitive neutral dissociation channel is enhanced due to the formation of vibrationally excited CH3Br Rydberg states.
Diffusion-limited reaction in the presence of random fields and transition rates
Authors: Lee Jae Woo
Published: October 2002

The diffusion-limited reaction was studied on a one-dimensional lattice in the presence of random fields and transition rates using Monte Carlo simulations. In the case of transition rates the hopping probabilities at a site are distributed according to the power law p(y)=νyν−1 with 0<ν⩽1 and 0<y⩽1. The density of the reactants decays according to a power-law, C(t)∼t−α(ν) for A+A→0 and A+B→0 annihilation reactions. The exponent α(ν) depends on the disorder exponent ν. For A+A→0, we found α(ν)=ν/(1+ν). For A+B→0, we observed α=0.25 at ν>0.4 and α decreases monotonically for ν<0.4. In the case of the random fields the density decays according to C(t)∼[b(E)/log(t)]2 regardless of the strength of the random fields E for A+A→0 and A+A→A reactions, where b(E)∼log[(1+E)/(1−E)]. The diffusion-limited coagulation A+A→A belongs to the same universality class as the A+A→0 reaction under the random fields. For A+B→0 annihilations we observe that the density decays according to C(t)∼b(E)/log(t) in the presence of the random fields.
Dielectric properties of sol–gel-derived MgO:Ba0.5Sr0.5TiO3 thin-film composites
Authors: Jain M. , Majumder S. B. , Katiyar R. S. , Agrawal D. C. , Bhalla A. S.
Published: October 2002

Alternate layer deposition of heterostructured magnesium oxide (MgO):barium strontium titanate (BST) thin films is demonstrated to be an approach to synthesize dielectric films with a higher figure of merit for microwave dielectric applications. The dielectric constant and the dielectric tunability are modified by MgO insertion. The dramatic reduction in the dielectric loss tangent effectively increased the figure of merit of the heterostructured thin films as compared to the pure BST films. The significant reduction in the dielectric loss tangent values has been attributed to the minute solid solubility of MgO in the BST lattice and the induced microstructural modifications induced by the MgO layers in thin films.
Electroluminescence at 1.54 μm in Er-doped Si nanocluster-based devices
Authors: Iacona F. , Pacifici D. , Irrera A. , Miritello M. , Franzò G. , Priolo F. , Sanfilippo D. , Di Stefano G. , Fallica P. G.
Published: October 2002

The electroluminescence (EL) properties of Er-doped Si nanoclusters (NC) embedded in metal–oxide–semiconductor devices are investigated. Due to the presence of Si NC dispersed in the SiO2 matrix, an efficient carrier injection occurs and Er is excited, producing an intense 1.54 μm room temperature EL. The EL properties as a function of the current density, temperature, and time have been studied in detail. We have also estimated the excitation cross section for Er under electrical pumping, finding a value of ∼1×10−14 cm2. This value is two orders of magnitude higher than the effective excitation cross section of Er ions through Si NC under optical pumping. In fact, quantum efficiencies of ∼1% are obtained at room temperature in these devices.
The exponential of the curl: Application to Maxwell fields
Authors: Power E. A. , Thirunamachandran T.
Published: October 2002

The operation of the exponential of the curl on a general vector field is studied. It is nonlocal, and it is shown that the resultant field may be written as the sum of integrals over all space. The formal solutions of the time-dependent Maxwell’s equations for an arbitrary current density are first written in terms of the curl, and explicit expressions for the electric and magnetic fields are given in terms of the source current densities loaded with these kernels. This method of deriving the fields obviates the introduction of electromagnetic potentials. The well-known expressions for the fields are derived for a fixed oscillating dipole and a charge in arbitrary motion. For a moving dipole the source current includes, in addition to the polarization current, a coupling of the polarization to the velocity of the dipole known as the Röntgen current. The magnetic field due to this current is given.
Reduced MEFV messenger RNA expression in patients with familial Mediterranean fever
Authors: Notarnicola Cécile , Didelot Marie‐Noëlle , Koné‐Paut Isabelle , Seguret Fabienne , Demaille Jacques , Touitou Isabelle
Published: October 2002

Objective

Familial Mediterranean fever (FMF) is the most common inherited periodic syndrome. The disease phenotype and the almost exclusive expression of the causative gene, MEFV, in leukocytes suggest that this gene plays an important role in the inflammatory cascade. Since most of the known mutations are conservative, we sought to determine how minor DNA defects can give rise to the dramatic phenotypic features seen in FMF.

Methods

To address whether the molecular basis of the phenotype–genotype correlation could be related to altered MEFV messenger RNA (mRNA) expression, we quantified the relative abundance of MEFV transcripts in peripheral blood leukocytes from patients with FMF, healthy carriers of a single MEFV mutation, and healthy control subjects.

Results

We found significantly lower expression of MEFV mRNA in genetically ascertained FMF patients than in healthy controls (0.7 versus 1.1; P = 0.00001). In healthy carriers, the mRNA levels were intermediate, suggesting a true dose‐response relationship between the number of mutations and the abundance of MEFV transcripts. The difference between healthy controls and healthy carriers was significant (1.1 versus 0.8; P = 0.008), demonstrating that the decrease in mRNA expression is related to a molecular defect independent of FMF symptoms. MEFV mRNA expression was also found to be a function of the type of mutations. The lowest MEFV levels were found in healthy carriers and patients with M694V. Moreover, we observed an inverse correlation with the clinical severity score (r = −0.6, P = 0.04 and r = −0.6, P = 0.004 in patients with 1 and 2 M694V mutations, respectively).

Conclusion

Our results demonstrate that MEFV message levels are related to both the genotype and the phenotype, and suggest that the pathophysiology of FMF relies on a quantitative defect of MEFV mRNA expression.
Ground‐shaking mapping for a scenario earthquake considering effects of geological conditions: a case study for the 1995 Hyogo‐ken Nanbu, Japan earthquake
Authors: Fujimoto Kazuo , Midorikawa Saburoh
Published: October 2002

In order to examine the applicability of ground‐shaking mapping techniques to a near‐field earthquake, a peak ground velocity map of the 1995 Hyogo‐ken Nanbu, Japan earthquake computed from seismic zoning methods that consider the effects of geological conditions is compared with the actual observed intensity map. When computing the ground‐shaking map, the site amplification at each site is calculated in terms of the average shear‐wave velocity of the ground estimated from the corresponding geomorphological conditions. This map shows a relatively good agreement with the observed intensity map. However, the computations provide smaller values for certain disastrous areas of the earthquake, where the effects on ground motion of a deep, irregular underground structure have been reported. The effect of such structures on site response is examined implementing 2D FEM analyses, thereby being also incorporated into the method. Results considering the effect of the irregular underground structure show better agreement with the observed intensity map. Copyright © 2002 John Wiley & Sons, Ltd.
Mutation analysis and mRNA expression of trail‐receptors in human breast cancer
Authors: Seitz Susanne , Wassmuth Peter , Fischer Jörg , Nothnagel Anita , Jandrig Burkhard , Schlag Peter M. , Scherneck Siegfried
Published: October 2002

The chromosome region 8p12‐p22 shows frequent allelic loss in a variety of human malignancies, including breast cancer (BC). The tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL)‐receptors TRAIL‐R1, ‐R2, ‐R3 and ‐R4 are located on 8p21‐p22 and might be candidate tumor suppressor genes in this region. To evaluate the involvement of TRAIL receptors in breast carcinogenesis, we have analyzed the entire coding region of TRAIL‐R2 and the death domain (DD) regions of TRAIL‐R1 and ‐R4 for the detection of somatic mutations in a series of breast tumors, lymph node metastases and BC cell lines. Overall, we detected 1, 11 and 3 alterations in the TRAIL‐R1, ‐R2 and ‐R4 genes, respectively. Although functional studies have not yet been performed, we assume that most of these alterations do not alter the function of TRAIL‐receptors. Additionally, we analyzed individuals from BC families for the detection of TRAIL‐R2 germline mutations. One alteration has been found in the Kozak consensus motif at position ‐4 with respect to the translation initiation AUG [1‐4 (C→A)]. We further studied the mRNA expression of TRAIL and the 4 TRAIL receptors. In BC cell lines, a strongly decreased mRNA expression of TRAIL, TRAIL‐R1, ‐R3 and ‐R4 was found, whereas the expression of TRAIL‐R2 was only slightly reduced. In breast tumors, a 1.2–3.6‐fold reduction of mRNA signals of the 5 genes was observed. No correlation was found between the expression level of TRAIL and the receptor mRNAs and clinicopathologic variables and between the expression of TRAIL‐R2 and TP53 mutation status and loss of heterozygosity (LOH) at 8p21‐p22. Taken together, we cannot exclude the involvement of TRAIL‐receptors in BC. Our mutation studies indicate that DD receptor mutations occur at low frequency and are not the primary cause for the altered mRNA expression of TRAIL and TRAIL‐receptors in BC. © 2002 Wiley‐Liss, Inc.
Fiber coating with surfactant solutions
Authors: Shen Amy Q. , Gleason Blake , McKinley Gareth H. , Stone Howard A.
Published: October 2002

When a fiber is withdrawn at low speeds from a pure fluid, the variation in the thickness of the entrained film with imposed fiber velocity is well-predicted by the Landau–Levich–Derjaguin (LLD) equation. However, surfactant additives are known to alter this response. We study the film thickening properties of the protein BSA (bovine serum albumin), the nonionic surfactant Triton X-100, and the anionic surfactant SDS (sodium dodecyl sulfate). For each of these additives, the film thickening factor α (the ratio of the measured thickness to the LLD prediction) for a fixed fiber radius varies as a function of the ratio of the surfactant concentration c to the critical micelle concentration (CMC). In the case of BSA, which does not form micelles, the reference value is the concentration at which multilayers form. As a result of Marangoni effects, α reaches a maximum as c approaches the CMC from below. However, when the surfactant concentration c exceeds the CMC, the behavior of α varies as a consequence of the dynamic surface properties, owing for example to different sorption kinetics of these additives, or possibly surface or bulk rheological effects. For SDS, α begins to decrease when c exceeds the CMC and causes the surface to become partially or completely remobilized, which is consistent with the experimental and theoretical results published for studies of slug flows of bubbles and surfactant solutions in a capillary tube and the rise of bubbles in surfactant solutions. However, when the SDS or Triton X-100 surfactant concentration is well above the CMC, we observe that the film thickening parameter α increases once again. In the case of SDS we observe a second maximum in the film thickening factor. For all the experiments, transport of monomers to the interface is limited by diffusion and the second maximum in the film thickening factor may be explained as a result of a nonmonotonic change in the stability characteristics of suspended SDS micelles and corresponding changes in the rheology of the solution.
PARAMETRIC POLYMATROID OPTIMIZATION AND ITS GEOMETRIC APPLICATIONS
Authors: KATOH NAOKI , TAMAKI HISAO , TOKUYAMA TAKESHI
Published: October 2002

We give an optimal bound on the number of transitions of the minimum weight base of an integer valued parametric polymatroid. This generalizes and unifies Tamal Dey's O(k1/3 n) upper bound on the number of k-sets (and the complexity of the k-level of a straight-line arrangement), David Eppstein's lower bound on the number of transitions of the minimum weight base of a parametric matroid, and also the Θ(kn) bound on the complexity of the at-most-k level (the union of i-levels for i = 1,2,…,k) of a straight-line arrangement. As applications, we improve Welzl's upper bound on the sum of the complexities of multiple levels, and apply this bound to the number of different equal-sized-bucketings of a planar point set with parallel partition lines. We also consider an application to a special parametric transportation problem.
First carbonyl metallo immunoassay in the environmental area: application to the herbicide chlortoluron
Authors: Vessières Anne , Fischer‐Durand Nathalie , Le Bideau Franck , Janvier Pierre , Heldt Jan‐Martin , Ben Rejeb Samy , Jaouen Gérard
Published: October 2002

We report a new, non‐isotopic, immunoassay (CMIA) for chlortoluron, a pesticide of the phenylurea family. The novel feature of this assay is the use of metal carbonyl complexes as tracers and Fourier‐transform infrared (FT‐IR) spectroscopy as the detection method. We describe the synthesis of three tracers, derivatives of chlortoluron with an attached cyclopentadienyl manganese tricarbonyl moiety. Quantitative analysis of these tracers, by FT‐IR spectroscopy was performed by simple measurement of the absorbance peak at 2033 cm−1, characteristic of the νCO of the metal‐carbonyl unit. Immunoassays were carried out using the IgG fraction of rabbit antiserum. Standard curves obtained by CMIA for the three tracers showed the feasibility of this technique for chlortoluron assay. However, the IC50 and IC90 values obtained with the three tracers varied widely, with the long‐chain tracer 12 giving the most sensitive assay for chlortoluron, with an IC50 value of 50 pmol (21 µg l−1) and an IC90 of 6.5 pmol (2.7 µg l−1). Copyright © 2002 John Wiley & Sons, Ltd.
Studies on mixed trialkyltin derivatives: preparation and biological activity of (2‐phenyl‐2‐methylpropyl)dicyclohexyltinO,O‐dialkyldithiophosphates
Authors: Yuan Fei , Huang Yanqin , Xie Qinglan
Published: October 2002

Fifteen compounds based on (2‐phenyl‐2‐methylpropyl)dicyclohexyltinO,O‐dialkyldithiophosphates have been synthesized by the reaction of (2‐phenyl‐2‐methylpropyl)dicyclohexyltin chloride with potassiumO,O‐dialkyldithiophosphoric acids. Their structure and composition were characterized by1H NMR, IR spectroscopy, elemental analysis and X‐ray diffraction. The structure of PhMe2CCH2Sn(Cy2)S2P(OC6H4tBu‐4)2has been shown to consist of a four‐coordinate tin atom in a slightly distorted tetrahedral geometry. Biological activities were tested for some of the compounds. The results show that these kinds of compound have acaricidal activity. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and polycondensation of some new organotellurium compounds containing hydroxymethyl groups
Authors: Al‐Rubaie Ali Z. , Al‐Jadaan Shaker A. S.
Published: October 2002

A new series of organotellurium compounds [i.e. 2‐HOCH2C6H4TeBr3 (1), (2‐HOCH2C6H4)2TeBr2 (2), (2‐HOCH2C6H4)2Te (3), (2‐HOCH2C6H4Te)2 (4), 4‐HOCH2C6H4TeBr3 (5), (4‐HOCH2C6H4)2TeBr2 (6), (4‐HOCH2C6H4)2Te (7), and (4‐HOCH2C6H4Te)2 (8)] were prepared by reacting hydroxymethylphenylmercury chlorides with tellurium tetrabromide in dry dioxane. Bis(2‐hydroxymethylphenyl) telluride (3), bis(2‐hydroxymethylphenyl) ditelluride (4) and bis(4‐hydroxymethylphenyl) telluride (7) were polymerized by a solution polycondensation technique with toluene diisocyanate and terephthaloyl chloride, leading to new organic tellurium polyurethanes and polyesters. All the new compounds were characterized by elemental analysis and spectroscopic data. Copyright © 2002 John Wiley & Sons, Ltd.
Melt rheology and morphology of LLDPE/EVA blends: Effect of blend ratio, compatibilization, and dynamic crosslinking
Authors: Moly K. A. , Oommen Z. , Bhagawan S. S. , Groeninckx G. , Thomas S.
Published: October 2002

The melt rheological properties of linear low‐density polyethylene (LLDPE)/ethylene vinyl acetate (EVA) blends were investigated with special reference to the effect of blend ratio, temperature, shear rate, compatibilization, and dynamic vulcanization. The melt viscosity of the blends determined with a capillary rheometer is found to decrease with an increase of shear rate, which is an indication of pseudoplastic behavior. The viscosity of the blend was found to be a nonadditive function of the viscosities of the component polymers. A negative deviation was observed because of the interlayer slip between the polar EVA and the nonpolar LLDPE phases. The melt viscosity of these blends decreases with the increased concentration of EVA. The morphology of the extrudate of the blends at different shear rates and blend ratios was studied and the size and distribution of the domains were examined by scanning electron microscopy. The morphology was found to depend on shear rate and blend ratio. Compatibilization of the blends with phenolic‐ and maleic‐modified LLDPE increased the melt viscosity at lower wt % of compatibilizer and then leveled off. Dynamic vulcanization is found to increase the melt viscosity at a lower concentration of DCP. The effect of temperature on melt viscosity of the blends was also studied. Finally, attempts were made to correlate the experimental data on melt viscosity and cocontinuity region with different theoretical models. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3210–3225, 2002
Method for quantitative evaluation of kinetic constants in olefin polymerizations. II. Kinetic study of a high‐activity Ziegler–Natta catalyst used for bulk propylene polymerizations
Authors: Matos Válter , Mattos Neto Antônio G. , Nele Márcio , Pinto José Carlos
Published: October 2002

A method for quantitative evaluation of kinetic constants in Ziegler–Natta and metallocene olefin polymerizations presented previously (Matos, V.; Mattos Neto, A. G.; Pinto, J. C. J Appl Polym Sci 2001, 79, 2076) is adapted to allow the estimation of kinetic constants for bulk propylene polymerizations by using a conventional fourth‐generation high‐activity Ziegler–Natta catalyst (HAC). In this particular case, reaction rate profiles are not available, so that estimation of kinetic data must rely on average polymer yields. The method comprises some fundamental steps, including the initial design of a statistical experimental plan, the execution of the designed experiments, the development of simple mathematical models to describe the polymerization, and the estimation of kinetic parameters from available yields, gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) data. It is shown that the proposed method allows the successful interpretation of experimental olefin polymerization data and the quantitative evaluation of kinetic parameters, which can be inserted into a process simulator to provide an accurate picture of actual industrial plant behavior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3226–3245, 2002
Synthesis and characterization of BTDA‐based dimethacrylate dental adhesive monomer and its interaction with Ca2+ ions
Authors: Atai M. , Nekoomanesh M. , Hashemi S. A. , Yeganeh H.
Published: October 2002

A BTDA‐based dimethacrylate monomer was synthesized via reaction of 3, 3′, 4, 4′‐Benzophenone tetracarboxylic dianhydride (BTDA) and 2‐Hydroxyethyl methacrylate (HEMA).The reactions were followed using FTIR spectroscopy and the product was characterized and confirmed using FTIR, 1H‐NMR, and Elemental Analysis. The effects of temperature and pyridine as catalyst were investigated. The water contact angle on the surface of cured BTDMA and Bis‐GMA‐based resins were also measured and compared. FTIR studies showed an interaction between carboxylic acid groups of BTDMA and Ca2+ ions of CaO. The interaction of the resin with hydroxyapatite and tooth ash was also investigated. The interaction was also studied using thermogravimetric analysis (TGA). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3246‐3249, 2002
Relationship between interfacial tension and dispersed‐phase particle size in polymer blends. I. PP/EPDM
Authors: Shariatpanahi H. , Nazokdast H. , Dabir B. , Sadaghiani K. , Hemmati M.
Published: October 2002

Simple blends with different viscosity ratios of the components as well as compatibilized blends varying both in type and content of compatibilizers were used to study the relation between interfacial tension and dispersed‐phase particle size for PP/EPDM (80/20 wt %) blends in this work. Four compatibilizing systems, poly(ethylene‐co‐methacrylic acid) ionomers (EMA–I), dicumyl peroxide (DCP), DCP combined with EMA–I, and DCP in combination with trimethylol propane triacrylate (TMPTMA), were used. For blends prepared in an internal mixer, a power law relation was found between capillary number and torque ratio of the blends' components. This relation was used to estimate the interfacial tension for the compatibilized blends. The relation between steady‐state torque of the blends as a measure of viscosity and the estimated values of interfacial tension were also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3148–3159, 2002
Elongational flow studies on the phase separation of hydroxypropylcellulose solution
Authors: Fujii Syuji , Sasaki Naoki , Nakata Mitsuo
Published: October 2002

The phase separation of hydroxypropylcellulose (HPC) in a mixed solvent of glycerol and water was investigated by an elongational flow birefringence method. In the one‐phase region, the elongational flow birefringence had the characteristics of a typical coil‐stretch transition‐like pattern with a critical elongational strain rate \documentclass{article}\pagestyle{empty} \begin{document}$\dot \varepsilon_c.$\end{document} \documentclass{article}\pagestyle{empty} \begin{document}$\dot \varepsilon_c.$\end{document} increased monotonously with temperature, but in the vicinity of the phase‐separation point,
\documentclass{article}\pagestyle{empty} \begin{document}$\dot \varepsilon_c.$\end{document} began to decrease even in the one‐phase region. In the two‐phase region, the flow‐induced birefringence pattern contained both a rigid rod‐like response and the coil‐stretch transition‐like response of a flexible polymer. The appearance of the rod‐like birefringence pattern indicates the association of HPC chains to form a precursor of the liquid‐crystalline phase formation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2984–2991, 2002
Rice‐husk‐ash‐based silica as a filler for embedding composites in electronic devices
Authors: Suwanprateeb J. , Hatthapanit K.
Published: October 2002

We carried out a feasibility study of the use of black rice husk ash (RHA) as a filler in epoxy resin for embedding material in electrical and electronic applications. We made a comparison by mixing RHA and two commercial fillers, fused and crystalline silica, with epoxy resin at weight fractions ranging from 20–60%. RHA‐filled epoxy resin had higher mixing viscosity, coefficient of thermal expansion, and water absorption percentage than commercial‐silica‐filled epoxy composite. However, the impact strength of all composites was comparable, but the tensile strength and elongation at break of silica‐filled epoxy were slightly superior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3013–3020, 2002
Microgels as new support materials for heterogeneous cocatalysts in ethylene polymerization reactions
Authors: Helldörfer Markus , Alt Helmut G. , Ebenhoch Jochen
Published: October 2002

Microgels are monodisperse poly(organosiloxane) microparticles that can be functionalized at their surface. These materials were tested as supports for heterogeneous cocatalysts of the methylaluminoxane type and were used for the polymerizations of olefins with transition‐metal catalysts. The cocatalysts were synthesized directly on the surfaces of the microgel particles by the partial hydrolysis of trimethylaluminum and were then used for the activation of homogeneous catalyst precursors. Complexes of various chemical natures were successfully activated and optimized through variations in the Al/H2O ratio used for the synthesis. Metallocene dichloride complexes and coordination compounds of iron and nickel were tested as catalysts for ethylene polymerization, and the results were compared with the results for the homogeneous systems and heterogeneous systems supported on silica gel (SiO2). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3021–3029, 2002
Microdispersion of polyphenylene ether in polyphenylene sulfide/polyphenylene ether alloy compatibilized by styrene‐co‐glycidyl methacrylate
Authors: Kubo Kimihiro , Masamoto Junzo
Published: October 2002

The polyphenylene sulfide/polyphenylene ether (PPS/PPE) alloy is desired for use as an engineering plastic. In this case, microdispersion of PPE in the PPS matrix is preferable. We have developed a new method for the preparation of a PPS/PPE alloy that has microdispersed PPE in the PPS matrix. The reactive processing of PPS with PPE gave a PPS/PPE alloy with a microdispersed PPE in the PPS matrix, using styrene‐co‐glycidyl methacrylate copolymer (SG) as a compatibilizer. Although the general properties of the PPS/PPE alloy did not depend on the PPE particle size, tensile strength at the weld part is found to be strongly dependent on PPE particle size. Only the finely dispersed PPE system gave tensile strength at the weld part comparable that of PPS. The PPS/PPE alloy shows superior property to PPS at elevated temperature and, moreover, attains the an advantage of precise molding. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3030–3034, 2002
Electrochemical degradation of polyfuran in wet acetonitrile and aqueous solutions
Authors: Wan Xiao‐Bo , Li Liang , He Jin‐Bo , Zhou Dong‐Shan , Xue Gi , Wang Tian‐Wei
Published: October 2002

The degradation of polyfuran in a wet acetonitrile solution and in an aqueous solution has been investigated with a cyclic voltammetry technique, along with Fourier transform infrared and Fourier transform Raman spectroscopy techniques. Infrared spectroscopy shows that the main defects that exist in polyfuran after cycling in dried acetonitrile are mainly saturated CH structures, whereas those after cycling in an aqueous solution are mainly carbonyl groups in the polymer chain. This may be because polyfuran can undergo degradation through a crosslinking mechanism in a dried acetonitrile solution, whereas in an aqueous solution, it undergoes degradation through a nucleophilic attack mechanism. Raman spectroscopy shows that not all the furan rings are involved in the degradation process, although the electrochemical activity of polyfuran is totally lost in an aqueous solution after only one cycle. The sites that are sensitive to the degradation process may be the electrochemically active sites, that is, the positively charged sites in polyfuran chains. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3160–3165, 2002
Headspace solid‐phase microextraction with gas chromatography/mass spectrometry reveals a correlation between the degradation product pattern and changes in the mechanical properties during the thermooxidation of in‐plant recycled polyamide 6,6
Authors: Gröning Mikael , Hakkarainen Minna
Published: October 2002

The increased susceptibility of in‐plant recycled polyamide 6,6 toward thermooxidation was shown by headspace solid‐phase microextraction with gas chromatography/mass spectrometry (HS‐SPME/GC‐MS), tensile testing, differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). A correlation between the deterioration in mechanical properties and the formation of degradation products due to thermooxidation was found, and the most prominent decrease in mechanical properties coincided with the largest increase in the abundance of degradation products. The recycled materials had a shorter induction period toward oxidation, and their mechanical properties deteriorated faster than the mechanical properties of virgin material. The same trend was observed with HS‐SPME/GC‐MS because degradation products were found for recycled materials after oxidation times shorter than those for virgin material. Furthermore, larger amounts of degradation products were formed in the recycled materials. The high sensitivity of HS‐SPME/GC‐MS as an analytical tool was demonstrated because it was able to detect changes caused by oxidation considerably earlier than the other methods. Unlike DSC and FTIR, it could also show differences between samples recycled for different times. Four groups of degradation products—cyclic imides, pyridines, chain fragments, and cyclopentanones—were identified in thermooxidized polyamide 6,6. After 1200 h of thermooxidation, 1‐pentyl‐2,5‐pyrrolidinedione was the most abundant degradation product. Approximately four times more 1‐pentyl‐2,5‐pyrrolidinedione was formed in polyamide recycled three times than in virgin polyamide. Pyridines and chain fragments behaved toward oxidation and repeated processing like cyclic imides; that is, their amounts increased during oxidation, and larger amounts were formed in recycled materials than in virgin material. The cyclopentanone derivatives were present already in unaged material, and their amounts decreased during oxidation. Cyclopentanones were not formed because of the thermooxidation of polyamide 6,6. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3396–3407, 2002
Antiwear and lubrication properties of polyurethane/polytetrafluoroethylene‐bonded coating
Authors: Tian J. , Huang Y. L.
Published: October 2002

Polytetrafluoroethylene (PTFE) particles were irradiated with 60Co γ‐ray to improve their dispersing capacity in polyurethane (PU), which was used as a binder of a PTFE‐based bonded solid lubricating coating. The PU/PTFE‐bonded solid lubricating coating was prepared on a steel block by spraying and curing at room ambient, and the tribological properties of the PU/PTFE coatings were evaluated on a ring‐on‐block tester at a speed of 1.25–2.5 m/s and a load of 314–785 N. The wear life of bonded coatings on PTFE volume concentrations, curing humidities and times, coating thickness, and sliding conditions was also investigated. It was found that a 60‐μm thickness coating, which has a 40% PTFE volume concentration, cured at 75% relative humidity for 4 days, has a longer wear life of 844 m/μm at 314 N and 1.25 m/s. The PTFE/PU coating was wear‐resistant when the load × speed value was less than 687 Nm/s−1; at same time, the wear life for a thinner coating is sensitive to sliding condition variations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3454–3459, 2002
Lesbian and gay identity: European perspectives
Authors: Markowe Laura A.
Published: October 2002

Distinctive European social psychological perspectives on lesbian and gay identity reflect an emphasis on thoroughly social understandings and on multiple identities, often examined using qualitative research methods. Potential areas for future study include the relationship between lesbian, gay and bisexual identities and emerging European identity/identities. Copyright © 2002 John Wiley & Sons, Ltd.
Radical prostatectomy or external beam radiotherapy
Authors: Roach Mack
Published: October 2002

D'Amico et al. hypothesized that “low‐risk” and low biopsy tumor volume “intermediate‐risk” patients who are treated with RP fare significantly better than patients treated with conventional‐dose RT. However, patient selection and the choice of end points as well as the use of low dose radiation leaves this issue unresolved.

See also pages 211–4 and 281–6.
Impact of aging on the development of hepatocellular carcinoma in patients with posttransfusion chronic hepatitis C
Authors: Hamada Hisayuki , Yatsuhashi Hiroshi , Yano Koji , Daikoku Manabu , Arisawa Kokichi , Inoue Osami , Koga Michiaki , Nakata Keisuke , Eguchi Katsumi , Yano Michitami
Published: October 2002

BACKGROUND

Hepatitis C virus (HCV) infection is a heterogeneous disease, the natural history of which remains controversial. There is solid evidence that chronic HCV infection is responsible for the occurrence of hepatocellular carcinoma (HCC). The aim of the current cohort study was to determine the rate of the development of HCC from the time of primary HCV infection and to assess the risk factors for the development of HCC in chronic posttransfusion hepatitis C patients.

METHODS

Four hundred sixty‐nine patients with clinically compensated HCV, who had undergone a single blood transfusion comprised the current study cohort. Patients with other risk factors for chronic liver disease were excluded. All patients were referred to the liver center at the National Nagasaki Medical Center between December 1980 and December 1998 and were followed prospectively until the end of the analysis (June 2000).

RESULTS

Follow‐up data were obtained for 445 patients. The mean duration from HCV infection to the end of the observation was 28 years. Fifty‐two patients (11.1%) progressed to HCC. The mean duration from the time of blood transfusion to the diagnosis of HCC was 31 years. Multivariate Cox regression analyses revealed age, fibrosis, duration from HCV infection to study entry, and alcohol consumption to be the independent factors affecting the development of HCC. The risk of developing HCC in patients age ≥ 56 years was increased 7.8‐fold compared with that in patients age < 56 years. The mean age of patients at the time of HCC diagnosis was 65 years (range, 58–79 years).

CONCLUSIONS

At the time of diagnosis, 92% of the 52 HCC patients were age > 60 years and 38 of the HCC patients (73%) were in their 60s. There was a significantly negative correlation between the duration from HCV infection to the development of HCC and the age of the patient at the time of infection (correlation coefficient = 0.702; P < 0.0001; Y = 61.1–0.82X), indicating that the age of patients, rather than the duration of HCV infection, is more significant for HCC development in patients with posttransfusion HCV. Moreover, these data may contribute to the design of an optimal follow‐up schedule for patients with posttransfusion HCV. Cancer 2002;95:331–9. © 2002 American Cancer Society.

DOI 10.1002/cncr.10662
Treating cancer with PEG Intron
Authors: Bukowski Ronald M. , Tendler Craig , Cutler David , Rose Esther , Laughlin Mark M. , Statkevich Paul
Published: October 2002

BACKGROUND

PEG Intron (pegylated interferon‐alpha‐2b [IFN‐α‐2b]; Schering‐Plough, Kenilworth, NJ) has demonstrated delayed clearance and increased area under the curve compared with native IFN‐α‐2b. Studies in patients with chronic hepatitis C infection and malignancies have demonstrated both biologic and clinical activity of PEG Intron and have provided empiric data to compare the pharmacokinetics (PK) and pharmacodynamics of PEG Intron and IFN‐α‐2b.

METHODS

The authors conducted a review of the available data comparing the PK and pharmacodynamic effects of PEG Intron and IFN‐α‐2b. Safety and efficacy data from Phase I/II studies of PEG Intron in patients with chronic myelogenous leukemia (CML) and solid tumors were also reviewed.

RESULTS

Data from patients with chronic hepatitis C infection suggest that exposure to IFN at a PEG Intron dose of 0.25 μg/kg per week is similar to that observed after administration of IFN‐α‐2b at a dose of 3 million International Units, three times per week. PEG Intron at doses up to 6 μg/kg per week was well tolerated and demonstrated clinical activity in patients with CML and solid tumors, including metastatic melanoma and renal cell carcinoma.

CONCLUSIONS

Dose intensification can be achieved safely in patients with CML and solid tumors using PEG Intron, which could improve efficacy. These results provide useful dosing guidelines to clinicians investigating the antitumor activity of PEG Intron in patients with malignancies. More data are needed to determine the optimal dose in various oncologic indications. However, these results provide a sound rationale for further investigation of PEG Intron. Cancer 2002;95:389–96. © 2002 American Cancer Society.

DOI 10.1002/cncr.10663
Initial decline in hemoglobin during neoadjuvant hormonal therapy predicts for early prostate specific antigen failure following radiation and hormonal therapy for patients with intermediate and high‐risk prostate cancer
Authors: D'Amico Anthony V. , Saegaert Tara , Chen Ming‐Hui , Renshaw Andrew A. , George Daniel , Oh William , Kantoff Philip W.
Published: October 2002

BACKGROUND

Declines in serum hemoglobin (Hgb) levels occur from the use of androgen suppression therapy (AST) in the treatment of prostate cancer patients. We studied whether time to prostate specific antigen (PSA) failure following external beam radiation therapy (RT) and AST could be predicted by the rate of decline in the Hgb level following the administration of neoadjuvant AST or by the Hgb level at presentation or at the start of RT.

METHODS

The study cohort comprised 110 intermediate or high‐risk prostate cancer patients who were managed using three‐dimensional conformal RT (70 Gy) and 6 months of AST (2 months neoadjuvant, concurrent, and adjuvant). A Cox regression multivariable analysis was performed to evaluate the ability of the rate of decline of the Hgb from baseline to the start of RT, baseline PSA level, Gleason score, percent positive biopsies, and T‐category to predict time to PSA failure.

RESULTS

A decline in the Hgb level of 1 g/dL or more during the first month of AST was the only significant predictor of time to PSA failure (P= 0.02) on multivariable analysis. The relative risk of PSA failure (95% confidence interval) for patients with a decline in Hgb level during the first month (≥ 1 g/dL vs. < 1 g/dL) was 6.3 (2.4, 8.3) and the 3‐year estimate of PSA outcome was 66% versus 82% (P= 0.04), respectively. There were no imbalances in the pretreatment prognostic factors or length of follow‐up in each of these groups.

CONCLUSION

A decline of 1 g/dL or more in Hgb level during the first month of neoadjuvant AST was a predictor of early PSA failure following RT and AST in intermediate and high‐risk prostate cancer patients. Cancer 2002;95:275–80. © 2002 American Cancer Society.

DOI 10.1002/cncr.10673
Proteins of the PDI family: Unpredicted non‐ER locations and functions
Authors: Turano Carlo , Coppari Sabina , Altieri Fabio , Ferraro Anna
Published: October 2002

Protein disulfide isomerases (PDIs) constitute a family of structurally related enzymes which catalyze disulfide bonds formation, reduction, or isomerization of newly synthesized proteins in the lumen of the endoplasmic reticulum (ER). They act also as chaperones, and are, therefore, part of a quality‐control system for the correct folding of the proteins in the same subcellular compartment. While their functions in the ER have been thoroughly studied, much less is known about their roles in non‐ER locations, where, however, they have been shown to be involved in important biological processes. At least three proteins of this family from higher vertebrates have been found in unusual locations (i.e., the cell surface, the extracellular space, the cytosol, and the nucleus), reached through an export mechanism which has not yet been understood. In some cases their function in the non‐ER location is clearly related to their redox properties, but in most cases their mechanism of action has still to be disclosed, although their propensity to associate with other proteins or even with DNA might be the main factor responsible for their activities. © 2002 Wiley‐Liss, Inc.
Structural characterization of acetylpyridinium–ethyl pyruvate adducts by electrospray ionization mass spectrometry
Authors: Bartók Mihály , Bartók Tibor , Szöllősi György , Felföldi Károly
Published: October 2002

The reactions of ethyl pyruvate with acetic anhydride and pyridine were studied by electrospray ionization mass spectrometry (ESI‐MS). Ethyl 2‐acetoxy‐2‐pyridiniumpropionate (1) (m/z 238) resulting from the reaction of the acetylpyridinium cation with ethyl pyruvate, and the adduct of ethyl 2‐acetoxyacrylate with a pyridinium cation (2), bound together by non‐covalent interactions (m/z 238), were identified by ESI‐MS for the first time. Structures 1 and 2 cannot be distinguished, probably because one may be converted into the other and vice versa. Copyright © 2002 John Wiley & Sons, Ltd.