bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the morphology of the hydrophobically‐modified polyelectrolyte in aqueous solution by AFM measurements
Authors: Ye Lin , Huang Ronghua , Hoffmann Heinz , Wang Chun 
Published: May 2004

AbstractThis work focuses on the AFM study of the aggregation morphology and association mechanism of the hydrophobically‐association water‐soluble polymer P (AM‐AA‐BPAM) in aqueous solution. It shows that the P (AM‐AA‐BPAM) molecule chain, which has hydrophobic and hydrophilic ionic groups, forms the “spherical” aggregations as micelles below 0.2 g · dL−1, and then connect each other to form the string‐like aggregations, which produce large viscosity for the polymer solution. It is also coincident with the FCS, DLS, and viscosity study result. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1175–1178, 2004
Drug complexation and physicochemical properties of vinylpyrrolidone‐N,N′‐dimethylacrylamide copolymers
Authors: de Queiroz Alvaro A. A. , França Écio J. , Abraham Gustavo A. , Roman Julio San 
Published: May 2004

AbstractSolid dispersions of the nonsteriodal antiinflammatory drug (NSAID) 2′,4′‐difluoro‐4‐hydroxy‐(1,1′‐biphenyl)‐3‐carboxylic acid (DIF) with the water‐soluble random copolymer poly(N‐vinyl‐2‐pyrrolidone‐co‐N,N′‐dimethylacrylamide) (VP‐co‐DMAm) were prepared by the solvent method (coevaporates) and melting DIF/VP‐co‐DMAm (cofused) physical mixtures. Differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) were used to elucidate the possible interaction between the NSAID drug and VP‐co‐DMAm in cofused and coevaporated polymer–drug solid dispersions. The XRD and FTIR studies suggest the presence of physical interactions with formation of a charge transfer complex between DIF and the VP‐co‐DMAm copolymers as a consequence of the coevaporation or cofusion processes. In solution, dynamic and equilibrium solubility studies were determined to elucidate the mechanism of interaction between DIF and VP‐co‐DMAm copolymers. Thermodynamics data about the DIF: VP‐co‐DMAm dissolution process indicate that the coevaporated systems are more stable that the cofused systems. The dissolution of the cofused and coevaporated systems was diffusion controlled and the dissolution kinetics followed the Noyes–Whitney and the Levich equations. Molecular simulations using semiempirical quantum chemical calculations reinforce the experimental results, suggesting that the improvement in the DIF solubility could be attributed to the charge transfer complex formation between the drug and VP‐co‐DMAm copolymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1337–1347, 2004
Influence of LiClO4 on the thermal, mechanical, and morphological properties of P(DMS‐co‐EO)/ P(EPI‐co‐EO) blends
Authors: Fonseca C. P. , Guedes C. G. F. , Rosa D. S. , Neves S. 
Published: May 2004

AbstractThe UV‐vis absorption, thermal analysis, ionic conductivity, mechanical properties, and morphology of a blend of poly(dimethylsiloxane‐co‐ethylene oxide) [P(DMS‐co‐EO)] and poly(epichlorohydrin‐co‐ethylene oxide) [P(EPI‐co‐EO)] (P(DMS‐co‐EO)/P(EPI‐co‐EO) ratio of 15/85 wt %) with different concentrations of LiClO4 were studied. The maximum ionic conductivity (σ = 1.2 × 10−4 S cm−1) for the blend was obtained in the presence of 6% wt LiClO4. The crystalline phase of the blend disappeared with increasing salt concentration, whereas the glass transition temperature (Tg) progressively increased. UV‐vis absorption spectra for the blends with LiClO4 showed a transparent polymer electrolyte in the visible region. The addition of lithium salt decreased the tensile strength and elongation at break and increased Young's modulus of the blends. Scanning electron microscopy showed separation of the phases between P(DMS‐co‐EO) and P(EPI‐co‐EO), and the presence of LiClO4 made the blends more susceptible to cracking. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1230–1235, 2004
Dynamic mechanical thermal analysis of thermally stable and thermally reactive network polymers
Authors: Cook W. D. , Scott T. F. , Quay‐Thevenon S. , Forsythe J. S. 
Published: May 2004

AbstractThe temperature and frequency dependence of the dynamic mechanical properties in the glass transition was studied for a series of partially cured thermally reactive networks (low temperature cured epoxy and a dimethacrylate photocured with a conventional initiator) and more thermally stable networks (high temperature cured epoxy and two dimethacrylates photocured with a photoiniter1). The viscoelastic behavior in the transition region of the former networks changed during the experiment due to additional cure, whereas the thermally stable networks enabled the study of the effect of conversion on the transition region. The glass transition temperatures showed 1 : 1 relationships with the isothermal curing temperatures and were correlated with the degree of conversion. The breadth of the glass transition, as determined from the real and loss moduli, tan δ, and the loss compliance in the temperature and frequency domains, was found to be greater for the dimethacrylate networks than for the epoxy networks. The breadth of the transition for the dimethacrylates was not significantly dependent on the degree of cure. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1348–1359, 2004
A kinetic investigation of the in situ polymerization of methyl methacrylate under supercritical fluid CO2 conditions using high‐pressure DSC
Authors: Lu Shiying , Zhang Zhiyi , Nawaby A. Victoria , Day Michael 
Published: May 2004

AbstractThe polymerization kinetics of methyl methacrylate (MMA) under supercritical fluid CO2 was studied by using high‐pressure DSC. The results indicate that CO2 can significantly reduce the cage effect and improve the chain propagation reactions, with the observed solvent‐like effects being enhanced by increased CO2 pressures. The polymerization of MMA under isothermal conditions and 56 atm of CO2 was characterized by a first‐order kinetic rate expression over the conversion range 20–80%. The apparent activation energy for the reaction was found to be 51.6 kJ/mol, which is less than the value reported under ambient conditions (68.2 kJ/mol). The polymerization kinetics were also evaluated under nonisothermal conditions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1236–1239, 2004
Bithiazole‐containing polymeric complex and PVA composite film: Preparation and magnetic properties
Authors: Lin Caiping , Sun Weilin , Jiang Liming , Wang Liqun , Shen Zhiquan 
Published: May 2004

AbstractTwo novel bithiazole‐containing polyamides, DClAI and DTTPA, and their complexes were synthesized by condensation and complexation. Novel homogeneous composite films were prepared by in situ blending these complexes with polyvinyl alcohol. These polymeric complexes and composite films were characterized by FTIR. The magnetic properties of the complex and its related composite film were measured using a physical property measurement system. It was found that the properties of films are similar to those of their related polymeric complexes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1264–1270, 2004
In vitro laser ablation of laboratory developed biofilms using an Nd:YAG laser of 532 nm wavelength
Authors: Nandakumar Kanavillil , Obika Hideki , Utsumi Akihiro , Ooie Toshihiko , Yano Tetsuo 
Published: May 2004

AbstractWe studied the laser ablation of laboratory‐developed biofilm on titanium and glass surfaces. Specifically, Pseudoalteromonas carrageenovora, a marine biofilm forming bacterium was used to generate laboratory biofilm. Two fluences, 0.05 and 0.1 J/cm2 and three durations of irradiation, 30 s, 5 min, and 10 min were tested using an Nd;YAG laser of 532 nm wavelength (in the green light area). Nonirradiated coupons with biofilm served as control. The biofilm removal efficiency increased with the increase in laser fluence and duration of irradiation. The maximum biofilm area cover on control coupons of glass and titanium was 62.5 and 76.0%, respectively. Upon irradiation with fluence 0.1 J/cm2 for the very short duration of 30 s, this reduced to 5.6 and 12.4% and at 10 min to 2.17 and 0.7% on glass and titanium coupons, respectively, while the controls did not show any reductions (62.5 and 76.0% respectively, for glass and titanium coupons). The biofilm TRC (Total Resuscitated Cells) reduction during this period was even more prominent than the area cover, indicating that the remaining biofilm portions on coupons after irradiation were largely composed of dead bacterial cells. The TRC in the irradiation chamber medium for short durations of irradiation showed a significant increase, indicating that the laser irradiation removed live bacteria from the biofilm. The re‐growth of the resuscitated cells showed they could grow like the control cells but with a significant lag. The laser's efficiency in the removal of biofilm was better seen on titanium coupons than on glass. Our results showed that a low‐ power pulsed laser irradiation could be used to remove biofilm formed on hard surfaces. © 2004 Wiley Periodicals, Inc.
Direct Synthesis of Tricarbonyl(cyclopentadienyl)rhenium and Tricarbonyl(cyclopentadienyl)technetium Units from Ferrocenyl Moieties − Preparation of 17α‐Ethynylestradiol Derivatives Bearing a Tricarbonyl(cyclopentadienyl)technetium Group
Authors: Masi Stéphane , Top Siden , Boubekeur Leila , Jaouen Gérard , Mundwiler Stefan , Spingler Bernhard , Alberto Roger 
Published: May 2004

AbstractThe preparation of new tricarbonyl(cyclopentadienyl)rhenium and tricarbonyl(cyclopentadienyl)technetium derivatives is described. The approach used was applied to a cold target model, 17α‐ethynylestradiol substituted at the 17α position by a ketotricarbonyl(cyclopentadienyl)rhenium group. The novel organometallic reaction applied here, when extended to potential radiopharmaceuticals, consists of a cyclopentadienyl‐ligand transfer between ketoferrocenes and fac‐[99mTc(H2O)3(CO)3]+ in a water/DMSO 1:1 mixture. This reaction lead to the synthesis of a new estradiol derivative, labeled with 99mTc. The synthesis of another product was performed by using [99TcCl3(CO)3]2− as the Tc precursor and its X‐ray crystal structure was determined. In each case high yields were obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Lanthanide(II) and ‐(III) Porphyrinogens − Rational Synthesis and Derivatisation of Mononuclear, Alkali‐Metal‐Free Lanthanide(II) and ‐(III) meso‐Octaalkylporphyrinogen Complexes
Authors: Wang Jun , Dick Andrew K. J. , Gardiner Michael G. , Yates Brian F. , Peacock Evan J. , Skelton Brian W. , White Allan H. 
Published: May 2004

AbstractModifying the porphyrinogen framework in lanthanide porphyrinogen complexes by trans‐N,N′‐dimethylation results in SmII and SmIII derivatives that are remarkably simple in structure and formulation, and are amenable to highly controllable further reaction chemistry. The SmII bis(tetrahydrofuran) adduct, SmIII chloride and bis(trimethylsilyl)amide complexes have been synthesised and characterised by elemental analysis, 1H and 13C NMR spectroscopy and X‐ray crystal structure determinations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Antioxidant activity of phenolic compounds in sunflower oil‐in‐water emulsions containing sodium caseinate and lactose
Authors: Velasco Joaquín , Dobarganes M. Carmen , Márquez‐Ruiz Gloria 
Published: May 2004

AbstractThe aim of this work was to study the evolution of oxidation and the efficiency of phenolic antioxidants in sunflower oil‐in‐water emulsions containing sodium caseinate and lactose (Cas‐Lac) or stabilized by Tween‐20 (T‐20). Two groups of phenolic antioxidants which are structurally similar were tested, i.e. (1) α‐tocopherol and its water‐soluble analogue, Trolox; and (2) gallic acid and its ester derivatives propyl gallate and dodecyl gallate. Emulsion samples were oxidized at 40 °C and the progress of oxidation was followed through quantitation of oxidized triacylglycerol monomers, dimers and oligomers. Results showed that Cas‐Lac emulsions were more stable to oxidation than T‐20 emulsions. In both types of emulsions, the most protective antioxidants were the compounds of lower polarity, namely, α‐tocopherol and dodecyl gallate. It was also found that substantial amounts of α‐tocopherol coexisted with significant polymerization, which was indicative of the heterogeneity of oxidation, i.e. differences of oxidation rate in oil droplets.
The effect of cooking and storage on the fatty acid profile of chicken breast
Authors: Conchillo Ana , Ansorena Diana , Astiasarán Iciar 
Published: May 2004

AbstractThe modification of the lipid profile of chicken breast after being cooked (grilled or roasted) and stored under different conditions (refrigeration Ta 4 °C t = 6 d, or freezing Ta‐18 °C t = 3 months, in aerobic or vacuum conditions) was studied. Grilling increased significantly the unsaturated/saturated (2.7) and polyunsaturated/saturated (1.4) ratios of fatty acids in comparison to raw samples (U/S = 1.7, P/S = 0.6) as a consequence of the use of sunflower oil. However, roasted samples did not significantly differ in these ratios (U/S = 1.8, P/S = 0.7) from raw samples. Fresh and stored raw and roasted samples did not show differences when a multivariate analysis was applied, although some significant differences were observed in their fatty acid profile. Frozen grilled samples (both aerobic and vacuum packed) showed differences from immediately cooked (t = 0) and refrigerated grilled samples.
Solvent and enzymatic extraction of Safou and Kolo oils
Authors: Dzondo‐Gadet Michel , Nzikou Jean Mathurin , Kimbonguila André , Linder Michel , Desobry Stéphane 
Published: May 2004

AbstractSafou (Dacryodes edulis) pulp oil became a new hope for fragile economics of central Africa countries. Raphia sese palm tree (Kolo) produces also an edible vegetable oil of well nutritious value. Various extraction methods were checked for the best yields. By soxhlet extractor using petroleum ether best yields were attained (47% for Safou and 52% for Kolo; dry weight) followed by the Bligh and Dyer method (43.2% for Safou and 50.8% for Kolo). No further improvement was obtained by the enzymatic treatment with Viscozym L (42% for Safou, 51.3% for Kolo). The application of enzyme added to the preservation of oil from oxidation during extraction process.
Structure and transformation of low‐temperature phases of 1,3‐distearoyl‐2‐oleoyl glycerol
Authors: Mykhaylyk Oleksandr O. , Castelletto Valeria , Hamley Ian W. , Povey Malcolm J. W. 
Published: May 2004

AbstractPolymorphic transformations of 1,3‐distearoyl‐2‐oleoyl glycerol (SOS) at low temperatures (10 °C–30 °C) have been studied by time‐resolved synchrotron X‐ray diffraction (XRD) measurements at small and wide angles. Three structures have been identified: α‐phase structure forms by quenching to 10 °C from the liquid state, a metastable structure formed simultaneously with α‐phase and γ‐phase formed at 30 °C during α‐melt‐mediated crystallisation as well as at the pre‐melting temperature (22.5 °C) of the α‐phase when the coexistence of two phases (α and γ) is observed. The metastable structure produces three broad peaks in XRD patterns at small angles (one strong and two weak peaks corresponding to d‐spacings of ∼4 nm, ∼12 nm and ∼1.5 nm respectively) and a peak in X‐ray diffraction patterns at wide angles (0.42 nm). A model is proposed for the metastable structure based on a combination of double‐ and triple‐chain packing of SOS molecules due to the similar length of alkyl chains (stearoyl and oleoyl) in the molecules.
Numerical analysis of moving interfaces using a level set method coupled with adaptive mesh refinement
Authors: Kohno Haruhiko , Tanahashi Takahiko 
Published: May 2004

AbstractA novel numerical scheme is developed by coupling the level set method with the adaptive mesh refinement in order to analyse moving interfaces economically and accurately. The finite element method (FEM) is used to discretize the governing equations with the generalized simplified marker and cell (GSMAC) scheme, and the cubic interpolated pseudo‐particle (CIP) method is applied to the reinitialization of the level set function. The present adaptive mesh refinement is implemented in the quadrangular grid systems and easily embedded in the FEM‐based algorithm. For the judgement on renewal of mesh, the level set function is adopted as an indicator, and the threshold is set at the boundary of the smoothing band. With this criterion, the variation of physical properties and the jump quantity on the free surface can be calculated accurately enough, while the computation cost is largely reduced as a whole. In order to prove the validity of the present scheme, two‐dimensional numerical simulation is carried out in collapse of a water column, oscillation and movement of a drop under zero gravity. As a result, its effectiveness and usefulness are clearly shown qualitatively and quantitatively. Among them, the movement of a drop due to the Marangoni effect is first simulated efficiently with the present scheme. Copyright © 2004 John Wiley & Sons, Ltd.
Generalized fourier analyses of the advection–diffusion equation—Part II: two‐dimensional domains
Authors: Voth Thomas E. , Martinez Mario J. , Christon Mark A. 
Published: May 2004

AbstractPart I of this work presents a detailed multi‐methods comparison of the spatial errors associated with the one‐dimensional finite difference, finite element and finite volume semi‐discretizations of the scalar advection–diffusion equation. In Part II we extend the analysis to two‐dimensional domains and also consider the effects of wave propagation direction and grid aspect ratio on the phase speed, and the discrete and artificial diffusivities. The observed dependence of dispersive and diffusive behaviour on propagation direction makes comparison of methods more difficult relative to the one‐dimensional results. For this reason, integrated (over propagation direction and wave number) error and anisotropy metrics are introduced to facilitate comparison among the various methods. With respect to these metrics, the consistent mass Galerkin and consistent mass control‐volume finite element methods, and their streamline upwind derivatives, exhibit comparable accuracy, and generally out‐perform their lumped mass counterparts and finite‐difference based schemes. While this work can only be considered a first step in a comprehensive multi‐methods analysis and comparison, it serves to identify some of the relative strengths and weaknesses of multiple numerical methods in a common mathematical framework. Published in 2004 by John Wiley & Sons, Ltd.
Consistent hybrid finite volume/element formulations: model and complex viscoelastic flows
Authors: Chandio M. S. , Sujatha K. S. , Webster M. F. 
Published: May 2004

AbstractThe accuracy and consistency of a new cell‐vertex hybrid finite element/volume scheme are investigated for viscoelastic flows. Finite element (FE) discretization is employed for the momentum and continuity equation, with finite volume (FV) applied to the constitutive law for stress. Here, the interest is to explore the consequences of utilizing conventional cell‐vertex methodology for an Oldroyd‐B model and to demonstrate resulting drawbacks in the presence of complex source terms on structured and unstructured grids. Alternative strategies worthy of consideration are presented. It is demonstrated how high‐order accuracy may be achieved in steady state by respecting consistency in the formulation. Both FE and FV spatial discretizations are embedded in the scheme, with FV triangular sub‐cells referenced within parent triangular finite elements. Both model and complex flow problems are selected to quantify and assess accuracy, appealing to analysis and experimental validation. The test problem is that of steady sink flow, a pure extensional flow, which reflects some of the numerical difficulties involved in solving more generalized viscoelastic flows, where both source and flux terms may contribute equally to stress propagation. In addition, a complex transient filament‐stretching flow is chosen to compute the evolution of stress fields within liquid bridges. Shortcomings of the various stress upwinding schemes are discussed in this context, whilst dealing with such free‐surface type problems. Here, stress fluctuation distribution alone is advocated, and a Lax‐scheme is found to deliver accuracy and stability to the computational results, comparing well with the literature. Copyright © 2004 John Wiley & Sons, Ltd.
Zero mass error using unsteady wetting–drying conditions in shallow flows over dry irregular topography
Authors: Brufau P. , García‐Navarro P. , Vázquez‐Cendón M. E. 
Published: May 2004

AbstractA wetting–drying condition (WDC) for unsteady shallow water flow in two dimensions leading to zero numerical error in mass conservation is presented in this work. Some applications are shown which demonstrate the effectiveness of the WDC in flood propagation and dam break flows over real geometries. The WDC has been incorporated into a cell centred finite volume method based on Roe's approximate Riemann solver across the edges of both structured and unstructured meshes. Previous wetting–drying condition based on steady‐state conditions lead to numerical errors in unsteady cases over configurations with strong variations on bed slope. A modification of the wetting–drying condition including the normal velocity to the cell edge enables to achieve zero numerical errors. The complete numerical technique is described in this work including source terms discretization as a complete and efficient 2D river flow simulation tool. Comparisons of experimental and numerical results are shown for some of the applications. Copyright © 2004 John Wiley & Sons, Ltd.
Enhanced in vitro invasiveness and drug resistance with altered gene expression patterns in a human lung carcinoma cell line after pulse selection with anticancer drugs
Authors: Liang Yizheng , O'Driscoll Lorraine , McDonnell Susan , Doolan Padraig , Oglesby Irene , Duffy Kieran , O'Connor Robert , Clynes Martin 
Published: May 2004

AbstractThe human lung carcinoma cell line DLKP was exposed to sequential pulses of 10 commonly used chemotherapeutic drugs (VP‐16, vincristine, taxotere, mitoxantrone, 5‐fluorouracil, methotrexate, CCNU, BCNU, cisplatin and chlorambucil); resulting cell lines exhibited resistance to the selecting agents (ranging approx. 1.5‐ to 36‐fold) and, in some cases, cross‐resistance to methotrexate (approx. 1.4‐ to 22‐fold), vincristine (1.6‐ to 262‐fold), doxorubicin (Adriamycin, approx. 1.1‐ to 33‐fold) and taxotere (approx. 1.1‐ to 36‐fold). Several of the variants displayed collateral sensitivity to cisplatin. A marked increase in in vitro invasiveness and motility was observed with variants pulsed with mitoxantrone, 5‐fluorouracil, methotrexate, BCNU, cisplatin and chlorambucil. There was no significant change in invasiveness of cells pulsed with VP‐16, vincristine, taxotere or CCNU. All of the pulse‐selected variants showed elevated levels of MDR‐1/P‐gp protein by Western blot analysis, although mdr‐1 mRNA levels were not increased (except for DLKP‐taxotere). In DLKP‐taxotere, MRP1 protein levels were also greatly elevated, but mrp1 mRNA levels remained unchanged. BCRP was upregulated in DLKP‐mitoxantrone at both the mRNA and protein levels. Gelatin zymography, Western blot and RT‐PCR showed that DLKP and its variants secreted MMPs 2, 9 and 13. MMP inhibition assays suggested that MMP‐2 plays a more important role than MMPs 9 and 13 in cell invasion of these DLKP drug‐resistant variants in vitro. These results indicate that drug exposure may induce not only resistance but also invasiveness in cancer cells. © 2004 Wiley‐Liss, Inc.