bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of zeolite‐incorporated poly(dimethyl siloxane) membranes for the pervaporation separation of isopropyl alcohol/water mixtures
Authors: Kittur Arjumand A. , Kariduraganavar Mahadevappa Y. , Kulkarni Srikant S. , Aralaguppi Mrityunjaya I. 
Published: March 2005

AbstractZSM‐5 zeolite‐incorporated poly(dimethyl siloxane) membranes were prepared, and the molecular dispersion of the zeolite in the membrane matrix was confirmed with scanning electron microscopy. After the swelling of the membranes was studied at 30°C, the membranes were subjected to the pervaporation separation of isopropyl alcohol/water mixtures at 30, 40, and 50°C. The effects of the zeolite loading and feed composition on the pervaporation performances of the membranes were analyzed. Both the permeation flux and selectivity increased simultaneously with increasing zeolite content in the membrane matrix. This was examined on the basis of the enhancement of hydrophobicity, selective adsorption, and the establishment of molecular sieving action. The membrane containing the highest zeolite loading (30 mass %) had the highest separation selectivity (80.84) and flux (6.78 × 10−2 kg m−2 h−1) at 30°C with 5 mass % isopropyl alcohol in the feed. From the temperature dependence of the diffusion and permeation values, the Arrhenius activation parameters were estimated. A pure membrane exhibited higher activation energy values for permeability (Ep) and diffusivity (ED) than zeolite‐incorporated membranes, and signified that permeation and diffusion required more energy for transport through the pure membrane because of its dense nature. Obviously, the zeolite‐incorporated membranes required less energy because of their molecular sieving action, which was attributed to the presence of straight and sinusoidal channels in the framework of the zeolite. For the zeolite‐incorporated membranes, the activation energy values obtained for isopropyl alcohol permeation were significantly lower than the water permeation values, and this suggested that the zeolite‐incorporated membranes had higher selectivity toward isopropyl alcohol. The Ep and ED values ranged between 21.81 and 31.12 kJ/mol and between 15.27 and 41.49 kJ/mol, respectively. All the zeolite‐incorporated membranes exhibited positive values of the heat of sorption, and this suggested that the heat of sorption was dominated by Henry's mode of sorption. sorption. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1377–1387, 2005
Effect of ionic salts on the processing of poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid) nanofibers
Authors: Kim Seon Jeong , Lee Chang Kee , Kim Sun I. 
Published: March 2005

AbstractWe studied the effect of nanofiber uniformity on electrospinning due to the charging of added ionic salts, as compared to the droplet current nonadded ionic salts and the charge‐to‐mass ratio of a highly conducting liquid. Various ionic salt concentrations were investigated. For an ionic salt concentration of 0.01 mol %, an applied electric field of 15 kV, and a spinning distance of 15 cm, the experimental results show that uniform nanofibers that did not contain any beads were synthesized with an optimal ionic salt concentration, when the convective current was two orders of magnitude higher than the nonadded ionic salt droplet current. The obtained fibers were uniform, with diameters of around 70 nm. We were able to produce these uniform nanofibers by controlling the balance between two opposing factors during electrospinning, by increasing the number of charge carriers and decreasing the viscosity of the solution. The effect of the ionic salts on the morphology of the electrospun nanofibers was investigated with field‐emission scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1388–1393, 2005
Preparation, characterization, and some properties of ionomers from a sulfonated styrene–butadiene–styrene triblock copolymer without gelation
Authors: Xie Hong‐Quan , Liu Dai‐Gang , Xie Dong 
Published: March 2005

AbstractThe conditions for the sulfonation of a highly unsaturated styrene–butadiene–styrene triblock copolymer (SBS) in cyclohexane containing a small amount of acetone with acetyl sulfate made by sulfuric acid and acetic anhydride without gelation were studied. After neutralization with metallic ions, the ionomers were characterized with IR spectrophotometry, dynamic mechanical analysis, and transmission electron microscopy. The melt flow, solution properties, and mechanical properties of the ionomers were studied. The results showed that gelation occurred during the sulfonation of SBS in cyclohexane at a 5–10% concentration without acetone, whereas in the presence of 5–10 vol % acetone, sulfonation proceeded smoothly without gelation. Transmission electron microphotographs of the lead ionomer indicated the presence of ionic domains. A dynamic mechanical spectrum showed the presence of three transition temperatures: −82.9, 68, and 96.5°C. The melt viscosity of the ionomer increased with the sulfonate content. The melt viscosity of the different ionomers neutralized with different cations seemed to decrease with decreasing ionic potential for both monovalent cations and divalent cations The solution viscosity of the sodium‐sulfonated ionomer increased with increasing sulfonate content. The ionomer still behaved as a thermoplastic elastomer and showed better mechanical properties than the original SBS. The tensile strength of the different ionomers decreased as follows. For the monovalent cations, it decreased with decreasing ionic potentials: Li+ > Na+ > K+. For the divalent cations, it decreased with increasing ionic potentials: Pb2+ > Zn2+ > Mg2+. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1398–1404, 2005
An efficient way to improve the mechanical properties of polypropylene/short glass fiber composites
Authors: Xie Hong‐Quan , Zhang Shu , Xie Dong 
Published: March 2005

AbstractEnhancement of tensile strength, impact strength, and flexural strength of polypropylene/short glass fiber composites by treating the glass fibers with coupling agent, mixing with maleated polypropylene (MPP) for compatibilization and adhesion, and with nucleating agent for improvement of polypropylene crystallization was studied. The results showed that both the silane coupling agent and MPP enhance tensile strength, impact strength, and flexural strength. In the absence of MPP, the effect of silane coupling agent on the mechanical properties of the composites decreases in the following order: alkyl trimethoxy silane (WD‐10) > γ‐methacryloxypropyl trimethoxysilane (WD‐70) > N‐(β‐aminoethyl)‐γ‐aminopropyl trimethoxysilane (WD‐52), whereas in the presence of MPP, the order changes as follows: WD‐70 > WD‐10 > WD‐52. When the glass fibers were treated with WD‐52, 4,4‐diamino‐diphenylmethane bismaleimide (BMI) can further enhance the mechanical properties of the composite. The three kinds of strengths increase with MPP amount to maximum values at 5% MPP. As a nucleating agent, adipic acid is better than disodium phthalate in improving the mechanical properties, except for the notched impact strength. Wide‐angle X‐ray diffraction showed that the adipic acid is an α‐type nucleating agent, whereas disodium phthalate is a β‐type nucleating agent. Blending with styrene–butadiene rubber can somewhat improve the notched impact strength of the composites, but severely lowers the tensile strength and bending strength. Scanning electron micrographs of the broken surface of the composite showed greater interfacial adhesion between the glass fibers and polypropylene in the modified composite than that without modification. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1414–1420, 2005
Modification of cellulose fiber with silk sericin
Authors: Kongdee Arunee , Bechtold Thomas , Teufel Linda 
Published: March 2005

AbstractCellulose fiber surface was modified with silk sericin (or simply, sericin). Sericin fixation on cellulose was confirmed by environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectrophotometry–attenuated total reflectance (FTIR‐ATR). Sericin content in finished samples was estimated by dyeing treated fabrics with an acid dye, Supranol Bordeaux B, and determining K/S and L values of the dyed fabrics. The treated fabrics were tested for free formaldehyde content, crease recovery, tensile strength, electrical resistance, water retention, and biocidal activity. From ESEM and FTIR‐ATR results, it was found that sericin coated onto cotton surfaces as a film. Increasing sericin content in the finishing solution increased the amount of coated sericin, and a greater depth of color in dyed samples and reduced free formaldehyde content in treated samples were observed. The sericin content in samples was found to have a negligible influence on tensile strength and crease recovery angle. With increasing sericin content, electrical resistivity of the samples dramatically decreased and water retention increased, indicating that sericin‐treated fabrics may be comfortable to wear because of its maintenance of moisture balance with respect to human skin. Because cotton textile coated with sericin exhibited low formaldehyde content and no biocidal activity against Klebsiella pneumoniae and Staphylococcus aureus, the fabric may reduce skin irritation and disturbance of physiological skin flora arising from textile contact. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1421–1428, 2005
Binolam–AlCl: A Two‐Centre Catalyst for the Synthesis of Enantioenriched Cyanohydrin O‐Phosphates
Authors: Baeza Alejandro , Nájera Carmen , Sansano José M. , Saá José M. 
Published: March 2005

AbstractThe enantioselective synthesis of cyanohydrin O‐phosphates by using in situ generated bifunctional catalysts (R)‐ or (S)‐3,3′‐bis(diethylaminomethyl)‐1,1′‐binaphthol–aluminium chloride (binolam–AlCl) is reported. The reaction, which can be described as an overall cyano‐O‐phosphorylation of aldehydes, has a wide scope and applicability. Evidence is also provided, including ab initio and DFT calculations, in support of supported by the Lewis acid/Brønsted base (LABB) dual role of the catalyst in inducing first the key enantioselective hydrocyanation, which is then followed by O‐phosphorylation. A brief screening of the synthetic usefulness of the resulting cyanohydrin O‐phosphates unveiles some interesting applications. Among them, chemoselective hydrolysis, reduction and palladium‐catalysed nucleophilic allyl substitution, thereby leading to enantiomerically enriched α‐O‐phosphorylated α‐hydroxy esters, β‐amino alcohols and γ‐cyanoallyl alcohols, respectively. Naturally occurring (−)‐tembamide and (−)‐aegeline are synthesised accordingly.
Non‐Covalent Interactions of Organic Halogen Compounds with Aromatic Systems – Analyses of Crystal Structure Data
Authors: Swierczynski Dariusz , Luboradzki Roman , Dolgonos Grigori , Lipkowski Janusz , Schneider Hans‐Jörg 
Published: March 2005

AbstractThe Cambridge Structural Database showed in mid 2002 about 20.000 structures containing halogen atoms and aryl rests with distances d between the aryl center and the halogen atom, which would allow both hydrogen bonds with the aromatic hydrogens and/or van der Waalsinteractions with the π‐cloud. The latter are characterized by short distances d and by small angles α between the vector along the aryl centroid–halogen line and the perpendicular vector originating in the aryl center (the plane normal). The cases with d < 3.0 Å for F; and d < 3.5 Å for Cl, Br or I (outliers neglected), and α ≈ 10 ± 5°, indicating predominating van der Waals forces, amount to several hundreds. The majority of fragments exhibit larger d and α values, in line with avoidance of electrostatic repulsion between the negative partial charges of the halogens and the π‐cloud center, and with an increasing electrostatic attraction with the aromatic hydrogen atoms. The corresponding hydrogen bonds are characterized by longer distances d and by angle values of α > 60° (about 40 % of the fragments), with only very few cases close to linear hydrogen bonds (then with α = 90°). Compounds containing metal–halogen bonds were omitted in view of possible strong orientational interferences. The structures were screened with four different halogen binding modes, all of them containing the halogen attached to a carbon atom, but with different hybrizations at the connecting carbon centers. The results show only small differences in the distance distributions, with a slight preference for smaller α values for sp2 frameworks. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
An Asymmetric Biaryl Suzuki Cross‐Coupling Reaction: Stereogenic Benzylic Carbinols as Chiral Auxiliaries
Authors: Broutin Pierre‐Emmanuel , Colobert Françoise 
Published: March 2005

AbstractAsymmetric biaryl Suzuki coupling reactions were performed with various aryl‐ or naphthylhalide‐bearing enantiomerically pure benzylic alcohols and aryl‐ or naphthylboronic acids (or esters). The stereogenic benzylic alcohol was introduced by diastereoselective reduction of the arylhalide bearing a β‐keto sulfoxide. In the presence of Pd(OAc)2/CsF and dppf or PPh3 excellent yields and atropodiastereoselectivities were obtained. The absolute configurations of the biaryls were determined by X‐ray crystallography and 1H NMR NOESY experiments. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Capillary electrophoresis – mass spectrometry: Survey on developments and applications 2003–2004
Authors: Schmitt‐Kopplin Philippe , Englmann Matthias 
Published: March 2005

AbstractThe major developments and applications related to CE‐MS over the last two years (2003–2004) and most of the reviews and applications found in the ISI Web of Science and publisher data bases are presented in a tabulated way. This article complements our previous review “Capillary electrophoresis – mass spectrometry: 15 years of developments and applications”, Electrophoresis, 2003, 24, 3837–3867 [1] for the last two years 2003–2004. All cited articles were analyzed in a way to illustrate (i) in which journals CE‐MS‐related papers were mostly found over the last decades and (ii) which commercial CE‐, MS‐instrumentations or CE‐MS combinations were mostly used in the European, Asian, and American continent. Additionally, like it was done in our last review, the reader will rapidly find applications classified as forensics, environment, bioanalytics, pharmaceutics, and metabolites.
Use of becaplermin in the closure of pharyngocutaneous fistulas
Authors: Jakubowicz David M. , Smith Richard V. 
Published: March 2005

AbstractBackground.We report on the contribution of recombinant platelet‐derived growth factor‐BB (becaplermin) in treating recalcitrant postlaryngectomy fistulas in two patients with head and neck cancer.Methods.Topical becaplermin was applied daily, with periodic wound assessment and photodocumentation.Results.The two patients with persistent fistula refractory to conventional management have demonstrated rapid improvement after topical application of becaplermin. Each wound exhibited an exuberant granulation response, with a 50% decrease in the size of wound at 1 week. The patients experienced eventual closure, with none having local recurrence of their cancer at 2 years' follow‐up.Conclusions.Becaplermin seems to be a promising addition to traditional methods of treatment for postlaryngectomy fistulas. In patients with delayed healing, future studies will be required to determine the overall efficacy of such biologic response modifiers in the treatment of pharyngocutaneous fistulas and other chronic wounds of the head and neck. © 2005 Wiley Periodicals, Inc. Head Neck 27: XXX–XXX, 2005
Inhibition of monocyte adhesion on brain‐derived endothelial cells by NF‐kappaB decoy/polyethylenimine complexes
Authors: Fischer Dagmar , Bhattacharya Raktima , Osburg Berit , Bickel Ulrich 
Published: March 2005

AbstractBackgroundThe nuclear factor (NF)‐κB plays a key role in inflammatory reactions of the endothelium by controlling the expression of surface‐adhesion molecules and other inflammatory mediators, which facilitate the attachment of monocytes and lymphocytes to the endothelial surface. We investigated the inhibition of monocyte adhesion by NF‐κB transcription factor decoys complexed with polyethylenimines (PEIs) of different molecular weights and structures (800, 25, and 2.7 kDa PEI).MethodsFormation, size and stability of the PEI/decoy complexes were investigated by polyacrylamide gel electrophoresis and photon correlation spectroscopy. The efficiency of the complexes was studied in a cell adhesion assay using the murine brain‐derived endothelial cell line bEnd5, activated with lipopolysaccharide as inflammatory model. U‐937 monocytes were fluorescently labeled with BCECF‐AM to permit quantitative measurement of adhesion. Expression of endothelial cell adhesion molecules was determined at the mRNA level by RT‐PCR and at the protein level by ELISA.ResultsDepending on the N/P ratio, decoys formed complexes of <200 nm in size with all PEIs, which were stable against degradation by nucleases and dissociation by albumin. Treatment of bEnd5 and U‐937 cells with NF‐κB decoys complexed with 25 and 2.7 kDa PEI reduced the number of adherent U‐937 cells and decreased the levels of ICAM‐1 and VCAM‐1 mRNA and protein. The effects were specific, time‐dependent and increased with higher N/P ratios of complexes and lower cytotoxicity of polymers. In contrast, the efficiency of the 800 kDa PEI was much lower compared to the other polymers.ConclusionsComplexes of NF‐κB decoy and PEIs effectively inhibited the adherence of monocytes on endothelial cells, which could be a promising strategy for the treatment of inflammatory diseases. Copyright © 2005 John Wiley & Sons, Ltd.
Dynamic Mechanical and Thermal Properties of Phenylethynyl‐Terminated Polyimide Composites Reinforced With Expanded Graphite Nanoplatelets
Authors: Cho Donghwan , Lee Sangyeob , Yang Gyeongmo , Fukushima Hiroyuki , Drzal Lawrence T. 
Published: March 2005

AbstractSummary: This article reports on the dynamic mechanical and thermal properties of thermosetting phenylethynyl‐terminated polyimide (PETI‐5) composites reinforced with expanded graphite (EG) nanoplatelets having various average particle sizes and content. The EG nanoplatelets with varying particle sizes were prepared by different pulverization techniques through intercalation and exfoliation of natural graphite flakes. The effect of the EG particle size and concentration of the thermal behavior of PETI‐5/EG composites was investigated with several thermal analysis methods (DMA, TMA, and DSC). The storage modulus dynamic mechanical properties and glass transition temperature significantly increased with increasing concentration of EG nanoreinforcements regardless of size. The coefficient of thermal expansion significantly decreased, especially in the glass transition region.
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An Investigation of Friction and Wear Behaviors of Polyimide/Attapulgite Hybrid Materials
Authors: Lai Shi‐Quan , Yue Li , Li Tong‐Sheng , Liu Xu‐Jun , Lv Ren‐Guo 
Published: March 2005

AbstractSummary: PI/AT hybrid materials were prepared by blending of poly(amic acid) and purified AT as a type of fibrillar clays. The friction and wear behaviors of the PI hybrids were evaluated on a ball‐on‐disc wear tester. The particle size of AT in the hybrid containing 5 wt.‐% AT was about 10–100 nm in diameter and 100–1 000 nm in length. Tensile tests on the PI hybrids showed that the strength and the toughness of PI/AT hybrid materials were improved simultaneously when the content of AT was less than 5 wt.‐%. The friction coefficient and wear rate of the PI hybrids first decreased and then increased with increasing content of AT. The wear rate of the hybrid containing 3 wt.‐% AT was more than 6 times lower than that of pure PI. SEM examination of worn surfaces showed that type of wear changed from adhesive wear of pure PI into abrasive wear of the PI hybrids with adding AT to PI matrix. Debris analysis suggested that AT as filler inside the PI matrix could prevent the formation of bigger debris and a chemical reaction that occurred during the friction process of pure PI but not in the hybrids.A plot of the calculated wear rate versus filler content.magnified imageA plot of the calculated wear rate versus filler content.
Cover: Macromol. Mater. Eng. 3/2005
Authors: Hirao Yoshitoshi , Ohkawa Kousaku , Yamamoto Hiroyuki , Fujii Toshihiro 
Published: March 2005

Cover: The picture on the cover shows morphological comparisons of the gellan chitosan hybrid fiber (left( and the novel human hair protein‐gellan‐chitosan hybrid fiber (right(, which were prepared by new combined technologies of (i( “Shindai method” for high‐efficiency extraction of human hair protein and (ii( “Watery hybridization spinning” that allows to produce the water‐insoluble hybrid fibers from two aqueous solutions of counter‐charged polymers.Further details can be found in the Full paper by Y. Hirao, K. Ohkawa, H. Yamamoto, and T. Fujii* on page 165.
Efficient finite element formulation for geothermal heating systems. Part I: steady state
Authors: Al‐Khoury R. , Bonnier P. G. , Brinkgreve R. B. J. 
Published: March 2005

AbstractThis paper presents the development of a computationally efficient finite element tool for the analysis of 3D steady state heat flow in geothermal heating systems. Emphasis is placed on the development of finite elements for vertical borehole heat exchangers and the surrounding soil layers. Three factors have contributed to the computational efficiency: the proposed mathematical model for the heat exchanger, the discretization of the spatial domain using the Petrov–Galerkin method and the sequential numerical algorithm for solving the resulting system of non‐linear equations. These have contributed in reducing significantly the required number of finite elements necessary for describing the involved systems. Details of the mathematical derivations and some numerical examples are presented. Copyright © 2005 John Wiley & Sons, Ltd.
Modified immunohistological staining allows detection of Ziehl–Neelsen‐negative Mycobacterium tuberculosis organisms and their precise localization in human tissue
Authors: Ulrichs Timo , Lefmann Michael , Reich Maja , Morawietz Lars , Roth Andreas , Brinkmann Volker , Kosmiadi George A , Seiler Peter , Aichele Peter , Hahn Helmut , Krenn Veit , Göbel Ulf B , Kaufmann Stefan HE 
Published: March 2005

AbstractThe diagnosis of mycobacterial infection depends on the Ziehl–Neelsen (ZN) stain, which detects mycobacteria because of their characteristic acid‐fast cell wall composition and structure. The histological diagnosis of tuberculosis (TB) comprises various aspects: (1) sensitive detection of mycobacteria; (2) precise localization of mycobacteria in the context of granulomatous lesions; (3) ‘staging’ of disease according to mycobacterial spread and granulomatous tissue integrity. Thus, detection of minute numbers of acid‐fast bacteria in tissue specimens is critical. The conventional ZN stain fails to identify mycobacteria in numbers less than 104 per ml. Hence many infections evade diagnosis. PCR is highly sensitive, but allows neither localization within tissues nor staging of mycobacterial disease, and positive findings frequently do not correlate with disease. In this study, an anti‐Mycobacterium bovis bacille Calmette–Guérin polyclonal antiserum (pAbBCG) was used to improve immunostaining, which was compared to the ZN stain in histological samples. Screening of tissue samples including lungs, pleural lesions, lymph nodes, bone marrow, and skin for mycobacterial infection revealed that pAbBCG staining detects infected macrophages harbouring intracellular mycobacteria or mycobacterial material as well as free mycobacteria that are present at low abundance and not detected by the ZN stain. The positive pAbBCG staining results were confirmed either by PCR analysis of microdissected stained tissue or by culture from tissue. This immunostaining approach allows precise localization of the pathogen in infected tissue. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.