bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a photoresponsive cell culture surface: Regional enhancement of living‐cell adhesion induced by local light irradiation
Authors: Tada Yuichi , Sumaru Kimio , Kameda Mitsuyoshi , Ohi Katsuhide , Takagi Toshiyuki , Kanamori Toshiyuki , Yoshimi Yasuo 
Published: January 2006

AbstractUsing a functional polymer containing nitrospirobenzopyran residues and poly(ethylene glycol), we developed a photoresponsive cell culture surface (PRCS), at which the cell adhesion can be enhanced locally by UV light irradiation (350–400 nm, 35 mW/cm2, 5 min) even on the region where living cells exist. Cell adhesion was evaluated by observing BALB/3T3 fibroblasts, which had been seeded on PRCS and then irradiated with UV light regionally, after 12 h incubation and subsequent washing to remove scarcely adhering cells. As a result, it was confirmed that the number of remaining cells in irradiated region was at most 2.5 times greater than that in nonirradiated regions, suggesting the implementation of a novel scheme to manipulate living cells individually by light irradiation in a parallel and simultaneous manner. Influence of the composition of the polymer material consisting the substrate surface was also investigated systematically. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 495–499, 2006
Rheology of poly(N‐vinyl pyrrolidone)–poly(ethylene glycol) adhesive blends under shear flow
Authors: Feldstein Mikhail M. , Kulichikhin Valery G. , Kotomin Sergey V. , Borodulina Tatiana A. , Novikov Mikhail B. , Roos Alexandra , Creton Costantino 
Published: January 2006

AbstractThe rheological properties of adhesive miscible blends of high‐molecular‐weight poly(N‐vinyl pyrrolidone) (PVP) with short‐chain poly(ethylene glycol) (PEG) under oscillatory and steady‐state shear flow have been examined with dynamic mechanical and squeezing‐flow analysis. The latter allows the rheological characterization of adhesive blends under conditions modeling adhesive‐bond formation as a fixed compressive force is applied to an adhesive film. The most adhesive PVP blend with 36 wt % PEG has been established to flow like a viscoplastic (yield stress) liquid with a power‐law index of about 0.12. The study of the apparent yield stress as a function of the PVP–PEG composition, content of sorbed water, molecular weight of PVP, and temperature shows that the occurrence of a yield stress in the blends results most likely from a noncovalent crosslinking of PVP macromolecules through short PEG chains by means of hydrogen bonding of both terminal OH groups of PEG to the complementary functional groups in PVP monomer units. A molecular mechanism of PVP–PEG interaction was established earlier by direct and independent methods. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 522–537, 2006
Novel self‐disinfecting surface
Authors: McCubbin P. J. , Forbes E. , Gow M. M. , Gorham S. D. 
Published: January 2006

AbstractThe colonization of medical devices by micro‐organisms is an ongoing problem, particularly as many strains of bacteria are becoming resistant to antibiotics. One method by which this could be addressed is the production of a surface that will kill bacteria on contact without releasing the disinfecting agent into solution. Self‐disinfecting surfaces were prepared in which a quaternary ammonium salt was covalently bound onto a polyethylene film by a stable linkage. To achieve this, a low‐density polyethylene film was treated with glow discharge followed by the graft polymerization of acrylic acid. The acid chloride derivative was then prepared. α,ω‐Dibromoalkanes of various chain lengths were reacted with potassium phthalimide to form anN‐alkylphthalimido group, and this was followed by an excess of piperidine to produce a tertiary amino group at the opposite end of the alkyl chain. The hydrolysis of the phthalimido group produced a primary amino function that was coupled to the grafted poly(acryl chloride). A reaction with octadecyl bromide resulted in the production of a quaternary ammonium salt. The amide linkage by which the quaternary ammonium salt was attached to the polymer was stable, and no release of the disinfecting moiety took place in solution. Soluble compounds containing a similar quaternary ammonium function were prepared through the reaction of the primary amine group with acetyl chloride rather than the polymeric acid chloride to form substitutedN‐acetamides. In a microbiological pilot study, both the polymer‐bound and soluble quaternary ammonium salts were effective against suspensions ofStaphylococcus aureus,Escherichia coli, andSaccharomyces cerevisiae. The results show that a self‐disinfecting surface can be produced in which the quaternary ammonium function is an effective bacteriocide that remains bound to the polymer surface. In addition, the materials were toxic to a mammalian cell line (Chinese hamster ovary cells). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 381–389, 2006
Covalent attachment of quaternary ammonium compounds to a polyethylene surface via a hydrolyzable ester linkage: Basis for a controlled‐release system of antiseptics from an inert surface
Authors: McCubbin P. J. , Forbes E. , Gow M. M. , Gorham S. D. 
Published: January 2006

AbstractThe colonization of medical devices such as catheters, topical wound dressings, and surgical implants by micro‐organisms is an ongoing problem, particularly as many strains of bacteria are becoming resistant to antibiotics. Such a problem may be addressed by a material surface that is able to provide a slow release of a disinfectant during its period of usage. To achieve this objective, a novel material was prepared in which a quaternary ammonium salt was covalently bound onto a polyethylene backbone via a hydrolyzable ester linkage, which provided a slow release of the disinfecting agent. A low‐density polyethylene film was treated with glow discharge followed by the graft polymerization of acrylic acid. A tertiary amine function was introduced onto the film by the esterification of the carboxylic acid groups, via an acid chloride intermediate, with 4‐hydroxy‐N‐methyl piperidine. The tertiary amine on the piperidine was then quaternized with a series of alkyl bromides of various chain lengths. The quaternary ammonium salt was released slowly by the hydrolysis of the ester bond over a 4‐h period. To test the efficacy of the quaternary ammonium function itself, soluble compounds were prepared as follows. 4‐Hydroxy‐N‐methyl piperidine was esterified with acetic anhydride and a corresponding series of quaternary ammonium salts prepared again by a reaction with alkyl bromides of various chain lengths. A preliminary microbiological survey of the materials included an investigation of the effect of the chain length as well as the efficacy of the soluble quaternary salts themselves. As expected, only the longer alkyl chains provided quaternary ammonium salts with bactericidal properties, chain lengths of less than 10 carbon atoms proving ineffective. Both the polymer‐bound and soluble long‐chain quaternary ammonium salts were effective against suspensions of Staphylococcus aureus and Escherichia coli. The results therefore indicate that such a system may well be useful in the development of biomedical materials such as surgical implants or dressings in which a slow release of a disinfectant or other physiologically active agent such as an anti‐inflammatory drug may be required. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 538–545, 2006
Preparation and application of acrylonitrile‐grafted cyanoethyl cellulose for the removal of copper (II) ions
Authors: Kamel S. , Hassan E. M. , El‐Sakhawy M. 
Published: January 2006

AbstractCyanoethyl cellulose (CE‐Cell) with two different degrees of substitution of 0.37 and 0.60 were prepared from cotton linter. The ionic‐xanthate method was used to graft the acrylonitrile onto CE‐Cell to form acrylonitrile‐grafted cyanoethyl cellulose (GCE‐Cell). The conditions of grafting such as sodium hydroxide concentration, grafting time, monomer concentration, and temperature were optimized. The hydrolyzed CE‐Cell and GCE‐Cell were applied for the adsorption of copper (II) ions from aqueous solution. IR spectroscopy was also used for further evaluation of CE‐Cell and GCE‐Cell. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 329–334, 2006
Reversible addition–fragmentation chain transfer polymerization of styrene with benzoimidazole dithiocarbamate as a reversible addition–fragmentation chain transfer agent
Authors: Yin Haisu , Zhu Xiulin , Zhou Di , Zhu Jian 
Published: January 2006

AbstractTwo novel dithiocarbamates [2‐Y‐benzoimidazole‐1‐carbodithioic acid benzyl esters: Y = methyl (1b) or phenyl (1c)] were synthesized and successfully used in the reversible addition–fragmentation chain transfer (RAFT) polymerization of styrene in bulk with thermal initiation. The effects of the temperatures and concentration ratios of the styrene and RAFT agents on the polymerization were investigated. The results showed that the polymerization of styrene could be well controlled in the presence of 1b or 1c. The linear relationships between ln([M]0/[M]) and the polymerization time (where [M]0 is the initial monomer concentration and [M] is the monomer concentration) indicated that the polymerizations were first‐order reactions with respect to the monomer concentration. The molecular weights increased linearly with the monomer conversion and were close to the theoretical values. The molecular weight distributions [weight‐average molecular weight/number‐average molecular weight (Mw/Mn)] were very narrow from 5.3% conversion up to 94% conversion (Mw/Mn < 1.3). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 560–564, 2006
Flame retardancy of a polycarbonate–polydimethylsiloxane block copolymer: The effect of the dimethylsiloxane block size
Authors: Nodera Akio , Kanai Toshitaka 
Published: January 2006

AbstractThis report describes the flame retardancy of a polycarbonate (PC)–polydimethylsiloxane (PDMS) block copolymer with a dimethylsiloxane (DMS) block size of 15–350 units, and the effects of the block size and amount of DMS on the flame retardancy are studied. PC–PDMS block copolymers with DMS units of 40–130 had high limiting oxygen index values with 1.0 wt % PDMS. The PDMS block size influenced the PDMS dispersibility in PC, and a moderate PDMS dispersion (ca. 50 nm) caused high flame retardancy for PC. These PC–PDMS block copolymers could form a lot of fine bubbles in the role of good thermal insulators through the reaction of PC and PDMS in combustion. Furthermore, the silica particles from PDMS remained mostly on the surface of the char, so the amount of char with high oxidation resistance increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 565–575, 2006
Surface segregation of polyethylene in low‐density polyethylene/ethylene–propylene–diene rubber blends: Aspects of component structure
Authors: Bieliński Dariusz M. , Kaczmarek łukasz 
Published: January 2006

AbstractAspects of the molecular weight and its distribution, the branching of low‐density polyethylene (LDPE), and the molecular composition of the ethylene–propylene–diene rubber (EPDM) matrix are presented in this article in terms of their influence on the surface segregation of polyethylene (PE) in elastomer/plastomer blends. All of the PEs studied, despite different weight‐average molecular weights and degrees of branching, segregated to the surface of the LDPE/EPDM blends. Atomic force microscopy pictures demonstrated defective crystalline structures on the surface of the blends, which together with a decrease in the degrees of their bulk crystallinity and a simultaneous increase in their melting temperatures, pointed to a low molecular weight and a defective fraction of PE taking part in the surface segregation. The extent of segregation depended on the molecular structure of the EPDM matrix, which determined the miscibility of the components on a segmental level. The higher the ethylene monomer content in EPDM was, the lower was the PE content in the surface layer of the blends. The composition and structure of the surface layer was responsible for its lower hardness in comparison with the bulk of the blends studied. The surface gradient of the mechanical properties depended on the physicochemical characteristics of the components and the blend composition, which created the possibility of tailoring the LDPE/EPDM blends to dedicated applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 625–633, 2006
Synthesis and characterization of soluble hyperbranched polymer via initiator‐fragment incorporation radical polymerization of divinylbenzene with dimethyl 2,2′‐azobisisobutyrate
Authors: Hirano Tomohiro , Higashida Naoki , Wang Hongwei , Sato Makiko Seno Tsuneyuki 
Published: January 2006

AbstractThe homopolymerization of divinylbenzene (DVB) as an excellent crosslinker (0.20 mol/L) with dimethyl 2,2′‐azobisisobutyrate (MAIB) proceeded homogeneously without any gelation at 80°C in benzene when the MAIB concentrations as high as 0.30–0.50 mol/L were used, yielding soluble polymers. In the polymerization at the concentrations of [DVB] = 0.20 mol/L and [MAIB] = 0.50 mol/L, the polymer yield increased with time and leveled off over 90 min. The molecular weight and molecular weight distribution increased with polymer yield. The vinyl groups of DVB were observed to be almost completely consumed in about 80 min, by FT near‐IR spectroscopic analysis. The homogeneous polymerization system involved ESR‐observable polymer radical, the concentration of which increased with time up to 3.4 × 10−5 mol/L. The polymer formed in the polymerization for 2 h consisted of 46 mol % of DVB unit and 54 mol % of the methoxycarbonylpropyl group as MAIB fragment, indicating that an initiator‐fragment incorporation radical polymerization proceeds in the present polymerization. The polymer was soluble in benzene, tetrahydrofuran, ethyl acetate, chloroform, acetone, and N,N‐dimethylformamide, while it was insoluble in n‐hexane, acetonitrile, dimethyl sulfoxide, methanol, and water. The results of the multiangle laser light scattering and viscometric measurements revealed that the individual polymer molecules were formed as hyperbranched polymer nanoparticles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 664–670, 2006
Study on preparation of protein‐imprinted soft‐wet gel composite microspheres with magnetic susceptibility and their characteristics. I. Preparation and particle morphology
Authors: Lu Shulai , Cheng Guoxiang , Pang Xingshou 
Published: January 2006

AbstractProtein‐imprinted soft‐gel composite microspheres with magnetic susceptibility (MS‐PIGMs) were prepared by inverse suspension polymerization, using Fe3O4 particles as magnetically susceptible component, acrylamide (AM) and N,N′‐methylenebisacrylamide (BisAM) as polymeric matrix components, toluene as solvent, and bovine serum albumin (BSA) and lysozyme (Lyz) as templates, respectively. The surface morphology of MS‐PIGMs was observed by environmental scanning electron microscope (ESEM) and scanning electron microscope (SEM). The effects of the kinds and amount of dispersants, stirring rate, the amount and adding methods of initiator, the amount of Fe3O4 and monomer concentration on particle morphology of MS‐PIGMs, as well as the effects of crosslinking degree on swelling ratio and particle morphology in wet condition were investigated in detail. ESEM and SEM photographs showed that the resulting MS‐PIGMs were all spheroid form and had large quantity of regularly distributed pores in wet condition, which close in dry condition, and the experimental results indicated that all the affecting factors had obvious effects on particle morphology of MS‐PIGMs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 684–694, 2006
Elastic properties of natural rubber tubes produced by dip‐coating
Authors: Neves‐Junior W. F. P. , Graeff C. F. de O. , Ferreira M. , Mulato M. , Bernardes M. S. , Coutinho‐Netto J. 
Published: January 2006

AbstractThe mechanical properties of rubber tubes produced by dip‐coating technique and the influence of the fabrication process on their structural properties were evaluated. Cyclic tension versus deformation tests were performed to investigate the elastic properties of the samples and to understand the changes in rubber tubes behavior under repetitive stress. The effect of the wall thickness on the elastic response of the tubes was also studied. The mechanical properties of opened tubes were also investigated for transversal and longitudinal directions to evaluate the influence of the fabrication process on the alignment of the polymer chains. This investigation indicated that the fabricated tubes are resistant and extremely elastic. They can be elongated up to 800% of its initial length before rupture, and thicker tubes are a bit more resistant to elongation than the thinner ones. In addition, the fabricated tubes have an anisotropic structure due to the fabrication process. Finally, natural rubber tubes may have a great potential to be used as vascular prosthesis, or in other applications that require a large range of resistance and elasticity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 702–707, 2006
Combination of atomic force microscopy and chemical hydrolysis to characterize degradable regions in polymer blends
Authors: Gu X. , Raghavan D. , Emekalam A. 
Published: January 2006

AbstractIn this study, we demonstrate the usefulness of chemical‐based method in combination with atomic force microscopy (AFM) to characterize the degradable regions in a wide range of polymer blends. This approach is based on selective hydrolysis of one of the components in a multiple‐phase system, and the ability of AFM to provide nanoscale lateral information about the different phases in the polymer system. Composite films containing different percentage of hydrolyzable polymer were either melt processed or solution casted and then exposed to a hydrolytic acidic environment. Tapping mode AFM was used to analyze the samples before and after hydrolysis. Dramatic topographic changes such as pits were observed on the acid exposed samples, indicating that the degradation was localized and the more susceptible component in the blend was hydrolyzed. Additionally, the progressive hydrolysis of the composites was studied by attenuated total reflection FTIR (ATR‐FTIR) analyses to confirm the AFM results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 726–733, 2006
Synthesis and Preliminary Biological Evaluation of 2′‐Substituted 2‐(3′‐Carboxybicyclo[1.1.1]pentyl)glycine Derivatives as Group I Selective Metabotropic Glutamate Receptor Ligands
Authors: Pellicciari Roberto , Filosa Rosanna , Fulco Maria Carmela , Marinozzi Maura , Macchiarulo Antonio , Novak Clemens , Natalini Benedetto , Hermit Mette Brunsgaard , Nielsen Søren , Sager Thomas Nikolaj , Stensbøl Tine Bryan , Thomsen Christian 
Published: January 2006

AbstractThe first series of 2′‐substituted 2‐(3′‐carboxybicyclo[1.1.1]pentyl)glycine derivatives, (2R)‐ and (2S)‐(2′,2′‐dichloro‐3′‐carboxybicyclo[1.1.1]pentyl)glycine (10) and (11), and 2‐(2′‐chloro‐3′‐carboxybicyclo[1.1.1]pentyl)glycine (12) were synthesized and evaluated as mGluR ligands. Compounds 11 and 12 were shown to be competitive group I mGluR antagonists. These results are also discussed in light of docking studies with both the active (closed) and inactive (open) conformations of mGluR1.
Visual adaptations in the night‐active wasp Apoica pallens
Authors: Greiner Birgit 
Published: January 2006

AbstractThe apposition compound eye of the nocturnal polistine wasp Apoica pallens shows, in comparison to the closely related diurnal wasp Polistes occidentalis, specific adaptations to vision at low light intensities. When considering recent work on nocturnal and diurnal bees, general principles for dim‐light vision in hymenopterans become evident: The rhabdom diameters in nocturnal bees and wasps are 4 times wider compared to their diurnal relatives, leading to wide receptive fields, which in turn account for a 25‐fold higher optical sensitivity. Interestingly, the rhabdom diameters in both nocturnal bees and wasps measure 8 μm, which may represent the maximum width for nocturnal hymenopteran apposition eyes. A ratio of 1.8 times larger eyes is present in the nocturnal bees and wasps, which in A. pallens is achieved by increasing the facet number, instead of enlarging the facets, as in nocturnal bees. Although this initially indicates spatial resolution to be important for the nocturnal wasp, the wide receptive fields of the rhabdoms will reduce its potentially high acuity. As the optical sensitivity alone cannot account for the 8 log units intensity difference between day and night, a possible role of neural summation within the first optic ganglion (lamina) of nocturnal hymenopterans is discussed. J. Comp. Neurol. 495:255–262, 2006. © 2006 Wiley‐Liss, Inc.
Novel Metallosupramolecular Networks Constructed from CuII, NiII, and CdII with Mixed Ligands: Crystal Structures, Fluorescence, and Magnetism
Authors: Du Miao , Jiang Xiu‐Juan , Zhao Xiao‐Jun , Cai Hua , Ribas Joan 
Published: January 2006

AbstractReactions of mixed ligands succinic acid (H2suc) and bent dipyridines, such as 2,5‐bis(3‐pyridyl)‐1,3,4‐oxadiazole (3‐bpo) and its 4‐N‐donor analog (4‐bpo), with inorganic CuII, NiII, and CdII salts yield three new metal‐organic coordination frameworks {[Cu(suc)(3‐bpo)(H2O)2]·(H2O)1.75}n (1), {[Ni(suc)(4‐bpo)(H2O)2]·(H2O)5}n (3), and {[Cd2(suc)2(3‐bpo)2(H2O)2]·(H2O)6.75}n (4), in which the metal centers are linked by bridging ligands 3‐bpo/4‐bpo and suc2– along two directions to form 2D infinite networks. The corrugated 2D nets of 1 and 4, obtained under hydrothermal conditions, align in an interdigitated manner with the presence of significant aromatic‐stacking interactions to result in similar 3D architectures. The 2D sheets in 3 are extended by interlayer hydrogen bonds to afford a 3D structure. However, when succinic acid is replaced by fumaric acid (H2fum) in the reaction with 3‐bpo and CuII salt, a metallacyclophane [Cu(Hfum)2(3‐bpo)(H2O)]2·(3‐bpo)2·(H2O)6 (2) is generated. The binuclear coordinated motifs are hydrogen‐bonded to the lattice water chains to furnish a unique 3D channel‐like framework, in which the guest 3‐bpo molecules are accommodated. The thermal stabilities of these new materials were investigated by thermogravimetric analysis (TGA) of mass loss. The magnetic coupling in complexes 1–3 is antiferromagnetic and very small, which is as expected considering the long organic bridges between the paramagnetic centers. The solid‐state luminescence properties of 4 reveal an intense fluorescence emission at 378 nm. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)