bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clotting Phenomena at the Blood‐Polymer Interface and Development of Blood Compatible Polymeric Surfaces
Authors: Bantjes Adriaan 
Published: April 2007

AbstractIn the past two decades many attempts have been made to relate surface and interfacial parameters with the blood compatibility of polymeric surfaces. It is however doubtful if by a single parameter the behaviour of blood on a surface can be predicted. Two major aspects of blood compatibility—the prevention of platelet adhesion and the deactivation of the intrinsic coagulation system are determined by the measure and nature of competitive blood protein adsorption on the foreign surface. The adhesion of blood platelets is promoted by adsorbed fibrinogen and gamma globulin, while adsorbed albumin inhibits platelet adhesion. Heparinised surfaces do not adsorb fibrin and consequently no adhesion of platelets takes place. Other surfaces with low platelet adhesion are the hydrogels, certain block copolyetherurethanes, polyelectrolyte complexes and biolised proteins. Heparinised surfaces of the cationically bonded type inhibit the intrinsic coagulation as well, however this may be due to unstable coatings and heparin leakage.In the authors laboratory a synthetic heparinoid was prepared with the structure ‐ [CH2 ‐ C(CH3 NHSO3 Na ‐ C(H) COONa ‐ CH2 ‐] x̄ with M̄w = (7.5 /pm 1.0) × 105 and an in vivo anticoagulant activity of 50% of heparin. Its coatings on PVC, using tridodecylmethyl‐ammonium chloride as a coupling agent, are stable in plasma and salt solutions and provide surfaces which show negligible platelet adhesion and a strong inhibition of the intrinsic coagulation on contact with blood. Similar results were found with polydimethylsiloxane surfaces coated with this heparinoid.
Crystallinity in EPDM terpolymers
Authors: Gilbert Marianne , Briggs James E. , Omana Wilberto 
Published: April 2007

AbstractThe crystallinity of a series of ‘medium‐high’ green strength EPDM terpolymers has been examined by X‐ray diffraction and thermal analysis. It has been found that the crystallinity of such materials can vary from 0.20% as measured by thermal analysis, and depends on the E:P ratio in the polymer. It is also suggested that it depends on the distribution of E and P units. An explanation for the differing results obtained by thermal analysis and X‐ray diffraction has been proposed. The time taken to achieve maximum crystallinity varied for the series of polymers examined, and the improvement of crystallites continued over extensive periods of time. The final level of crystallinity in the polymers and the rate of changes occurring was temperature dependent. For one sampel (‘Nordel’ 1560) it was shown that crystallinity affected mechanical properties.
Synthesis of some new polyers and copolymers from 2,2‐bis (4‐chlorophenyl) 1, 1, 1‐trichloro ethane (DDT)
Authors: Adam Georgius A. , Husein N. A. 
Published: April 2007

AbstractDDT (I) was polycondensed with 2,2‐bis(4‐hydroxy phenyl)‐ propane (bisphenol‐A) to form polyether. The following monomers were synthesised from DDT: 2,2‐bis(4‐chloro‐phenyl)1, 1‐dichloroethylene(II), 2,2‐bis(3‐nitro‐4‐chlorophenyl)ethane (III) and 2,2‐bis (3‐nitro‐4‐chloro‐phenylethylene (IV) and polycondensed with bisphenol‐A. They were also copolymerised with bis(4‐chlorophenyl)sulphone and bisphenol‐A in several molar ratios. The polymers and copolymers were characterised by various techniques. The results obtained show that the DDT has a low reactivity, but nitration and dehydrochlorin‐ation increases its reactivity to a significant extent.
Design of polymers for migration imaging application II: Synthesis and polymerisation of p‐isobutyl styrene
Authors: Buckley David A. , Augostini Peter P. , Belli Frank G. 
Published: April 2007

AbstractA copolymer series was synthesized for migration imaging applications from isobutyl methacrylate and isobutyl styrene such that each homopolymer and all copolymers had glass transition temperature (Tg) near 55°C. The Tg of poly (p‐isobutylstyrene) was predicted from literature values of similar polymers to be near 55°C. Poly (p‐isobutylstyrene) was synthesised by acetylation of isobutyl benzene, reduction of p‐isobutylacetoph‐enone to the carbinol, dehydration to p‐isobutylstyrene and free radical polymerisation to the polymer. The Tg of the homopolymer was 55°C, in excellent agreement with the predicted value. Copolymers of isobutyl methacrylate and p‐isobutyl styrene were synthesised and their Tg's measured across the series by DSC (57°C ± 5°C). refractive index temperature coefficient (42°C ± 5°C). The copolymer series was also characterised by melt viscosity measurements.
Mineral sources of polyorganosiloxane materials
Authors: Atwal Rajinder S. , Bicknell Stanley , Cook Colin B. , Currell Brian R. , Midgley Henry G. , Mooney Anthony J. , Parsonage John R. 
Published: April 2007

AbstractThe trimethylsilylation of biotite and phlogopite gives good yields of polyorganosiloxanes. Al3+ ions have an important influence on the fragmentation of the mineral structure into silicate anions prior to trimethylsilylation.The authors have shown by using wet analytical techniques as well as X‐ray diffraction and electron probe microanalysis that biotite and phlogopite retain aluminium in preference to magnesium during the course of extensive trimethylsilylation reactions. The labile nature of the >Al‐O‐Si<‐ bonds, and the size of the AI3+ ion which allows exchange between the octahedral and tetrahedral mineral sites, contribute to the good yields of polyorganosiloxanes which can be produced by this method. The mechanism for the reaction is presented. Yields may be increased by decreasing the particle size of the mineral and also by removing polyorganosiloxanes from the mineral surface.
The mechanical properties of some filled polymer cements
Authors: Carrillo Jorge , Hodd K A 
Published: April 2007

AbstractThe tensile and compressive strengths and the elastic moduli of sand and asbestos filled polymer cements, based on the aluminosilicate/poly(acrylic acid) (ASPA) system, have been measured. A progressive decline in property with increasing volume fraction of filler (in the range 5 to 12%) was observed. The decline is interpreted in terms of dilution, lack of matrix‐filler interaction and void content.
The hydration of a glass‐ionomer (ASPA) cement
Authors: Wilson Alan D. , Crisp Stephen , Paddon John M. 
Published: April 2007

AbstractThe hydration of chemical species formed in the cement‐forming reaction has been studied by measuring the evaporable, and non‐evaporable water contents of a glassionomer cement at various stages in its history. Hydration is accompanied by increase in strength and, as loose water is removed from the matrix, a decrease in plasticity. Hydration is attributed to ionisation of the polymeric carboxylic acid and transfer of metal ions from the glass to the polyelectrolyte.
Applications of Xanthan gum
Authors: Sanderson George R. 
Published: April 2007

AbstractXanthan gum, the extracellular polysaccharide from Xanthomonas comperstris, provides aqueous solutions with properties that are extremely useful in a large number of industrial applications, both food and non‐food. These properties, a consequence of xanthan gum's particular molecular shape, are: high at‐rest or low‐shear viscosity even at low gum concentrations, yield value, high pseudoplasticity, increased viscosity in the presence of added salt depending on gum concentration, stable viscosity over a wide range of temperature and pH in the presence of added salt, synergistic increase in viscosity in the presence of guar gum and locust bean gum, thermoreversible gelation with locust bean gum at appropriate gum concentratins, and gelation with di‐and trivalent metal ions and borates under specific conditions. Xanthan gum is thus an excellent stabiliser for a wide variety of suspensions, emulsions, and foams and is highly effective over a range of temperature, pH and ionic strength. In addition, its pseudoplasticity allows the formulation of products which require not only high at‐rest viscosity but also low viscosity under highshear application conditions.
A microfiltration technique for cleaning polymer latices
Authors: Wilkinson M. C. , Hearn J. , Cope P. , Chainey M. 
Published: April 2007

AbstractA microfiltration technique for cleaning polymer latices is evaluated. The modified millipore microfiltration cell employed is described and optimum operating conditions given: the cell consists of a 47 mm diameter millipore filter supported on a stainless steel mesh and contained within a PTFE body. Double distilled water is pumped through the cell, removing impurities from the latex. The latex particles are retained by the filter: pore blockage is prevented by PTFE coated magnetic stirrer bar. The nature and location (water or polymer phases) of the major impurities encountered with polystyrene latices are identified. The efficiency with which microfiltration removes these impurities is compared with dialysis and ion exchange. Monomer, low molecular weight oligomer, benzaldehyde, and surface active agent are completely removed. However, electrolytic material associated with the polymer phase is not completely removed by this technique. Microfiltration may also be used to concentrate a latex and separate latex particles of different sizes.
Radiation induced ionic polymerisation and grafting of vinyl monomers
Authors: Stannett Vivian T. 
Published: April 2007

AbstractSome special aspects of the radiation induced ionic polymerisation and grafting of vinyl monomers will be described. In particular the effects of solvents on the cationic polymerisation of the vinyl ethers will be discussed in detail. The unequivocal free ion nature of the polymerisation makes such information of considerable general interest. Estimates of the propagation rate constants with free cation polymerisation in solvents of different dietectric constants and solvation powers will be presented. Finally, some observations on the radiation induced graft polymerisation of ethyl vinyl ether to poly (vinyl chloride) and to polypropylene will be presented.
Use of functionalised silica in catalysis and organic synthesis
Authors: Akelah Ahmed 
Published: April 2007

AbstractUses of silica in the immobilisation of enzymes and functionalized reagents for resolution of racemic mixtures and synthesis of peptides, oligonucleotide and other compounds are discussed. Silica is superior over organic polymers in its high chemical stability, and being virtually nonswellable. This inhibits the influence of the solvent on physical and chemical behaviour of attached moeties and permits automisation of batch processes.
Preparation of polyphosphonates
Authors: Currell Brian R. , Grzeskowiak Roman , Lynn Michael E. 
Published: April 2007

AbstractPolyphenylphosphonates have been prepared by (i) the elimination of hydrogen chloride from mixtures of PhPOCl2 and PhPO(OH)2, (ii) the elimination of methyl chloride from PhPOCl2 and PhPO(OMe)2, and (iii) the elimation of methanol from PhPO(OMe)2 and PhPO(OH)2. Products have been characterised by elemental analyses, gel permeation chromatography, molecular weight measurement and infrared spectroscopy. In each case mixtures of rings and chains were obtained. Polyphosphonates were also obtained by the elimination of hydrogen chloride from mixtures of MePOCl2 and MePO(OH)2 and from mixtures of PhOCl2 and MePO(OH)2.
Preparations and properties of phenanthrene ‐ formaldehyde resins
Authors: Herbert Lesley D. , Robinson J. Gordon , Marr George 
Published: April 2007

AbstractPhenanthrene was treated with formaldehyde in the presence of sulphuric acid and the yields of resin obtained were dependent on the acid concentration and on the molar ration of formaldehyde to phenanthrene. All of the resins were composed of dimers, trimers, tetramers and higher oligomers. The bridges joining the phenanthryl units were mainly methylene when formaldehyde was in molar deficit relative to phenathrene, but dimethylene ether and acetal bridges were present when the formaldehyde was in molar excess.
[5‐(p‐alkoxy)phenyl‐10, 15, 20‐tri‐phenyl] porphyrin and their rare earth complex liquid crystalline
Authors: Yu Miao , Zhang Wen‐yang , Fan Yong , Jian Wen‐ping , Liu Guo‐fa 
Published: April 2007

AbstractThree series of porphyrin liquid crystalline compounds, [5‐(p‐alkoxy)phenyl‐10, 15, 20‐tri‐phenyl] porphyrin and their rare earth complexes (Tb (III), Dy (III), Er (III), Yb (III)), with a hexagonal columnar discotic columnar(Colh) phase have been synthesized. These compounds were characterized by elemental analysis, molar conductances, UV‐visible spectra, infrared spectra, luminescence spectra, and cyclic voltammetry. These compounds exhibit more than one mesophases, which transition points of temperature change from −33.6 to 16.0 °C, and transition points of temperature for isotropic liquid also increase from 4.9 to 38.2 °C, with increasing chain length. Their surface photovoltage (SPV) response have also been investigated by the means of surface photovoltage spectroscopy (SPS) and field‐induced surface photovoltage spectroscopy (EFISPS). It was found that their SPV bands are analogous with the UV‐visible absorption spectra and derived from the same transition. Copyright © 2007 John Wiley & Sons, Ltd.
Structural and electrical properties of crystals of substituted polyaniline
Authors: Seshadri Devender T. , Bhat Narendra V. 
Published: April 2007

AbstractThe simultaneous polymerization and crystallization of aniline has been reported earlier. In this article, the X‐ray crystal structure analysis, SEM morphological analysis and electrical properties of such crystals of oligo‐polyanilines are being reported. The structural analysis shows a pseudo‐orthorhombic lattice. The SEM images reveal flaky and triangular growth habit with granular overgrowths on the surface. The bulk conductivities achieved vary from 10−5 S/cm to 10−7 S/cm as the oxidant concentration is reduced from 5 to 0.1%. The temperature dependence showed a transition point upto which there is a decrease in current and above which the current increases. The ESR studies reveal polarons involved in charge conduction and their concentration is proportional to the oxidant concentration. The X‐ray patterns, conductivities, and ESR results have been correlated with the degree of polymerization results obtained from GPC studies. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1127–1137, 2007
Preparation and properties of ZnO and devices
Authors: Izyumskaya N. , Avrutin V. , Özgür Ü. , Alivov Y. I. , Morkoç H. 
Published: April 2007

AbstractZnO has gained interest in part because of its large exciton binding energy (60 meV), good for lasing with low threshold. The renewed interest in ZnO is fuelled by availability of high quality substrates, reports of p‐type conductivity, and ferromagnetic behavior when doped with transitions metals. The field is also fuelled by theoretical predictions and perhaps experimental confirmation of ferromagnetism at room temperature for potential spintronics applications. Despite great strides there are still many challenges, the chief among them is the attainment of reproducibly low resistivity p‐type ZnO. While ZnO already has many industrial applications owing to its piezoelectric properties and bandgap in the near UV, its applications to optoelectronic devices utilizing electrical injection has not yet been put to practice mainly due to the lack of p‐type epitaxial layers. This review provides a discussion of some of the growth issues of ZnO‐based epitaxial and heteroepitaxial layers and their use in a variety of devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cathodoluminescence of single ZnO nanorod heterostructures
Authors: Piechal Bernard , Yoo Jinkyoung , Elshaer Abdelhamid , Mofor Augustine Che , Yi Gyu‐Chul , Bakin Andrey , Waag Andreas , Donatini Fabrice , Dang Le Si 
Published: April 2007

AbstractOptical properties of ZnO‐based single nanorods are probed by cathodoluminescence (CL) measurements at T = 5 K. We observe a variation of the ZnO near band edge CL by three orders of magnitude along the nanorod axis, accompanied by a spectral blueshift of 10–30 meV. This indicates a rather poor structural quality of the nanorod bottom part, close to the substrate. ZnO/ZnMgO quantum wells grown on top of ZnO nanorods are found to exhibit much stronger confinement effects as compared to their two‐dimensional counterparts, suggesting a reduced spontaneous and piezoelectric polarization effects. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Gas family of proteins of Saccharomyces cerevisiae: characterization and evolutionary analysis
Authors: Ragni Enrico , Fontaine Thierry , Gissi Carmela , Latgè Jean Paul , Popolo Laura 
Published: April 2007

AbstractThe GAS multigene family of Saccharomyces cerevisiae is constituted by five genes (GAS1–GAS5), but GAS1 was the only one to have been characterized to date. Gas1 is a glycosylphosphatidylinositol‐anchored protein predominantly localized in the plasma membrane and is also a representative of family GH72 of glycosidase/transglycosidases, a wide group of yeast and fungal enzymes involved in cell wall assembly. Gas1–Gas5 proteins share a common N‐terminal domain but exhibit different C‐terminal extensions, in which a domain named Cys‐Box is located. This domain is similar to the carbohydrate binding module 43 and is present only in Gas1p and Gas2p. Here we report the expression in P. pastoris of soluble forms of Gas proteins. Gas1, 2, 4 and 5 proteins were secreted with a yield of about 30‐40 mg/l of medium, whereas the yield for Gas3p was about three times lower. Gas proteins proved to be N‐glycosylated. Purified Gas proteins were tested for enzymatic activity. Gas2, Gas4 and Gas5p showed a β‐(1,3)‐glucanosyltransferase activity similar to Gas1p. A phylogenetic tree of the N‐terminal regions of family GH72 members was constructed. Two subfamilies of N‐terminal regions were distinguished: one subfamily, GH72+, contains proteins that possess a Cys‐box in the C‐terminal region, whereas family GH72− comprises proteins that lack a Cys‐box. On the basis of this net distinction, we speculate that the type of C‐tail region imposed constraints to the evolution of the N‐terminal portion. Copyright © 2007 John Wiley & Sons, Ltd.
Dissecting the transcriptional activation function of the cell wall integrity MAP kinase
Authors: Kim Ki‐Young , Cosano Inmaculada C. , Levin David E. , Molina María , Martín Humberto 
Published: April 2007

AbstractThe cell wall integrity signalling MAP kinase of Saccharomyces cerevisiae, Slt2p/ Mpk1p, is activated in response to cell wall stress. Slt2 and its mammalian orthologue ERK5 are unusual among MAP kinases, in that they possess the ability to activate transcription of a GAL1‐lacZ reporter when fused to the DNA‐binding domain of the Gal4 transcription factor. In this study, we demonstrate that transcriptional activation of a Gal4–Slt2p fusion is responsive to cell wall stress and requires phosphorylation of Slt2p. We identify two neighbouring but separable transcription activation domains within the C‐terminal half of Slt2p. Additionally, we present data suggesting that intramolecular interactions controlled by phosphorylation of Slt2p regulate the function of these domains, which are masked by the N‐terminal catalytic domain under inactive conditions. Finally, we demonstrate that Slt2p self‐associates, probably through a glutamine‐rich region within the C‐terminal half of the protein. Copyright © 2007 John Wiley & Sons, Ltd.
Extraction of cell surface‐associated proteins from living yeast cells
Authors: Klis Frans M. , de Jong Marian , Brul Stanley , de Groot Piet W. J. 
Published: April 2007

AbstractTo extract cell surface‐associated proteins from living fungal cells, reducing agents such as β‐mercaptoethanol and dithiothreitol are often used. We show here that both compounds are moderately lipophilic and may perturb the plasma membrane, thus causing the release of cytosolic proteins, especially at high extraction temperatures. To avoid artifacts, we recommend using (a) a low concentration of the reducing agent for only a short period of time, and (b) an extraction temperature of 4 °C to protect the integrity of the plasma membrane. Similarly, biotinylation of cell surface proteins should be carried out at low temperatures in the absence of dimethylsulphoxide. Copyright © 2007 John Wiley & Sons, Ltd.
An electron microscope study of certain dispersions of detergents in oil
Authors: Peri J. B. 
Published: April 2007

Summary1. Electron micrographs of certain detergent and soap micelles presumably existing in oil solution are presented.2. Both “spherical” and rodlike micelles appear to exist in oil. These micelles are apparently two molecular lengths in diameter. The rodlike micelles are of variable length, ranging up to over 300 Å. It seems likely that in some instances these rods are small linear aggregates of “spherical” micelles.3. Association of rodlike micelles to form paracrystalline sheaves of long fibers is indicated. These structures apparently maintain fairly uniform spacings of from 80 Å to 100 Å between centers of the rods or fibers although the micelles appear to be only about 50 Å in diameter.4. Aggregation of spherical micelles to form small colloid crystalline regions in large agglomerates is demonstrated.
Degradation of longicorn beetle (Coleoptera, Cerambycidae, Disteniidae) fauna caused by conversion from broad‐leaved to man‐made conifer stands of Cryptomeria japonica (Taxodiaceae) in central Japan
Authors: Makino Shun'ichi , Goto Hideaki , Hasegawa Motohiro , Okabe Kimiko , Tanaka Hiroshi , Inoue Takenari , Okochi Isamu 
Published: April 2007

AbstractWe studied the species richness and assemblages of longicorn beetles (Coleoptera, Cerambycidae, Disteniidae) in ten secondary broad‐leaved stands and eight plantation stands of Japanese cedar (Cryptomeria japonica) of various ages after clear‐cutting or plantation in Ibaraki, central Japan. The species richness of longicorns, which were collected with Malaise traps, was the highest in young stands, decreasing with the age of the stand for both broad‐leaved and conifer stands. A canonical correspondence analysis divided the 18 plots into three groups based on longicorn assemblages and environmental variables. These three groups consisted of (1) very young (1–4 years old) stands after clear‐cutting or plantation; (2) 12‐ to over 100 year‐old broad‐leaved stands; (3) 7‐ to 76‐year‐old conifer stands. The species richness of the longicorns was the highest in the young stands followed, in order of decreasing species richness, by broad‐leaved stands and conifer stands. Possible causes of the high species richness in young stands include large amounts of coarse wood debris and flowers, which are resources for oviposition and nutrition for adults, respectively. The lower longicorn diversity in conifer stands than in broad‐leaved stands may be due to the lower diversity of trees available as host plants in the former. Almost all species that occurred in conifer stands were also collected in young and/or broad‐leaved stands, but the reverse was not true, suggesting that conifer plantations cannot replace broad‐leaved stands in terms of longicorn biodiversity. We argue that an extensive conversion of broad‐leaved forests into conifer plantations will lead to an impoverishment of the longicorn fauna, which may result in the degradation of ecosystem functions possibly carried out by them.