bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on effective storage time of raw natural rubber
Authors: Zhang Bei‐Long , Deng Wei‐Yong , Lu Heng‐Xiang , Chen Mei , Qian Hong‐Lian 
Published: March 2006

AbstractThe effective storage time (i.e., storage life) of raw natural rubber (NR) was investigated with heat‐accelerated storage aging combined with thermogravimetry (TG) and differential thermal analysis (DTA) method, as well as the heat aging life equation. The test results show that the effective storage time of raw NR can be estimated more conveniently in relatively shorter time by this method. It is found that the effective storage time of raw NR is associated with rubber processing technology and with ambient temperature during storage, but it has little relation with P0 and PRI. At ambient temperature, the effective storage time of the natural‐coagulated and biological‐coagulated NR is obviously higher than the acetic acid‐coagulated NR; the lower the ambient temperature, the longer the effective storage time. The effective storage time of the acetic acid‐coagulated NR is 12.2–13.4 years at ambient temperature of 30°C, 23.8–25 years at 25°C, and 47.4–47.9 years at 20°C. The effective storage time of the natural‐ and biological‐coagulated NR is 13.7–15.2 years at 30°C, 29.6–30.4 years at 25°C, and about 62.5–65.8 years at 20°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4114–4119, 2006
Magnetic composites obtainment based on styrene polymers
Authors: Nita Loredana Elena , Chiriac Aurica P. , Neamtu Iordana , Vasile Cornelia 
Published: March 2006

AbstractThree styrene‐based matrices for hybrid composites with ferrite have been obtained by emulsion polymerization in the presence of a tensioactive system: sodium n‐dodecylbenzene sulfate (C12H25C6H4SO3Na) as anionic agent and poly(oxyethylene) nonylphenyl ether [C9H19C6H4(OCH2CH2)30OH] as nonionic tensioactive agent. The system assures the steadiness of the emulsion during the reaction and the stability of the latices. The surfactants act as a protective colloid component and thickening agents determining an optimum viscosity and conditions for the further catching of the inorganic oxide with magnetic properties. The obtained polystyrene and styrene copolymers with acrylamide and methacrylamide were analyzed by elemental analysis, IR spectroscopy, DSC, and their viscosity data have been characterized. The size as well as the magnetic properties of composites were also appreciated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4133–4141, 2006
Effect of γ‐aminopropyl trimethoxy silane on the performance of jute–polycarbonate composites
Authors: Khan Mubarak A. , Hassan M. Masudul 
Published: March 2006

AbstractThe composites of jute fabrics (hessian cloth) and polycarbonate were prepared by compression molding. The jute surface was modified with γ‐aminopropyl trimethoxy silane (Z‐6011) to improve interfacial adhesion between jute and polycarbonate. The treated and untreated jute surfaces as well as composites were investigated by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Environmental scanning electron microscopy, Dynamic mechanical analysis, and mechanical testing. XPS and FTIR assure that the silane plays important role to form interfacial bonding with the jute fibers and polycarbonate. The surface topography of silanized and virgin fibers, and the interfacial adhesion properties of the composite were investigated by ESEM. DMA analysis shows the improved storage and loss moduli of silanized jute composite as compared to the untreated one. The modified jute composite also produces enhanced mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4142–4154, 2006
Thermal and mechanical properties of polypropylene–wood powder composites
Authors: Salemane M. G. , Luyt A. S. 
Published: March 2006

AbstractThe preparation and characterization of modified and unmodified polypropylene (PP)–wood powder (WP) composites were done under fixed processing conditions. Different techniques were used to study the effect of both WP size and content, as well as compatibilizer content, on the properties of the composites. The results point to the fact that, WP settles in the amorphous part of the matrix and creates new crystalline phases or zones. Scanning electron microscopy micrographs show a relatively even distribution of WP in the PP matrix, which contributes to improvements observed in the properties of the material. Hg‐porosimetry results indicate that the PP matrix, which has a low pore volume, filled the pores in the WP particles. This reduced the total volume of pores in the PP–WP composites. This observation was also supported by a general decrease in gas permeability of the material. Thermal analysis results indicate that the presence of both WP and maleic anhydride grafted polypropylene (MAPP) leads to an increase in enthalpy (crystallinity) values, but to a decrease in lamellar thickness in the composites. The thermal stability of the composites improves somewhat compared to that of PP. There were distinctive differences between the results for composites containing different WP particle sizes, as well as for composites prepared in the presence and absence of MAPP. It is clear from the results that the presence of MAPP generally improves the tensile properties of the composites. Larger WP particles gave rise to better tensile properties, in the presence and absence of MAPP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4173–4180, 2006
Dyeing mechanism and model of nylon 6 fiber dyeing in low‐temperature hydrogen peroxide–glyoxal redox system
Authors: Wang Huei‐Hsiung , Wang Chyung‐Chyung 
Published: March 2006

AbstractThis article reports the results of a study of nylon 6 fiber dyed in a low‐temperature hydrogen peroxide–glyoxal redox system. It was expected that the dyed fiber would have better dye fastness and higher economic value than would conventional fiber. In addition, this article presents the proposed mechanism for and model of a free‐radical dyeing system as well as a derived theoretical equation. From the experimental results, it was found that formation of covalent bonds by the coupling of the dye and the fiber radical in free‐radical dyeing was only 25%–40%, whereas with the conventional type of ionic dyeing, it was almost 60%–75%. Because the initiation efficiency of free‐radical formation is affected by many factors, such as the pH of the dye bath and the concentrations of the oxidant and reductant, the aims of this study were to investigate the formation of free radicals and the effects on dye uptake of the concentrations of dye, oxidant, and reductant and of the fiber amine end group. In addition, the dyeing properties of dyed fiber were investigated, and the dyeing order and rate constant of the rate equation were evaluated from the experimental data. From the experimental results, the following conclusions were drawn. (1) The hydrogen peroxide–glyoxal redox system produced many free radicals in the dye bath as temperature reached 70°C. (2) The amine end group in the nylon fiber was the main site of ionic and covalent bonding between nylon 6 fiber and dye. (3) The proposed model of free‐radical dyeing showed, from the fit of the experimental data into the equation and the evaluation of the equation parameters, that the order fit the theoretical value well, with the rate constant dependent on the dyeing conditions; at pH = 3, it could match the equation's best (rate equation of the proposed model: d[D]R/dt = kA[GO]1[H2O]m[D]1/2[F]1/2). (4) The optimum dyeing conditions in the hydrogen peroxide–glyoxal redox system were: [H2O2] = 0.15–0.20M, [glyoxal] = 0.07–0.10M, pH = 3, dyeing temperature = 70°C, and dyeing time = 45–50 min. (5) The redox dyeing system had better dye fastness than did the conventional system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4197–4207, 2006
Physical chemistry of topological disorder in polymers: Some remarks on polymer memory
Authors: Shlyapnikov Y. A. , Kolesnikova N. N. 
Published: March 2006

AbstractThe long‐term structural memory of a polymeric substance is determined by the concentration, size, and space distribution of the elements of topological disorder present in it. The short‐term structural memory is the result of the reversible reconstruction of existing elements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:4208–4211, 2006
Study on the prediction technique of the wear amount of polyoxymethylene
Authors: Kada Masahiro , Ishikawa Masaru 
Published: March 2006

AbstractThe influence of the sliding velocity and atmospheric temperature on the specific wear amount of polyoxymethylene was evaluated with the ring‐on‐ring apparatus. The specific wear amount showed the variation of S‐character type with maximum value, according to the change in the sliding velocity and the atmospheric temperature. When those results are plotted according to the sliding surface temperature, they have been found to be arranged as the same dependence. The specific wear amount of polyoxymethylene was assumed to be proportional to the product of actual contact area and reciprocal of the fracture energy. Then, the temperature dependency of the product of the fracture energy, calculated from stress–strain curve, and the actual contact area, calculated from Hertz's equation with elastic modulus, was able to explain the sliding surface temperature dependency of the specific wear amount well. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4212–4218, 2006
Hydrogenation of synthetic cis‐1,4‐polyisoprene and natural rubber catalyzed by [Ir(COD)py(PCy3)]PF6
Authors: Hinchiranan Napida , Charmondusit Kitikorn , Prasassarakich Pattarapan , Rempel Garry L. 
Published: March 2006

AbstractIn the presence of chlorinated solvents, the catalytic complex [Ir(COD)py(PCy3)]PF6 (where COD is 1,5‐cyclooctadiene and py is pyridine) was an active catalyst for the hydrogenation of synthetic cis‐1,4‐polyisoprene and natural rubber. Detailed kinetic and mechanistic studies for homogeneous hydrogenation were carried out through the monitoring of the amount of hydrogen consumed during the reaction. The final degree of olefin conversion, measured with a computer‐controlled gas‐uptake apparatus, was confirmed by Fourier transform infrared spectroscopy and 1H‐NMR spectroscopy. Synthetic cis‐1,4‐polyisoprene was used as a model polymer for natural rubber without impurities to study the influence of the catalyst loading, polymer concentration, hydrogen pressure, and reaction temperature with a statistical design framework. The kinetic results for the hydrogenation of both synthetic cis‐1,4‐polyisoprene and natural rubber indicated that the hydrogenation rate exhibited a first‐order dependence on the catalyst concentration and hydrogen pressure. Because of impurities inside the natural rubber, the hydrogenation of natural rubber showed an inverse behavior dependence on the rubber concentration, whereas the hydrogenation rate of synthetic rubber, that is, cis‐1,4‐polyisoprene, remained constant when the rubber concentration increased. The hydrogenation rate was also dependent on the reaction temperature. The apparent activation energies for the hydrogenation of synthetic cis‐1,4‐polyisoprene and natural rubber were evaluated to be 79.8 and 75.6 kJ/mol, respectively. The mechanistic aspects of these catalytic processes were discussed on the basis of observed kinetic results. The addition of some acids showed an effect on the hydrogenation rate of both rubbers. The thermal properties of hydrogenated rubber samples were determined and indicated that hydrogenation increased the thermal stability of the hydrogenated rubber but did not affect the inherent glass‐transition temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4219–4233, 2006
Preparation and characterization of Bombyx mori silk fibroin and wool keratin
Authors: Iridag Yesim , Kazanci Murat 
Published: March 2006

AbstractSilk and wool are well‐known protein‐based fibers. Their environmental stability, biocompatibility, and unique mechanical properties provide an important basis for using these natural proteins in biomedical applications. To use them as biomaterials in the form of fibers, films, or membranes, it is necessary to characterize these proteins in their solution and solid states because structural characteristics and morphological features have a great influence on the physical and mechanical properties of these new regenerated protein forms. Therefore, in the present study, silk fibroin and wool keratin were dissolved and their solution behaviors and secondary structures are analyzed and compared, using particle size distribution, molecular weight distribution (SDS‐PAGE), Fourier transform infrared, and X‐ray diffraction techniques. It was shown that keratin is more stable in solution and more amorphous in the solid state. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:4260–4264, 2006
Graft copolymerization of styrene onto casein initiated by potassium diperiodatonickelate (IV) in alkaline medium
Authors: Weiqi Zhou Yinghai Liu , Bai Libin , Zhao Na , Liu Yuanwei 
Published: March 2006

AbstractA novel redox system, potassium diperiodatonickelate (Ni(IV))‐casein is used to initiate graft copolymerization of Styrene onto casein under different conditions in aqueous alkaline solution. Graft copolymers with both high grafting efficiency (>98%) and percentage of grafting(>300%) are obtained, which indicated that (Ni(IV))‐casein redox pair is an efficient initiator for this grafting. The effects of reaction parameters, such as monomer‐to‐casein weight ratio, initiator concentration, pH, time, and temperature, are investigated. A tentative initiation mechanism is proposed. The structures and properties of the graft copolymer are characterized by Fourier transform infrared Spectroscopy, X‐ray diffraction diagrams, and Scanning Electron Microscope. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4247–4251, 2006
In Vitro metabolism of ciclesonide in human lung and liver precision‐cut tissue slices
Authors: Nave Ruediger , Fisher Robyn , Zech Karl 
Published: March 2006

AbstractCiclesonide is a new‐generation inhaled corticosteroid developed to treat the inflammation associated with persistent asthma. In order to identify the properties of ciclesonide responsible for anti‐inflammatory activity, ciclesonide metabolism was investigated in human lung and liver precision‐cut tissue slices. Three human lung and three human liver tissue slices were incubated with 25 µM [14C]‐ciclesonide for 2, 6 and 24 h. Cellular viability was assessed using adenosine 5′‐triphosphate content and protein synthesis in lung slices and adenosine 5′‐triphosphate content and potassium retention in liver slices. Ciclesonide and ciclesonide metabolites were analysed in tissue samples using high‐performance liquid chromatography with ultraviolet and radiochemical detection. Metabolite identity was confirmed using mass spectrometry. In lung slices, the inactive parent compound, ciclesonide, was initially converted to the active metabolite, desisobutyryl‐ciclesonide, and subsequently converted to fatty acid conjugates. The reversible formation of fatty acid conjugates was a major pathway of ciclesonide metabolism in human lung slices. The primary conjugate was identified as desisobutyryl‐ciclesonide oleate. Ciclesonide was metabolized to at least five polar metabolites in the liver. Dihydroxylated desisobutyryl‐ciclesonide was the major polar metabolite in liver slices. Activation and fatty acid esterification in the lung followed by rapid inactivation in the liver may explain the improved safety profile and prolonged anti‐inflammatory activity of ciclesonide. Copyright © 2006 John Wiley & Sons, Ltd.
Assessing the Amount of Heterogeneity in Random‐Effects Meta‐Analysis
Authors: Knapp Guido , Biggerstaff Brad J. , Hartung Joachim 
Published: March 2006

AbstractIn a random‐effects meta‐analysis, a new confidence interval for the heterogeneity parameter is proposed. With this interval, the amount of heterogeneity in a meta‐analysis can be assessed so that it can be judged whether the pooling of the estimates is meaningful. Through suitable corrections of the lower bound, based on the treatment effect measure of interest, the resulting interval yields satisfactory results with respect to the predefined confidence coefficient. Lower and upper bound of the interval can be used for one‐sided hypothesis testing on the amount of the underlying between‐trial variability. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Renewed Approach to the Nonparametric Analysis of Replicated Microarray Experiments
Authors: Jung Klaus , Quast Karsten , Gannoun Ali , Urfer Wolfgang 
Published: March 2006

AbstractDNA‐microarrays find broad employment in biochemical research. This technology allows the monitoring of the expression levels of thousands of genes at the same time. Often, the goal of a microarray study is to find differentially expressed genes in two different types of tissue, for example normal and cancerous. Multiple hypothesis testing is a useful statistical tool for such studies. One approach using multiple hypothesis testing is nonparametric analysis for replicated microarray experiments. In this paper we present an improved version of this method. We also show how p ‐values are calculated for all significant genes detected with this testing procedure. All algorithms were implemented in an R‐package, and instructions on it's use are included. The package can be downloaded at http://www.statistik.uni‐dortmund.de/de/content/einrichtungen/lehrstuehle/personen/jung.html
Parameters affecting the adsorption of plantaricin 423, a bacteriocin produced by Lactobacillus plantarum 423 isolated from sorghum beer
Authors: Todorov Svetoslav D. , Dicks Leon M. T. 
Published: March 2006

AbstractPlantaricin 423 is bactericidal to logarithmic and stationary‐phase cells of Enterococcus sp. HKLHS and L. sakei DSM 20017. Detection of extracellular DNA and β‐galactosidase suggests that the mode of action is most probably by destabilizing of the cell membrane. Adsorption of plantaricin 423 to target cells ranged from 17% for Streptococcus caprinus ATCC 700066 to 67% for Lactobacillus plantarum LMG 13556, Lactobacillus curvatus DF38, Listeria innocua LMG 13568 and Lactobacillus sakei DSM 20017. Treatment of Enterococcus sp. HKLHS and L. sakei DSM 20017 with Triton X‐100, Triton X‐114 and chloroform increased the adsorption of plantaricin.
Marine glycosyl hydrolases in the hydrolysis and synthesis of oligosaccharides
Authors: Giordano Assunta , Andreotti Giuseppina , Tramice Annabella , Trincone Antonio 
Published: March 2006

AbstractThe marine ecosystem can be considered a rather unexplored source of biological material (e.g. natural substances with therapeutic activity) and can also be a surprising source of enzymes carrying new and interesting catalytic activities to be applied in biocatalysis. The use of glycosyl hydrolases from marine environments dates back to the end of the 1960s and was mainly focused on the development of sensitive and reliable hydrolytic methods for the analysis of sugar chains. As a result not all the benefits of a particular enzymatic activity have been investigated, especially regarding the transglycosylation potential of these enzymes for the synthesis of glycosidic bonds. In this review, the potential of marine sources will be demonstrated reporting on the few examples found in literature for the synthesis and hydrolysis of biologically relevant oligosaccharides catalyzed by glycosyl hydrolases of marine origin. Particular emphasis is given to the synthesis of glycosidic bonds, which is easy by the use of glycosyl hydrolases. Further aspects considered in this review are applications of these biocatalysts for vegetal waste treatment in recovering useful materials, for structural identification and for preparation of target materials from new purified polysaccharides, for the synthesis or modification of food‐related compounds and for glycobiology related studies.
Human and bovine lactoferrins in the milk of recombinant human lactoferrin‐transgenic dairy cows during lactation
Authors: Hyvönen Paula , Suojala Leena , Haaranen Johanna , von Wright Atte , Pyörälä Satu 
Published: March 2006

AbstractSeven Friesian human lactoferrin (hLf)‐transgenic primiparous dairy cows expressing recombinant hLf (rhLf) in their milk were included in the study. After calving, concentrations of rhLf and bovine LF (bLf) in the milk, somatic cell count and milk yield were determined. The concentration of rhLf was found to be constant, about 2.9 mg/mL, throughout the early lactation period of 3 months. The concentration of bLf in colostrum was higher after calving, but decreased rapidly during the first days of lactation. The mean concentration of bLf was 0.15 mg/mL, but concentrations varied between cows from 0.07 mg/mL to 0.26 mg/mL. Based on that, it may be possible to improve the non‐specific host defence mechanism in the mammary gland of dairy cows by enhancing the content of rhLf in the milk.
CO2‐Minderung in der chemischen Industrie
Authors: Leimkühler H‐J. , Helbig A. 
Published: March 2006

AbstractMit dem Start des europäischen CO2‐Zertifikatehandels am 1. Januar 2005 wurden erstmalig Treibhausgasemissionen direkt Kosten zugewiesen. Dieser Mechanismus ist jedoch nur einer von vielfältigen Anreizen zur Minderung von Treibhausgasemissionen in der Industrie. Im Rahmen der Responsible Care‐Initiative hat sich die chemische Industrie bereits seit langem verpflichtet, aktiv ihren Beitrag zum weltweiten Klimaschutz zu leisten. Dieser Beitrag gibt einen Überblick über die aktuellen energiepolitischen und wirtschaftlichen Rahmenbedingungen für die Durchführung von CO2‐Minderungsmaßnahmen in der chemischen Industrie. Der zur Verfügung stehende Maßnahmenkatalog umfasst Verbesserungen der Energieumwandlung, Verfahrensverbesserungen, Standort‐Optimierungen und „End of Pipe”︁‐Technologien. Die einzelnen Maßnahmen werden anhand von Fallbeispielen erläutert.
Automatisierte RNA‐Aufreinigung aus Escherichia coli zur Standardisierung von Microarray‐Experimenten
Authors: Buchholz S. , Stahl F. , Scheper T. 
Published: March 2006

AbstractMit Hilfe moderner Biochips, mit denen man die Aktivität tausender Gene gleichzeitig untersuchen kann, sind heute Untersuchungen zur Genexpression und Mutationsdiagnostik in bis vor kurzem nicht vorstellbarem Umfang möglich. Im Gegensatz zu den High‐Throughput‐Chipsystemen ist die zugehörige Nasschemie wie die RNA‐Aufreinigung und cDNA‐Synthese manuell zeitaufwändig durchzuführen, wodurch sich bezüglich Präzision und Reproduzierbarkeit Nachteile ergeben. Daher sind moderne Liquid Handling Tools unentbehrlich.
Bionik im Reagenzglas – Biokatalysator‐Design nach dem Vorbild der Natur durch gerichtete Evolution
Authors: Eggert T. 
Published: March 2006

AbstractUnter dem Begriff Bionik werden technische Anwendungsprinzipien zusammengefasst, die aus der Natur abgeleitet wurden. Hierzu zählen Entwicklungen wie beispielsweise die Winglets an den Spitzen von Flugzeugflügeln zur Senkung des Treibstoffverbrauchs oder der allseits beliebte Klettverschluss an Taschen oder Kleidungsstücken. Auch in der Biotechnologie kann man sich heute biomimetische Verfahren nicht mehr wegdenken. So werden in der Biokatalysator‐Entwicklung ebenfalls aus der Natur abgeleitete Techniken eingesetzt, die als gerichtete Evolution bezeichnet werden.
Weiße Biotechnologie bei Bayer HealthCare Product Supply: Mehr als 30 Jahre Erfahrung
Authors: Schedel M. 
Published: March 2006

AbstractWichtige Projekte der Weißen Biotechnologie, die derzeit bei Bayer HealthCare Product Supply bearbeitet werden, reichen von der Fermentation von Sekundärstoffen über die Herstellung und den Einsatz von Ganzzell‐Biokatalysatoren im Technikums‐ und Produktionsmaßstab bis zur Entwicklung und technischen Nutzung leistungsfähiger rekombinanter Expressionssysteme zur Gewinnung von Proteinwirkstoffen.