bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic blends of natural polymers, pectin and sodium alginate
Authors: Gohil Ramesh M. 
Published: December 2010

AbstractA wide range of Pectin and Sodium Alginate blends have been investigated by casting films from aqueous solution. Blends showed synergy both in mechanical properties and water vapor permeation rate. Previously observed synergism in gels at low pH is also maintained in cast films of blends having up to 40% Pectin. Films were made water‐insoluble by post‐treatment with CaCl2, which develops physical crosslinks among the molecules of both polymers. After CaCl2 treatment, mechanical properties are drastically changed due to development of physically crosslinked tie points in the molecular network structure. The modulus and tensile strength of the resulting network structure are dependent on the nature of the polymers. Even in water insoluble films, synergism in mechanical and water barrier properties is retained in films having up to 20% Pectin content. Structural reorganization before and after CaCl2 treatment was investigated by X‐ray and dynamic mechanical analysis. The synergism observed in mechanical properties of the films before and after CaCl2 treatment is attributed to reduction in molecular mobility and change in molecular network structure. Structural reorganization in CaCl2‐treated films, and thereby film properties, is dependent on the compositions of the blends; blended films show sharp glassy‐rubbery transition in the storage modulus—temperature plot, which is not the case in untreated films. Film flexibility increases with increasing Pectin content in the blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Controlled release of berberine hydrochloride from alginate microspheres embedded within carboxymethyl chitosan hydrogels
Authors: Zhu Ai Mei , Hua Chen Jian , Liu Qing Lin , Jiang Yu Liang 
Published: December 2010

AbstractBerberine hydrochloride is a natural medicine with wide clinical application. In this article, berberine hydrochloride was entrapped into alginate microspheres via an emulsification/gelation method. The size distribution of the microspheres was determined by a laser particle sizer. Drug distribution within the microspheres was determined by confocal laser scanning microscopy. Those drug‐loaded microspheres were further entrapped into carboxymethyl chitosan (CMC) hydrogel to form a new drug‐delivery system (DDS). The surface morphology of the DDS was observed using metallographic microscopy and scanning electron microscopy (SEM). The compression strength of the DDSs with alginate microspheres was found significantly higher than that of the pure hydrogel. The drug‐release performances of the DDS in phosphate buffer solution (PBS, pH 7.4), saline solution (pH 6.3), and hydrochloric acid solution (HAS, pH 1.2) were also studied. Decay of the DDS in PBS within 72–80 h results in a faster release; however, the steady release in saline solution could last for all the testing period without cleavage of the DDS. In HAS, because of the shrinkage of the DDS, release is fast in the first period and remains steady later. The DDS exhibits prospective in controlled steady release of drugs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Study of rheological behavior during the recovery process of high impact polystyrene using cross‐WLF model
Authors: Peydró M. A. , Parres F. , Crespo J. E. , Juárez D. 
Published: December 2010

AbstractThe effect of reprocessing two mixtures: recycled high impact polystyrene (HIPS) with polybutadiene (PB); and HIPS with styrene‐ethylene‐butylene‐styrene (SEBS) have been studied in this article. To simulate recycled HIPS, we reprocessed virgin HIPS through five cycles. The virgin HIPS, the recycled HIPS, and the mixtures have been mechanically and rheologically characterized after the various cycles of reprocessing to evaluate their corresponding properties and correlate them with the number of cycles undergone. To widen our injection simulation analysis by computer (CAE: Computer Aided Engineering) of these new materials with additives, it was necessary to determine the viscosity using a mathematical model, in this case the Cross‐WLF, to determine the relevant parameters. Our results show that tensile strength increases, while the lengthening and viscosity decrease, as the number of reprocessing cycles increases. If we mix PB or SEBS with degraded HIPS, the mechanical properties of the virgin material are recovered and the rheological behavior maintains the viscosity values for the mixture with PB but these diminish notably for the mixture with SEBS. The results on mechanical properties show that the mixture with SEBS behaves better than the mixture with PB as the number of cycles increases. The viscosity of the mixture with SEBS diminishes more than the viscosity of the mixture with PB as the number of reprocessing cycles increases. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of tetraphenylphenyl‐modified fumed silica on silicone rubber radiation resistance
Authors: Diao Shen , Zhang Shengyou , Yang Zhizhou , Feng Shengyu , Zhang Changqiao , Wang Zhaohua , Wang Guogang 
Published: December 2010

AbstractTwo kinds of treated fumed silica were prepared by treatment with either tetraphenylphenyltriethoxysilane (TPHTS) or both tetraphenylphenyltriethoxysilane and hexamethyldisilazane (TPHMTS), and were used as reinforcing filler for silicone rubber. The resistance to irradiation of the silicone rubber obtained was investigated by gamma ray of dose 500 kGy in air. The mechanical properties and the average molecular weight between crosslinking points (Mc) of the silicone rubber were determined before and after irradiation. The results show that the fumed silica treated by tetraphenylphenyltriethoxysilane (TPHPHS) can effectively improve the radiation resistance of silicone rubber while the fumed silica treated by both tetraphenylphenyltriethoxysilane and hexamethyldisilazane (MMN) cannot only effectively improve the radiation resistance of silicone rubber but also has excellent reinforcing effect on silicone rubber. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Design and preparation of cross‐linked α‐methylstyrene‐acrylonitrile copolymer nano‐particles for elastomer reinforcement
Authors: Lu Ming , Zhou Jianjun , Wang Liansheng , Zhao Wei , Lu Yonglai , Zhang Liqun , Liu Yakang 
Published: December 2010

AbstractCrosslinked α‐methylstyrene and acrylonitrile (MStAN) copolymer particles in a latex form were synthesized by free radical emulsion polymerization. The particles took a spherical shape with an average size of 53.1 nm in a narrow distribution. When filled into styrene‐butadiene rubber (SBR), nitrile‐butadiene rubber (NBR), and natural rubber (NR), the MStAN nano‐particles exhibited excellent reinforcing capabilities and the best in NBR. By the employment of heat treatment, mechanical properties of the MStAN‐filled SBR composites had got remarkable further improvements. But mechanical properties, together with the morphology, of the MStAN‐filled NBR composites, varied little after heat treatment, which, however, divulged the naturally good compatibility between the MStAN particles and the NBR matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of calix[2]‐p‐benzo[4]pyrrole on the electrochemical properties of poly(ethylene oxide)‐based electrolytes for lithium batteries
Authors: Stephan A. Manuel , Prem Kumar T. , Angulakshmi N. , Salini P.S. , Sabarinathan R. , Srinivasan A. , Thomas Sabu 
Published: December 2010

AbstractPoly(ethylene oxide) based electrolytes comprising LiCF3SO3 and calix[2]‐p‐benzo[4]pyrrole (CBP) as anion binder were prepared and subjected to DSC, ionic conductivity, cationic transport number and FTIR analyses. Symmetric cells of the type Li/PEO+LiCF3SO3+CBP/Li were assembled with these electrolytes and evolution of interfacial resistance as a function of time was analyzed. The cationic transference number, t, was found to increase from 0.23 to 0.78 on incorporation of CBP in the polymer electrolyte (PE). The incorporation of CBP as an anion trap does not enhance ionic conductivity below 60°C although it improves the interfacial properties. FTIR study revealed the formation of Li–C compounds on the lithium surface upon contact with the CBP added membranes. The CBP added PE was found to be optimal in terms of ionic conductivity and transport number, t, above 70°C, which were found to be higher for a system previously reported with calix[6]pyrrole. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of formulation variables on cure kinetics, mechanical, and electrical properties of filled peroxide cured, ethylene‐propylene‐diene monomer compounds
Authors: Sengupta Saurav , Esseghir Mohamed , Cogen Jeffrey M. 
Published: December 2010

AbstractPeroxide crosslinkable ethylene–propylene–diene monomer (EPDM) compounds are formulated systems in which the base polymer generally comprises only a small fraction of the total composition. Knowledge of the intercomponent dependency is therefore crucial for successful product development. In this study, we have investigated the effect of formulation components on key material properties of cured, filled, and oil extended EPDM. In studying the impact of individual components, the clay filler was found to have a significant and negative effect on cure performance and to a lesser extent on the dielectric strength as well. On the other hand, the oil plasticizer was found to have a positive effect on recovery of the cure efficiency in filled compounds. It was also found that the interaction of the filler, the plasticizer oil, and the peroxide impacted both the mechanical properties as well as the dielectric strength. Given the complexity of the system, a statistical experimental design method was adopted to study the interactions of the components and their impact of final properties. For selected compositions, the cure behavior and the evolution of properties with extent of cure were studied. The cure was also modeled and compared to previously proposed models available in the literature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Prokaryotic gene clusters: A rich toolbox for synthetic biology
Authors: Fischbach Michael , Voigt Christopher A. 
Published: December 2010

AbstractBacteria construct elaborate nanostructures, obtain nutrients and energy from diverse sources, synthesize complex molecules, and implement signal processing to react to their environment. These complex phenotypes require the coordinated action of multiple genes, which are often encoded in a contiguous region of the genome, referred to as a gene cluster. Gene clusters sometimes contain all of the genes necessary and sufficient for a particular function. As an evolutionary mechanism, gene clusters facilitate the horizontal transfer of the complete function between species. Here, we review recent work on a number of clusters whose functions are relevant to biotechnology. Engineering these clusters has been hindered by their regulatory complexity, the need to balance the expression of many genes, and a lack of tools to design and manipulate DNA at this scale. Advances in synthetic biology will enable the large‐scale bottom‐up engineering of the clusters to optimize their functions, wake up cryptic clusters, or to transfer them between organisms. Understanding and manipulating gene clusters will move towards an era of genome engineering, where multiple functions can be “mixed‐and‐matched” to create a designer organism.
Development and validation of a liquid chromatography—tandem mass spectrometry method to determine ulifloxacin, the active metabolite of prulifloxacin in rat and rabbit plasma: application to toxicokinetic study
Authors: Roy Bikash , Choudhury Hira , Das Ayan , Das Anjan Kumar , Pal Tapan Kumar 
Published: December 2010

AbstractA simple, high‐throughput and specific high‐performance liquid chromatography–tandem mass spectrometry method has been developed and validated according to the FDA guidelines for quantification of ulifloxacin in rat and rabbit plasma. The analyte was separated on a Peerless basic C18 column (33 × 4.6 mm, 3 µm) with an isocratic mobile phase of methanol–water containing formic acid (0.5%, v/v; 9:1, v/v) at a flow rate of 0.5 mL/min. The MS/MS detection was carried out by monitoring the fragmentation of m/z 350.500 → 248.500 for ulifloxacin and m/z 332.400 → 231.400 for ciprofloxacin (internal standard; IS) on a triple quadrupole mass spectrometer. The response to ulifloxacin was linear over the range 0.010–2.500 µg/mL in both plasma. The limit of detection and lower limit of quantification of ulifloxacin were determined in both species to be 0.0025 and 0.010 µg/mL, respectively. The method was successfully applied to quantitatively assess the toxicokinetics of ulifloxacin in rat and rabbit following a single 400 mg/kg (in rat) and 200 mg/kg (in rabbit) oral dose of the prulifloxacin. Copyright © 2010 John Wiley & Sons, Ltd.
Reversed‐phase liquid chromatographic determination of tramiprosate in rat plasma using evaporative light scattering detector
Authors: Rao R. Nageswara , Maurya Pawan K. , Shinde Dhananjay D. , Agwane Sachin B. 
Published: December 2010

AbstractA simple and reliable method was developed for determining blood concentrations of tramiprosate using reversed‐phase HPLC with evaporative light scattering detection. The optimum evaporator and nebulizer temperatures for ELSD were set at 90 and 60°C respectively. The method was linear for a concentration range of 10–1000 µg/mL when 0.3 mL blood was used. The intra‐assay precision ranged from 1.84 to 5.24%, and the coefficient of variation (CV) for a quality control sample at 10 µg/mL was 5.24% with a bias of −9.50% from the target value. The inter‐assay precision ranged from 2.58 to 5.96%, and the CV for a quality control sample at 10 µg/mL was 5.96% with a bias of −7.50% from the target value. The method described here is suitable for management of tramiprosate in Alzheimer disease therapy. Copyright © 2010 John Wiley & Sons, Ltd.
Determination of tryptophan and kynurenine in human plasma by liquid chromatography–electrochemical detection with multi‐wall carbon nanotube‐modified glassy carbon electrode
Authors: Liu Lihong , Chen Ying , Zhang Yulin , Wang Fang , Chen Zilin 
Published: December 2010

AbstractA novel method was developed for the simultaneous determination of kynurenine and tryptophan by high‐performance liquid chromatography with electrochemical detection at multi‐wall carbon nanotube (MWCNT)‐modified glassy carbon electrode. The separation and detection conditions were optimized. The typical HPLC experiments were conducted by using a reversed‐phase ODS column with a mobile phase consisting of stock acetate buffer (pH 5)–methanol (4:1, v/v) using an isocratic elution at the flow rate of 1.0 mL/min. The obtained LODs for kynurenine and tryptophane were 0.5 and 0.4 µmol/L, respectively. The analytical method for human plasma samples was validated and confirmed by LC‐UV and LC‐MS. The recoveries were in the range of 84.8–110%, and the precision was lower than 5.9%. Copyright © 2010 John Wiley & Sons, Ltd.
Validated HPLC method for the quantitative determination of CoQ10 in dog plasma and its application to a pharmacokinetic study
Authors: Yuan Bo , Liu Chunling , Xu Pingwei , Lin Lin , Pan Cheng , Wang Linglan , Xu Haiyan 
Published: December 2010

AbstractCoenzyme Q10 (CoQ10) is a naturally occurring compound located in all membranes throughout the cell. A rapid and sensitive HPLC method was developed to determine the concentration of CoQ10 in dog plasma using a surrogate matrix. Chromatographic separation was carried out on a Diamonsil C18 column with the UV detector set at 275 nm. Methanol–2‐propanol (40:60, v/v) was used as a mobile phase delivered at a flow rate of 1.0 mL/min. Calibrators were prepared using blank plasma–K2HPO4 buffer (50 mm, pH 8.0)–saline (1:3:6, v/v/v) as surrogate matrix. It was shown that the surrogate matrix had similar properties to dog plasma for CoQ10 in extraction, freeze–thaw and stability. The assay was linear over the concentration range of 0.10–100 µg/mL. The intra‐ and inter‐day precisions were within 13.3% in terms of relative standard deviation (RSD%) and the accuracy was within ±7.5% in terms of relative error. This simple and reproducible HPLC method with less plasma volume (0.4 mL) and adequate sensitivity was successfully applied to pharmacokinetic studies of CoQ10 in dogs and an investigation of the effect of CoQ10 formulation on CoQ10 baseline levels. Copyright © 2010 John Wiley & Sons, Ltd.
The evolution of partial least squares models and related chemometric approaches in metabonomics and metabolic phenotyping
Authors: Fonville Judith M. , Richards Selena E. , Barton Richard H. , Boulange Claire L. , Ebbels Timothy M. D. , Nicholson Jeremy K. , Holmes Elaine , Dumas Marc‐Emmanuel 
Published: December 2010

AbstractMetabonomics is a key element in systems biology, and with current analytical methods, generates vast amounts of quantitative or qualitative metabolic data. Understanding of the global function of the living organism can be achieved by integration of ‘omics’ approaches including metabonomics, genomics, transcriptomics and proteomics, increasing the complexity of the full data sets. Multivariate statistical approaches are well suited to extract the characterizing metabolic information associated with each level of dynamic process. In this review, we discuss techniques that have evolved from principal component analysis and partial least squares (PLS) methods with a focus on improved interpretation and modeling with respect to biomarker recovery and data visualization in the context of metabonomic applications. Visualization is of paramount importance to investigate complex metabolic signatures, the power and potential of which is illustrated with key papers. Recent improvements based on the removal of orthogonal variation are discussed in terms of interpretation enhancement, and are supported by relevant applications. Flexibility of PLS methods in general and of O‐PLS in particular allows implementation of derivative methods such as O2‐PLS, O‐PLS‐variance components, nonlinear methods, and batch modeling to improve analysis of complex data sets, which facilitates extraction of information related to subtle biological processes. These approaches can be used to address issues present in complex multi‐factorial data sets. Thus, we highlight the key advantages and limitations of the different latent variable applications for top‐down systems biology and assess the differences between the methods available. Copyright © 2010 John Wiley & Sons, Ltd.
Hydrotalcite‐Supported Gold Catalyst for the Oxidant‐Free Dehydrogenation of Benzyl Alcohol: Studies on Support and Gold Size Effects
Authors: Fang Wenhao , Chen Jiashu , Zhang Qinghong , Deng Weiping , Wang Ye 
Published: December 2010

AbstractGold nanoparticles with uniform mean sizes (≈3 nm) loaded onto various supports have been prepared and studied for the oxidant‐free dehydrogenation of benzyl alcohol to benzaldehyde and hydrogen. The use of hydrotalcite (HT), which possesses both strong acidity and strong basicity, provides the best catalytic performance. Au/HT catalysts with various mean Au particle sizes (2.1–21 nm) have been successfully prepared by a deposition–precipitation method under controlled conditions. Detailed catalytic reaction studies with these catalysts demonstrate that the Au‐catalyzed dehydrogenation of benzyl alcohol is a structure‐sensitive reaction. The turnover frequency (TOF) increases with decreasing Au mean particle size (from 12 to 2.1 nm). A steep rise in TOF occurs when the mean Au particle size becomes smaller than 4 nm. Our present work suggests that the acid–base properties of the support and the size of Au nanoparticles are two key factors controlling the alcohol dehydrogenation catalysis. A reaction mechanism is proposed to rationalize these results. It is assumed that the activation of the β‐CH bond of alcohol, which requires the coordinatively unsaturated Au atoms, is the rate‐determining step.
Recursive politics: prevention, modernity and social systems
Authors: Freeman Richard 
Published: December 2010

The aim of this paper is to connect the recent interest in prevention to recent developments in social theory. It begins by recovering some of prevention's essential features from the realm of common sense, showing that what is taken to be the common sense of prevention is emblematic of modernity. For prevention is built on scientific understandings of cause and effect and the possibility of prediction; on a capacity for controlled intervention by government in social life; on a universal value base; on the authority of professional expertise; on rational, calculating, individual social subjects. As this order develops and changes, many of its constituent elements begin to be threatened by social processes which it has itself set in train. Prevention is affected by (and implicated in) these changes, too. But far from being eclipsed by them it becomes more prominent.Drawing on systems theory, the paper argues that prevention meets the essential purpose of boundary maintenance by which the functioning of social systems is sustained. For reasons both external and internal to welfare agencies, including an increased burden of social risk and increasing organisational complexity, this need to mark and maintain system boundaries is ever more pressing. At the same time, at least part of the problem of the fragility of boundaries is attributable to attempts to maintain them. It is for this reason that preventive policy making can be described as recursive, or self‐propelling. Copyright © 1999 John Wiley & Sons, Ltd.
Tetrakisphosphates and Bispyrophosphates ofmyo‐Inositol Derivatives as Allosteric Effectors of Human Hemoglobin: Synthesis, Molecular Recognition, and Oxygen Release
Authors: Koumbis Alexandros E. , Duarte Carolina D. , Nicolau Claude , Lehn Jean‐Marie 
Published: December 2010

AbstractVarious 2,5‐ and 1,4‐substituted and unsubstitutedmyo‐inositol tetrakisphosphates and bispyrophosphates were prepared following a general synthetic pathway. All final compounds were tested for their capability to induce oxygen release from human hemoglobin. Most of these proved to be efficient allosteric effectors, with similar affinities for hemoglobin to that ofmyo‐inositol hexakisphosphate, which is one of the best known allosteric effectors of hemoglobin. The efficacy was found to be higher for free phosphates than pyrophosphates. As allosteric Hb effectors, these compounds enable enhanced oxygen release. These effects increase with the strength of Hb binding and correspond primarily to electrostatic interactions. Stereochemical and steric factors also play a significant but secondary role in molecular recognition. In view of the central role played by hypoxia in numerous types of diseases, the exploration ofmyo‐inositol phosphate derivatives represents an important avenue in the search for substances which act on the oxygenation status of tissues and may have significant potential in the discovery and development of novel drug candidates.