bluuebunny/crossref_metadata_2025_split huggingface dataset:
FT‐Raman spectroscopic study of thoracic aortic wall subjected to uniaxial stress
Authors: Hanuza J. , Ma̧czka M. , Ga̧sior‐Głogowska M. , Komorowska M. , Kobielarz M. , Bȩdziński R. , Szotek S. , Maksymowicz K. , Hermanowicz K. 
Published: December 2009

AbstractThe combination of Fourier transform‐Raman spectroscopy and uniaxial tensile tests (in MTS Synergie 100 testing machine) was used to investigate microstructural changes in the secondary protein structure of the aortic wall under different levels of stress. The spectroscopic analysis clearly shows differing tension thresholds for material excised in two directions: circumferential and longitudinal. This is confirmed by the results of macroscopic mechanical analyses. The application of strain does not lead to any noticeable change in the bandwidths of the Raman bands. The stress‐controlled Raman band analysis shows that the modes at 938 cm−1 assigned as CαC of the α‐helix, 1660 cm−1 amide I (the unordered structure of elastin) and 1668 cm−1 amide I (the collagen triple helix) undergo wavenumber shifting, but the bands at 1004 cm−1 assigned to the phenyl ring breathing mode and 2940 cm−1 to the ν (CH3) and ν (CH2) modes are not affected during the elastic behaviour. A clear correlation between Raman band shifting and the level of mechanical stress has been established. Elastin alone participates in the transmission of low stresses in the circumferential direction, whereas both elastin and collagen take part in the transmission of physiological and higher stresses. Copyright © 2009 John Wiley & Sons, Ltd.
Physicochemical properties of octenyl succinic anhydride‐modified potato starch with different degrees of substitution
Authors: Wang Junping , Su Lianghua , Wang Shuo 
Published: December 2009

AbstractBACKGROUND: Esterified starch is an important type of modified starch. In particular, octenyl succinic anhydride‐modified starch (OSA starch) is widely used in the food industry. However, there has been little research on the properties of products with different degrees of substitution (DS). Therefore the aim of this study was to analyse the physicochemical properties of products with different DS.RESULTS: OSA starch samples with different DS were prepared from potato starch. Two new peaks were observed in the Fourier transform infrared spectrum, one at 1724 cm−1 due to CO and one at 1572 cm−1 due to RCOO. Emulsifying capacity and emulsion stability improved with increasing DS. Rheological analysis showed the occurrence of the ‘shear‐thinning’ phenomenon, the viscosity of the sample with DS = 0.0211 being even lower than that of native starch. A decrease in syneresis rate from 88.3% (native starch) to 39.0% (DS = 0.0211) indicated that freeze–thaw stability was improved.CONCLUSION: The physicochemical properties of OSA potato starch were better than those of native potato starch. Freeze–thaw stability, emulsifying capacity and emulsion stability improved with increasing DS. Viscosity increased at lower DS but decreased at DS = 0.0211. Copyright © 2009 Society of Chemical Industry
Is the tourism‐led growth hypothesis stable for Malaysia? A note
Authors: Lean Hooi Hooi , Tang Chor Foon 
Published: December 2009

AbstractThis letter extends the Gunduz and Hatemi‐J study on the tourism‐led growth hypothesis with the Malaysian data. The rolling subsample causality test was employed to demonstrate the validity and stability of the tourism–growth causality relationship. Our result shows the causality relationship is valid and stable over the sample period. Copyright © 2009 John Wiley & Sons, Ltd.
Metal‐complex formation and DNA interaction of 5, 10,15,20‐tetrakis(1‐methyl‐4‐pyridiyl)‐porphine: Study of the mechanistic aspects
Authors: Aydinoglu Sabriye , Biver Tarita , Secco Fernando , Venturini Marcella 
Published: December 2009

AbstractThe macrocyclic porphyrin 5,10,15,20‐tetrakis(1‐methyl‐4‐pyridiyl)‐porphine is studied in its ability to coordinate Cu(II) even at very low pH values and to interact, as a copper complex, with calf‐thymus (CT‐DNA). The kinetics and equilibria for metal‐ligand complexes formation are spectrophotometrically studied, particularly focussing on the mechanistic information provided by the kinetic approach. The rate constants of complex formation is much lower than that of water exchange at Cu(II); this behavior is ascribed to an equilibrium between two porphyrin populations, only one of them being reactive. Concerning the interaction of the copper–porphyrin complex (D) with CT‐DNA, it has been found that the complex binds to G–C base pairs by intercalation while forms external complex with the A–T base pairs. The kinetic results agree with a reaction mechanism that takes into account the slow shuffling from an AT‐bound form (DAT) to a GC‐bound form (DGC) of the copper complex (D), finally leading to a more stable DGC* intercalated form. Kinetic and equilibrium parameters for the copper complex binding to the nucleic acid are obtained, and the binding mechanism is discussed. A mechanism is proposed where D reacts simultaneously with (G–C) and (A–T) base pairs. The resulting bound forms interconvert according to a “shuffling” process, which involves formation of an intermediate (DGC) form. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 79–89, 2010
Corrosion inhibition of copper in tetra‐n‐butylammonium bromide aqueous solution by benzotriazole
Authors: Liu S. , Duan J. M. , Jiang R. Y. , Feng Z. P. , Xiao R. 
Published: December 2009

AbstractThe corrosion inhibition behavior of benzotriazole (BTA) on copper in 17 wt% tetra‐n‐butylammonium bromide (TBAB) aerated aqueous solution was investigated by weight‐loss tests, potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy/energy dispersive X‐ray spectroscopy. BTA is a good inhibitor in 17 wt% TBAB solution. The inhibition efficiency of BTA increases with increasing inhibitor concentration, attaining efficiencies of up to 90% calculated according to different methodologies. Adsorption of BTA in 17 wt% TBAB solution on the copper surface was found to obey the Langmuir adsorption isotherm.
Fullerene Substitution of Donor/Acceptor Branched Disubstituted Polyacetylenes: Significantly Accelerated Polymerization by the C60 Pendant
Authors: Li Minghua , Li Xiaofang , Xu Pan , Yang Shangfeng 
Published: December 2009

AbstractA novel type of soluble donor/acceptor branched disubstituted polyacetylene (PA–C60) bearing C60 and soft pentyl moieties in side‐chains was synthesized successfully. The product has been characterized by FTIR, 1H NMR, 13C NMR, CH COSY, UV‐vis, and fluorescence spectroscopies, confirming its branched polymeric structure comprising polyacetylene chains and covalently bound C60 cages in side‐chains. Surprisingly, completely different from the conventional metathesis polymerization of acetylenes, it is found for the first time that the disubstituted monomer 4 can be polymerized within a very short reaction time (up to 1.5 min) and the molecular weight of the synthesized PA–C60 is independent of the reaction time. A plausible interpretation is proposed to understand the rapid polymerization reaction accelerated by the C60 pendant. The optical properties of PA–C60 were studied by UV‐vis absorption and fluorescence spectroscopies, which indicated that the fluorescence of PA–C60 is significantly enhanced compared to monomer 4, presumably due to its branched structure. SEM studies on the thin film morphology of PA–C60 in comparison with monomer 4 suggested the successful polymerization of monomer 4 and revealed that PA–C60 has a much smoother morphology than the aggregated morphology of monomer 4.magnified image
A New Synthetic Approach to Thiophene‐Nickel(II)porphyrin Hybrid Molecules and their Electrochemical and Computational Investigation
Authors: Zöllner Mike J. , Frähmcke Jan S. , Elstner Marcus , Jahn Ullrich , Jones Peter G. , Becker Eike , Kowalsky Wolfgang , Johannes Hans‐Hermann 
Published: December 2009

AbstractNew synthetic strategies for thiophene‐nickel(II)porphyrin hybrid molecules are described. Three principles—linear direct, linear spacer and lateral spacer connectivities—were realised and compared with respect to their electrochemical behaviour. Computational investigations by DFT methods confirm experimental data and explain cylic voltammetric oxidations. For the linear direct connectivity, the number of thiophene units per substituted position must be at least two, since the porphyrin core acts as conjugation breaker and hinders the formation of higher oligomers. Alternatively an ethynylene spacer can be introduced to increase conjugation and to optimise the conducting properties. The lateral spacer connection mode proved to be best suited to the electrochemical formation of hybrid compounds.magnified image
In situ Synthesis of Polymer/Clay Nanocomposites by Living and Controlled/Living Polymerization
Authors: Tasdelen Mehmet Atilla , Kreutzer Johannes , Yagci Yusuf 
Published: December 2009

AbstractThe present trend article reports on the recent progress of the in situ synthesis of polymer/clay nanocomposites with well‐defined structures and highly exfoliated morphologies. The methods used for the preparation are classified according to the individual polymerization mechanisms. Other possibilities such as multi‐mode polymerization that combines different polymerization methods and click chemistry are also described. A special emphasis is devoted to the structures and morphologies of the obtained nanocomposites rather than their practical properties.magnified image
Formulation and Evaluation af a Novel Adhesive Film for Use in Composite Patch Repair
Authors: Tsamasphyros G. , Kalkanis K. , Maroulas P. , Anthoulis G. I. , Grigoryeva O. 
Published: December 2009

AbstractThe current work focuses on the testing of a novel material used as an adhesive film in Composite Patch Repair (CPR). A series of Differential Scanning Calorimetry (DSC) results along with various curing cycles not only led to the optimum material composition but also demonstrated the compatibility to the composite pre‐impregnated patches. This in turn was subjected to mechanical testing including shear strength measurements. The substrate was chosen to be 2017 T4 aluminium alloy which is customarily used in the aerospace industry, taking into account that CPR is a technique mainly applied in this field. The subsequent surface preparation of the specimens was investigated for the specified context resulting to the selection of the Ferric Sulphate Sulphuric acid etching process. Finally, a series of specimens representing actual skin repairs were created and subjected to cyclic loading, specifying the suitability of the novel material, compared to commercially available materials.
Towards a Non Empirical Kinetic Model for the Lifetime Prediction of Polyethylene Pipes Transporting Drinking Water
Authors: Colin Xavier , Audouin Ludmila , Verdu Jacques 
Published: December 2009

AbstractA kinetic model has been elaborated to predict the lifetime of polyethylene pipes transporting slightly pressurized (3–12 bars) drinking water disinfected by free radical reagents. This model is composed of three levels: i) A system of differential equations, derived from a mechanistic scheme for radical chain oxidation in the presence of free radical reagents, giving access to the spatial distribution (in the pipe wall) of oxidation products and stabilizer concentration; ii) Equations allowing to predict the profiles of average molar masses from the spatial distribution of chain scissions and crosslinking events; iii) An empirical creep equation and a failure criterion derived from regression curves obtained in pure water (without disinfectant). It is assumed that the chemical degradation modifies only the time to transition between ductile and brittle regimes of failure, and that this time is linked to the weight average molar mass according to the classical power law. By superimposing these three levels, it is possible to predict the time to failure under the coupled effects of pressure and chemical degradation. This model is successfully applied to the case of chlorine dioxide.
Degradation of Plasticized PVB During Reprocessing by Kneading
Authors: Měřínská D. , Tupý M. , Kašpárková V. , Popelková J. , Zvoníček J. , Pištěk D. , Svoboda P. 
Published: December 2009

AbstractPossibility and conditions for optimal re‐processing of plasticized polyvinylbutyral (PVB) were tested. The aim of this work was to investigate degradation of PVB sheet at various kneading conditions and to estimate the influence of temperature, air oxygen and mechanical stress on the progress of degradation process. In order to confirm the influence of humidity on the PVB properties during reprocessing, the sheets with the humidity content of 0.5 and 8.0% were tested. The PVB degradation was determined from the changes of melt flow index, mechanical properties in terms of stress and elongation at break, yellowness and molecular weight distribution. The optimal recycling conditions for PVB were estimated from the evaluation of all measured properties and their changes.
Effect of Initiator on the Over‐Voltage Positive Temperature Coefficient of Linear Low Density Polyethylene/Carbon Black Nano Composites
Authors: Tsai Ching‐Shan , Liu Chia‐I , Tsao Keng‐Yu , Chen Kan‐Nan , Yeh Jen‐Taut , Huang Chi‐Yuan 
Published: December 2009

AbstractThe composite of linear low density polyethylene (LLDPE) with carbon black (CB) and inorganic flame retardant (aluminum hydroxide, Al(OH)3) was prepared by melt‐blending method. The effect of cross‐linking on the stability of positive temperature coefficient (PTC) of composite and the elimination of negative temperature coefficient (NTC) of composite were investigated. LLDPE was chemically cross‐linking with different contents of initiator (dicumyl peroxide, DCP). The cross‐linking effects of composite were analyzed by gel content analysis, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). By the effect of DCP, not only the composite appeared a high PTC intensity, but also the NTC effect of composite was eliminated. In this investigation, the optimum PTC intensity of composite reached 5.87 orders of magnitude for the composition of LLD0.l0C33.7A28, and the PTC transitional temperature of composite decreased with increasing of DCP content. In addition, the good reproducibility of composites was proved by thermal cycling, and successfully passed the test of over‐voltage resistance.
DPD Simulations of PMMA‐Oleic Acid Mixture Behaviour in Organic Capped Nanoparticle Based Polymer Nanocomposite
Authors: Bianchino E. , Piotto S. , Mavelli F. , Curri M. L. , Striccoli M. 
Published: December 2009

AbstractDissipative Particle Dynamics has been used to investigate the different morphology of polymer nanocomposites. Such a study was addressed to the definition of a suitable tool for understanding the distribution of oleic acid (OA) capped nanoparticles embedded into poly‐methylmethacrylate (PMMA) matrix for the formation of nanocomposite materials. In particular, simulations of PMMA/OA mixtures at different composition have exhibited the self‐assembly of amphiphiles to form separated nanosized domains with different morphologies going from spheres, to tubules up to the formation of continuous planar sheets as the OA composition increases. On the other hand, simulations carried out on nanocomposite systems have shown that NPs do not perturb the observed phase behaviour of PMMA/OA mixtures. In fact, at low OA compositions nanoparticles are confined in the spherical lipid domains to form NP clusters, while at high OA composition NPs appear homogeneously distributed in the continuous lipid domain.
Reorientational Dynamics of Polyethylene Glycol/PAMAM Dendrimer Blends
Authors: Ristić Sanja , Mijović Jovan 
Published: December 2009

AbstractThe reorientational dynamics of dipoles in a series of blends of Polyethylene Glycol (PEG) and poly(amidoamine) (PAMAM) dendrimers were investigated by broadband dielectric relaxation spectroscopy (DRS). Measurements were performed over a wide range of frequency and temperature. Neat PEG exhibits three relaxation processes: the segmental process in the amorphous phase and two faster processes due to the localized motions in the amorphous regions and the rotation of hydroxyl end groups. Addition of dendrimers to the PEG matrix slows down the segmental process in the amorphous phase, but has no effect on the relaxation time of local processes in PEG. However, H‐bonding which forms between the PEG oxygen and the amino groups on dendrimer surface is responsible for a shift of local processes in dendrimers to lower frequency. A detail analysis of the effect of temperature, concentration of dendrimers and molecular weight of PEG on the relaxation dynamics is offered.
Binding affinity of tea catechins for HSA: Characterization by high‐performance affinity chromatography with immobilized albumin column
Authors: Ishii Takeshi , Minoda Kanako , Bae Min‐Jung , Mori Taiki , Uekusa Yoshinori , Ichikawa Tatsuya , Aihara Yoshiyuki , Furuta Takumi , Wakimoto Toshiyuki , Kan Toshiyuki , Nakayama Tsutomu 
Published: December 2009

AbstractCatechins are the major polyphenols in green tea leaves. Recent studies have suggested that the catechins form complexes with HSA for transport in human blood, and their binding affinity for albumin is believed to modulate their bioavailability. In this study, the binding affinities of catechins and their analogs were evaluated and the relationship between the chemical structure of each catechin and its binding property were investigated. Comparing these catechins by HPLC analysis with the HSA column, we showed that galloylated catechins have higher binding affinities with HSA than non‐galloylated catechins. In addition, pyrogallol‐type catechins have a high affinity compared to catechol‐type catechins. Furthermore, the binding affinity of the catechin with 2,3‐trans structure was higher than those of the catechin with 2,3‐cis structure. The importance of the hydroxyl group on the galloyl group and B‐ring was confirmed using methylated catechins. These results indicate that the most important structural element contributing to HSA binding of tea catechins is the galloyl group, followed by the number of hydroxyl groups on the B‐ring and the galloyl group or the configuration at C‐2. Our findings provide fundamental information on the relationship between the chemical structure of tea catechins and its biological activity.
Effect of pistachio oil on gene expression of IFN‐induced protein with tetratricopeptide repeats 2: A biomarker of inflammatory response
Authors: Zhang Jun , Kris‐Etherton Penny M. , Thompson Jerry T. , Vanden Heuvel John P. 
Published: December 2009

AbstractWhen incorporated into the diet, pistachios have a beneficial effect on lipid and lipoprotein profiles. However, little is known about potential anti‐inflammatory properties. This study was conducted to determine whether pistachio oil and an organic extract from pistachio oil extract (PE) regulated expression of inflammation‐related genes. A mouse macrophage cell line (RAW 264.7 cells) was treated with pistachio oil and gene expression microarray analyses were performed. Pistachio oil significantly affected genes involved in immune response, defense response to bacteria, and gene silencing, of which INF‐induced protein with tetratricopeptide repeats 2 (Ifit‐2) was the most dramatically reduced. PE reduced the LPS‐induced Ifit‐2 by 78% and the bioactive molecules contained in PE, linoleic acid, and β‐sitosterol recapitulated this inhibition. Promoter analysis identified two adjacent IFN‐stimulated response elements, which lie between −110 and −85bp of the 5′‐flanking region of the Ifit‐2 promoter, as being responsive to LPS activation and inhibition by PE. Our results indicate that pistachio oil and bioactive molecules present therein decrease Ifit‐2 expressions, and due to the sensitivity of this effect, this gene is a potential biomarker for monitoring diet‐induced changes in inflammation.
Pyrrolizidine alkaloids in pollen and pollen products
Authors: Kempf Michael , Heil Sandra , Haßlauer Iris , Schmidt Lukas , von der Ohe Katharina , Theuring Claudine , Reinhard Annika , Schreier Peter , Beuerle Till 
Published: December 2009

AbstractRecently, 1,2‐dehydropyrrolizidine alkaloid (PA) ester alkaloids, found predominantly as their N‐oxides (PANOs, pyrrolizidine N‐oxides), have been reported in both honey and in pollen obtained directly from PA plants and pollen loads collected by bees, raising the possibility of health risks for consumers of these products. We confirm these findings in regard to floral pollen, using pollen collected directly from flowers of the known PA plants Senecio jacobaea, S. vernalis, Echium vulgare and pollinia of Phalaenopsis hybrids, and we extend analyses of 1,2‐unsaturated PAs and 1,2‐unsaturated PANOs to include bee‐pollen products currently being sold in supermarkets and on the Internet as food supplements. PA content of floral pollen ranged from 0.5 to 5 mg/g. The highest values were observed in pollen obtained from Senecio species. Up to 95% of the PAs are found as PANOs. Detailed studies with S. vernalis revealed unique PA patterns in pollen and flowers. While seneciphylline was the most prominent PA in S. vernalis pollen, the flowers were dominated by senecionine. To analyze trace amounts of 1,2‐unsaturated PAs in pollen products, our previously elaborated method consisting of strong cation exchange‐SPE, two reduction steps followed by silylation and subsequent capillary high‐resolution GC‐MS using SIM mode was applied. In total, 55 commercially available pollen products were analyzed. Seventeen (31%) samples contained 1,2‐unsaturated PAs in the range from 1.08 to 16.35 μg/g, calculated as retronecine equivalents. The 1,2‐unsaturated PA content of pollen products is expressed in terms of a single sum parameter and no background information such as foraged plants, pollen analysis, etc. was needed to analyze the samples. The detection limit of overall procedure and the reliable quantitation limit were 0.003 and 0.01 μg/g, respectively.
Chemische Konzepte für saubere Abgase
Authors: Kohse‐Höinghaus Katharina 
Published: December 2009

AbstractDie kontrollierte Nutzung des Feuers machte eine ungeheure technologische Entwicklung möglich. Sie verursacht jedoch auch gesundheitsschädliche und klimawirksame Emissionen. Neue Verbrennungskonzepte sollen zur Lösung des Problems beitragen.
Totalsynthese des Galbulimima‐Alkaloids (—)‐Himandrin
Authors: Graening Timm 
Published: December 2009

AbstractEine [3+3]‐Annelierung über eine zweifache Enamin‐Addition ist das synthetische Kernstück bei der Himandrin‐Synthese. Verbunden mit der NCS‐vermittelten Spirocyclisierung auf einer späten Stufe reduziert es das Syntheseproblem auf elegante Weise auf zwei vereinfachte Synthesebausteine.
Harmonie und Dissens:Ostwalds Spuren in Dresden
Authors: Reschetilowski Wladimir , Hegewald Heiner 
Published: December 2009

AbstractVon 1887 bis 1906 lehrte Wilhelm Ostwald, der Chemie‐Nobelpreisträger des Jahres 1909, an der Universität Leipzig. Doch auch zur sächsischen Residenz‐ und späteren Landeshauptstadt Dresden und ihren Persönlichkeiten aus Staat, Wissenschaft und Wirtschaft unterhielt Ostwald freundschaftliche, manchmal auch kontroverse Beziehungen.
”Grund zu neuer Hoffnung“
Authors: Guggolz Ernst , Bulmahn Maren 
Published: December 2009

AbstractÜber die wirtschaftliche Lage und darüber, wie entscheidend Anwendungstechnik für den Unternehmenserfolg ist, sprach Charlie Crew, Präsident und CEO von Sabic Innovative Plastics, mit den Nachrichten aus der Chemie.