bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relevance of backbiting and beta‐scission reactions in the free radical polymerization of Acrylonitrile
Authors: Dossi M. , Storti G. , Moscatelli D. 
Published: March 2010

AbstractSummary: In this work, backbiting and beta‐scission reactions are investigated through Quantum Chemistry methods by adopting the Becke 3 parameters and Lee Yang Parr functional (B3LYP) and 6‐31G(d,p) basis set. Namely, the 1:3, 1:5 and 1:7 backbiting reactions are studied for acrylonitrile polymerization. It was found that the backbiting 1:5 is the most favorited because this kinetic event leads to the formation of a 6 membered transition state, while the backbiting 1:3 requires high activation energy due to the formation of a highly strained 4 membered ring. 7:3 backbiting reaction was also examined, since it is an alternative pathway that can explain the formation of defects generated by radicals in the third position. Simulations showed that this kinetic step is characterized by high rate constant because of its low activation energy.The right and left beta‐scission reactions from the mid chain radicals formed by the considered backbiting reactions are also studied. Computational analysis demonstrated that all beta‐scission reactions are endothermic and both the right and left beta‐scission reactions have the same activation energy, which seems to be more influenced by the position of the mid chain radical.
Synthesis of Polyacrylic/Silica Nanocomposite Latexes using Static Mixer
Authors: Farzi G. A. , Bourgeat‐Lami E. , McKenna T. F. L. 
Published: March 2010

AbstractSummary: Static mixers (Sulzer Chemtech; SMX) were used to prepare silica/ MMA‐co‐BA miniemulsions that were polymerized to produce nanocomposite latexes. Acceptable conditions for the formulation of polymerizable nanodroplets were found and subsequently used to produce silica/poly(MMA‐co‐BA) nanocomposites. The droplet size distribution of the resulting miniemulsions was narrow enough that it could be successfully polymerized. It was found that the droplet size depends on the silica content and increases with increasing the silica concentration. It was also shown that there is a relationship between the droplet size and the viscosity of the dispersed phase. The majority of droplets were nucleated upon polymerization when less than 15% silica was used. However, when the silica content exceeded 15%, the ratio of the number of particles in the final latex to the number of droplets (Np/Nd) increased to value much higher than 1 indicating the occurrence of homogeneous nucleation.
Investigation of the Mixing‐ and Devolatilization Behavior in a Continuous Twin‐Shaft Kneader
Authors: Seck Oliver , Maxisch Tobias , Warnecke Hans‐Joachim , Bothe Dieter 
Published: March 2010

AbstractSummary: The technical synthesis and processing of polymer materials is the basis for major branches of the chemical industry. Well introduced for high‐viscosity processes are screw extruders. However, in case of large residence times a large volume kneader is more appropriate, but the latter still requires further understanding for intensification purposes. To achieve this, silicone oil of high viscosity is used as kneading material. First, the axial mixing behavior is characterized by studying the residence time distribution. The response functions show that the classical dispersion model leads to an appropriate description of the experimental data. By means of a fast chemical reaction of second order the radial mixing behavior including transport on the molecular scale is studied. The amount of detected product is a measure for the contact‐area produced by kneading and therefore for the mixing efficiency. Furthermore, the mass transfer from the silicone oil phase to the gas phase is investigated in two cases. Firstly, the transfer component is dissolved in the liquid phase and, secondly, it is dispersed in it. Both industry relevant cases are experimentally and theoretically investigated. The kneader enables high surface renewal and larger concentration gradients for the efficient mass transfer.
Long‐Range Processing Correlation and Morphological Fractality of Compatibilized Blends of PS/ HDPE/ SEBS Block Copolymer
Authors: Jelčić Želimir , Vranješ Nina , Rek Vesna 
Published: March 2010

AbstractSummary: Processing and compatibilization effects of a commercially available styrene/ ethylene‐butylene/ styrene (SEBS) compatibilizer on the morphological structure, rheological and mechanical properties of blends of polystyrene (PS) and high density polyethylene (HDPE) were investigated. The rheological behaviour of the blends melt during processing was followed by measuring torque; extrusion capacity output and melts back‐pressure in a twin screw extruder. The processing parameters were decreased with the HDPE content. The results show that SEBS compatibilizer can yield compatibilization by substantially reducing torque and increasing the back‐pressure. However, the Hurst indices of melt processing parameters are increased with compatibilization. Near‐infrared spectra had been described by the Hurst index HNIR which is then related to HDPE content in the blends. The correlation between the blend compositions, morphological structure, mechanical and rheological properties and processing parameters was established and discussed on base of correlation with the fractal indices obtained from the SEM microphotographs of PS/HDPE/SEBS blends.
A New Green Thermoplastic Polymer with Improved Hydrophobic Character
Authors: Gopalakrishnan Preetha , Enqvist Evelina , Wallstrom Lennart , Gattin Richard , Saiter Jean Marc 
Published: March 2010

AbstractSummary: A green thermoplastic polymer based on wheat flour was modified by the addition of a natural crosslinker genipin. Films of the polymer modified with different composition of genipin were prepared by extrusion. Free surface energy using contact angle method, moisture absorption test and hardness test were used to characterize the products. From moisture absorption and contact angle measurements, it was seen that for genipin amounts higher than 0.2% w/w, a hydrophobic character is achieved. Results obtained indicate enhancement in hydrophobic properties of the films.
Preparation, Characterization and Application of Modified Surfaces with 3,5‐Bis(3,5‐dinitrobenzoyl‐amino) benzoic acid
Authors: Paez Julieta I. , Cappelletti Ariel L. , Baruzzi Ana M. , Brunetti Verónica , Strumia Miriam C. 
Published: March 2010

AbstractSummary: The spontaneous adsorption of the dendron 3,5‐Bis (3,5‐dinitrobenzoylamino) benzoic acid (D‐NO2) onto gold and carbon electrodes produced conductive surfaces with electroactive chemical functions. A comparative electrochemical behavior of both electrodes after dendron immobilization led us to conclude that the self‐assembly of D‐NO2 on carbon is faster and stronger. Considering this advantage, the surface of magnetic maghemite nanoparticles (MNPs) was modified using D‐NO2. Firstly, MNPs were modified with APS as silane coupling agent and afterwards, D‐NO2 was covalently attached to the surface, achieving nitro‐functionalized MNPs. Subsequently, the immobilization of these modified MNPs onto glassy carbon surfaces was explored to generate a novel platform promising for biosensors development.
Liquid Crystalline Organisation and Reaction Rate in the Formation of Liquid Crystal Thermoset Networks from Diepoxides and Dicyanates
Authors: Mormann Werner , Kuckertz Christian , Bröcher Markus 
Published: March 2010

AbstractSummary: The influence of the type of mesophase on the rate of reaction in amine curing or anionic polymerisation of mesogenic diepoxides, and in the cyclotrimerisation of mesogenic dicyanates has been investigated by isothermal DSC and IR‐spectroscopy. Epoxide/amine systems were found to react faster in the nematic than in the isotropic phase. Anionic polymerisation of epoxides is an example where increase of the reaction rate occurs with the transition from a mesophase of higher order (smectic) to phases with lower order (nematic, isotropic). For triaromatic dicyanates with one or three methyl groups at the central ring cyclotrimerisation is faster in the isotropic than in the nematic phase showing an increase of activation energy in the nematic phase with the number of methyl groups. A pronounced rate increase has been observed in the smectic phase as compared to the nematic phase for the unsubstituted triaromatic dicyanate. In this case activation energies in the two phases are comparable with those of non liquid crystalline dicyanates.
Studies on Boron Containing Poly(urethane fattyamide)
Authors: Zafar Fahmina , Kashif Mohammad , Sharmin Eram , Ahmad Sharif 
Published: March 2010

AbstractSummary: An attempt has been made to synthesize boron containing poly (urethane‐fattyamide) [B‐PUPGFA] through the incorporation of boron in the backbone of non drying oil such as Pongamia glabra oil derived poly (urethane‐fattyamide). The synthesis route involves 50% reduction in the use of harmful volatile organic contents [VOCs] and was carried out in situ by condensation reaction between N, N′‐bis (2‐hydroxyethyl) Pongamia glabra fattyamide and boric acid without solvent followed by the addition polymerization with toluene diisocyanate in minimum solvent. Spectral (FTIR, 1H‐NMR and 13C‐NMR), physico‐chemical, physico‐mechanical and chemical resistance of B‐PUPGFA was carried out by standard laboratory methods. The antibacterial performance of B‐PUPGFA was done by agar diffusion method against E. coli and S. aureus. The aforementioned performance of B‐PUPGFA was compared with Pongamia glabra oil based virgin poly (urethane‐fattyamide) [PUPGFA]. It is observed that the incorporation of boron has a significant influence on the overall performance of B‐PUPGFA film, which shows antibacterial activity against E. coli and S. aureus. Therefore, B‐PUPGFA serves as novel and promising biomaterial candidate for use as anticorrosive and antibacterial coating material.
Assessment of Mass Transport through Polymeric Electrolyte Membrane by Means of Potentiometric Measures
Authors: Gonçalves M. S. S. , Gomes A. S. 
Published: March 2010

AbstractSummary: This work aims to present a simple methodology to evaluate the proton transport of polymeric electrolyte membranes for fuel cells (PEMFC). The device consists of two ‘L’ tubes with a flanged edge, jointed by a metallic union that allows changing the different membranes to be analyzed. Through Fick´s equations, the matter that flows through the membrane can be assessed. For instance, a composite membrane made of SPSU containing TPA and modified with bis‐benzimidazole derivatives as cross‐linker showed flux and diffusion coefficient of 2.27.10−12 gm−2 s−1 and 2.18.10−7 m2 s−1, respectively. These results are 65% larger than the SPSU membranes. The device also allows visualizing, for instance, that the difference between the water columns under atmospheric pressure is not levelled; which means that the pore diameters are sufficiently small to hinder the water molecules crosses them. The conductance values have been found 10−3 S and 10−4 S to composite membrane and sulfonated membrane, respectively, while the Nafion® membrane presented value at same order of composite membrane.
Biodegradable Materials from Agro‐Based By‐Products
Authors: Terrié Caroline , Dobircau Larisa , Gopalakrishnan Preetha , Galandon Antoine , Saiah Redouan , Gattin Richard , Leblanc Nathalie , Saiter Jean Marc 
Published: March 2010

AbstractSummary: A new biodegradable thermoplastic material based on a wheat flour by‐product has been developed. The influence of various additives (glycerol, silica) and fibers (flax, cotton, hemp) on the mechanical properties of the material has been investigated. The development of expanded materials is also presented.
Thermal and Structural Behavior of Palm Oil. Influence of Cooling Rate on Fat Crystallization
Authors: Vuillequez Anaïs , Koza Lucy , Youssef Boulos , Bridier Mathilde , Saiter Jean Marc 
Published: March 2010

AbstractSummary: The effects of scanning rates (q = −0.5 °C/min to −50 °C/min) on the formation of the different phases occurring at low temperature of a palm oil are investigated by means of calorimetry and optical analysis. It is demonstrated that the cooling rates changed the polymorphism of triacylglycerols (TAGs). The centrifugation is used to separate the two fractions (olein and stearin) of palm oil. We show whereas the rate of centrifugation the separation is not effective. We obtained two fractions, a liquid fraction and a solid fraction which contains some liquid TAGs. It is observed that the solid fraction of palm oil is more sensitive to the effects of the cooling rates. By changing the cooling rate q, it appears threshold behaviour for q = −3 °C/min dividing the data discussion in two parts: for slow cooling rate and for fast cooling rate. At slow cooling rates, TAGs had more time to interact. Contrary at fast cooling rate, TAGs have not the time to be reorganised in more stable conformation. Micrographs revealed that the types of crystals observed were spherolites but some variations in crystal size appeared with the variation of cooling rate.
Model for the analysis of enzymatic proton‐transfer reactions with an application to soybean lipoxygenase‐1 and six mutants
Authors: Siebrand Willem , Smedarchina Zorka 
Published: March 2010

AbstractA general analytical model is introduced for the analysis of temperature‐dependent rate constants in enzymatic hydrogen and deuterium transfer reactions. It exploits the relationship between kinetic isotope effects (KIEs) and their temperature dependence in tunneling reaction to derive criteria that indicate whether a data set can be assigned to one rate‐determining tunneling step in the enzymatic reaction sequence. If so, the model evaluates the relative contributions of the tunneling mode and supporting skeletal modes to transfer and provides information on these modes. Recently reported kinetic data on proton transfer in linoleic acid catalyzed by soybean lipoxygenase‐1 (SLO1) and six mutants are analyzed by the model, which includes two oscillators, one representing proton motion relative to the skeletal framework and the other the supporting framework motions. It is concluded that most but not all components of this data set can be assigned to a single tunneling step, possible exceptions being associated with the highest observed rates, in agreement with evolutionary expectations. This still allows a complete analysis, namely in terms of the deuteron rate constants. The analysis evaluates how the contributions to proton transfer of the two modes and the electronic term depend on transfer distances in the enzyme and its mutants. It also provides rationalizations for several apparent anomalies, such as the vanishing of the activation energy for some mutants and the observed invariance of the KIE among mutants with very different activity. Copyright © 2010 John Wiley & Sons, Ltd.
Do men and their wives see it the same way? Congruence within couples during the first year of prostate cancer
Authors: Ezer Hélène , Chachamovich Juliana L. Rigol , Chachamovich Eduardo 
Published: March 2010

AbstractObjective: The purpose of this study was to determine the psychosocial adjustment congruence within couples through the first year of prostate cancer experience, and to explore the personal variables that could predict congruence within couples.Method: Eighty‐one couples were interviewed at the time of diagnosis; 69 participated at 3 months and 61 at 12 months. Paired t‐tests were used to examine dyadic congruence on seven domains of psychosocial adjustment. Repeated Measures ANOVAs were used to examine the congruence over time. Multiple regressions were used to determine whether mood disturbance, urinary and sexual bother, sense of coherence, and social support were predictors of congruence within couples on each of the adjustment domains.Results: At time 1, couples had incongruent perceptions in 3 of 7 domains: health care, psychological, and social adjustment. Three months later, health care, psychological, and sexual domains showed incongruence within couples. One year after the diagnosis, there were incongruent perceptions only in sexual and psychological domains. There was little variation of the congruence within couples over time. Husbands and wives' mood disturbance, urinary and sexual bother, sense of coherence, and social support accounted for 25–63% of variance in couple congruence in the adjustment domains in the study periods.Conclusion: The findings suggested that there is couple congruence. Domains in which incongruence was observed are important targets for clinical interventions. Greater attention needs to be directed to assisting couples to recognize the differences between their perceptions, especially the ones related to the sexual symptoms and psychological distress. Copyright © 2010 John Wiley & Sons, Ltd.
Characterizations and validations of novel antibodies toward translational research
Authors: Williams Reginald , Chung Joon‐Yong , Ylaya Kris , Whiteley Gordon , Hewitt Stephen M. 
Published: March 2010

AbstractPurpose: There is significant need for well‐characterized antibodies to the spectrum of human proteins encoded by the genome. Advances in tissue‐based proteomic profiling have led to the discovery of many candidate molecular biomarkers and therapeutic targets for which development of clinical assays is depending on high quality antibodies. We developed an antibody validation approach for screening of new mAbs.Experimental design: We utilized a multi‐stage approach of protein array and immunohistochemistry. In the first phase, we screened the NCI60 panel of cell lines by means of protein array and select antibodies based on concordance of mRNA expression to protein array signal. Results of this assay are used to predict antibody titer for immunohistochemistry on the NCI60 cell lines, presented as a tissue microarray. In the final stage, we created a tissue‐based protein expression map by performing immunohistochemistry on a multi‐tumor tissue microarray.Results: The success rate of this systematic antibody‐screening tool was approximately 93% as measured by the results from the protein array. Data from the NCI60 protein array could be used to predict antibody titer for immunohistochemistry, improving the success rate of immunohistochemical assay development.Conclusions and clinical relevance: The presented strategy of antibody validation and characterization can be provided a new tool for exploration of human proteome.
CYP17 polymorphisms and prostate cancer outcomes
Authors: Wright Jonathan L. , Kwon Erika M. , Lin Daniel W. , Kolb Suzanne , Koopmeiners Joseph S. , Feng Ziding , Ostrander Elaine A. , Stanford Janet L. 
Published: March 2010

AbstractOBJECTIVECytochrome P450 17α‐hydroxylases‐C‐17,20‐lyase (CYP17) is a key enzyme involved with the androgen biosynthesis pathway and has recently been targeted for therapy in men with advanced prostate cancer (PCa). However, studies relating prostate cancer outcomes with CYP17 gene variants have conflicting results. In this study we analyzed Single Nucleotide Polymorphisms (SNPs) spanning the CYP17 gene for association with PCa survival.METHODSThe cohort was comprised of Caucasian men, aged 40–64, diagnosed with PCa between 1993 and 1996 in King County, Washington who participated in a population‐based case–control study. CYP17 SNPs were selected to capture variation across the gene and known regulatory regions. PCa‐specific mortality (PCSM) was obtained by linking to the SEER cancer registry. Recurrence/progression of PCa was determined from patient survey data and medical records. Cox proportional hazards regression analysis was used to generate hazard ratios for patient outcomes.RESULTSGenotypes were available for 598 cases. With a median follow‐up of 13.2 years, 44 PCa deaths were observed. Recurrence/progression events were observed in 30% of subjects. No genetic association with disease progression were identified. However, men with the variant A allele in rs10883783 had a 56% risk reduction in PCSM (HR 0.44, 95% CI 0.21–0.98).CONCLUSIONThese data suggest that genetic variation in the CYP17 gene in Caucasian men is associated with PCa survival. Prostate 70: 1094–1101, 2010. © 2010 Wiley‐Liss, Inc.
Combined inhibitory effects of soy isoflavones and curcumin on the production of prostate‐specific antigen
Authors: Ide Hisamitsu , Tokiwa Shino , Sakamaki Kentaro , Nishio Koujiro , Isotani Shuji , Muto Satoru , Hama Takanori , Masuda Hiroko , Horie Shigeo 
Published: March 2010

AbstractBACKGROUNDSustained chronic inflammation in the prostate promotes prostate carcinogenesis. Since an elevated level of prostate‐specific antigen (PSA) per se reflects the presence of inflammation in the prostate, intervention to improve the PSA value might potentially have beneficial effects for the prevention of the development of prostate cancer. Isoflavones and curcumin have anti‐inflammatory and anti‐oxidant properties. We examined the biological effects of soy isoflavones and curcumin on LNCaP cells. After that, we conducted a clinical trial for men who received prostate biopsies, but were not found to have prostate cancer, to evaluate the effects of soy isoflavones and curcumin on serum PSA levels.METHODSThe expression of androgen receptor and PSA were examined in LNCaP cells before and after treatment of isoflavones and/or curcumin. Eighty‐five participants were randomized to take a supplement containing isoflavones and curcumin or placebo daily in a double‐blind study. Subjects were subdivided by the cut‐off of their baseline PSA value at 10 µg/ml. We evaluated values of PSA before and 6 months after treatment.RESULTSThe production of PSA were markedly decreased by the combined treatment of isoflavones and curcumin in prostate cancer cell line, LNCaP. The expression of the androgen receptor was also suppressed by the treatment. In clinical trials, PSA levels decreased in the patients group with PSA ≥ 10 treated with supplement containing isoflavones and curcumin (P = 0.01).CONCLUSIONSOur results indicated that isoflavones and curcumin could modulate serum PSA levels. Curcumin presumably synergizes with isoflavones to suppress PSA production in prostate cells through the anti‐androgen effects. Prostate 70: 1127–1133, 2010. © 2010 Wiley‐Liss, Inc.