bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does cognitive–behavioral therapy for PTSD improve perceived health and sleep impairment?
Authors: Galovski Tara E. , Monson Candice , Bruce Steven E. , Resick Patricia A. 
Published: May 2009

AbstractThere is a paucity of empirical study about the effects of evidence‐based psychotherapy for posttraumatic stress disorder (PTSD) on concurrent health concerns including sleep impairment. This study compares the differential effects of cognitive processing therapy (CPT) and prolonged exposure (PE) on health‐related concerns and sleep impairment within a PTSD sample of female, adult rape survivors (N = 108). Results showed that participants in both treatments reported lower health‐related concerns over treatment and follow‐up, but there were relatively more improvements in the CPT condition. Examination of sleep quality indicated significant improvement in both CPT and PE across treatment and follow‐up and no significant differences between treatments. These results are discussed with regard to the different mechanisms thought to underlie the treatments and future innovations in PTSD treatment.
Harmonic oscillations in a polymerization
Authors: Katime Issa , Ortiz Juan A. Pérez , Mendizábal Eduardo , Zuluaga Fabio 
Published: May 2009

AbstractA simple radical polymerization is proposed in this paper, with step‐by‐step chain growth (Ri + M → Ri+1), and termination by transfer to a third body (Ri + S → polymer) such as the solvent. It is assumed that, for a certain critical degree of polymerization n, the propagator Rn reacts with substrate H to produce a deactivator (V) of the first propagator (H + Rn → Rn + V; V + R1 → P1) R1. Assuming that monomer, M, and precursor concentrations are constant, and assuming that the deactivator reaches fast a steady state, the resulting kinetic equations are formally linear, but they admit, perturbations rj(t) of the steady‐state concentrations of the propagators R1, R2, …, Rn, which are periodic functions of time. Even more, they can be purely sinusoidal functions (which have been called “harmonic,” in analogy to the solutions of the well‐known classical harmonic oscillator) with phase shift between perturbations rj(t) = Rj− (Rj)0 and rj+1(t) = Rj+1 − (Rj+1)0. Based on these periodic solutions and aiming to a model as simple as possible, a theoretical analysis is made, resulting in that the minimum value for n would be n = 3. Of course, these harmonic oscillations “driven by trimer” are equally found in the group of all the remaining propagators with polymerization degree higher than 3 (variable Y = ∑ Rj). © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 507–511, 2009
Synthesis of polyetherols with isocyanuric ring. Kinetics and mechanisms of reactions, part 2: Consecutive reaction of ethylene carbonate with isocyanuric acid
Authors: Lubczak Jacek , Węglowska Elwira 
Published: May 2009

AbstractThe kinetics and mechanism of the reaction between isocyanuric acid and ethylene carbonate was studied. The multistep reaction in the presence of potassium carbonate as catalyst leads to polyetherols. The imide and hydroxyl groups of intermediates react with ethylene carbonate by slightly different mechanism and kinetics. The rate constants for these elementary processes were established, and based on these experimental data the mechanism of reaction was proposed. Using the isocyanuric acid and 1,3,5‐tris(2‐hydroxyethyl)isocyanurate, it has been found that the reaction of ethylene carbonate with intermediates occurs via a mixed mechanism. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 523–531, 2009
Current advances in sunflower oil and its applications
Authors: Garcés Rafael , Martínez‐Force Enrique , Salas Joaquín J. , Venegas‐Calerón Mónica 
Published: May 2009

AbstractThe fatty acid and triacylglycerol composition of a vegetable oil determine its physical, chemical and nutritional properties. The applications of a specific oil depend mainly on its fatty acid composition and the way in which fatty acids are arranged in the glycerol backbone. Minor components, e. g. tocopherols, also modify oil properties such as thermo‐oxidative resistance. Sunflower seed commodity oils predominantly contain linoleic and oleic fatty acids with lower content of palmitic and stearic acids. High‐oleic sunflower oil, which can be considered as a commodity oil, has oleic acid up to around 90%. Additionally, new sunflower varieties with different fatty acids and tocopherols compositions have been selected. Due to these modifications sunflower oils possess new properties and are better adapted for direct home consumption, for the food industry, and for non‐food applications such as biolubricants and biodiesel production.
Development of organic light‐emitting diodes for electro‐optical integrated devices
Authors: Ohmori Y. 
Published: May 2009

AbstractOrganic light‐emitting diodes (OLEDs) are discussed for electro‐optical integrated devices that are used for optical signal transmission. Organic optical devices including polymeric optical fibers are used for optical communication applications to realize polymeric electro‐optical integrated devices. The OLEDs were fabricated by vacuum process, i.e. the organic molecular beam deposition (OMBD) technique or a solution process on a polymeric or a glass substrate, for comparison. Optical signals faster than 100 MHz have been created by applying pulsed voltage directly to the OLED utilizing rubrene doped in 8‐hydoxyquinolinum aluminum (Alq3), as an emissive layer. OLEDs fabricated by solution process utilizing rubrene doped in carrier‐transporting materials have also discussed. OLEDs utilizing polymeric materials by solution process are also fabricated and discussed. Moving‐picture signals are transmitted utilizing both vacuum‐ and solution‐processed OLEDs, respectively.
Adhesion of Human U937 Monocytes to Nitrogen‐Rich Organic Thin Films: Novel Insights into the Mechanism of Cellular Adhesion
Authors: Girard‐Lauriault Pierre‐Luc , Truica‐Marasescu Florina , Petit Alain , Wang Hong T. , Desjardins Patrick , Antoniou John , Mwale Fackson , Wertheimer Michael R. 
Published: May 2009

AbstractWe present a two‐fold study designed to elucidate the adhesion mechanism of human U937 monocytes on novel N‐rich thin films deposited by plasma‐ and VUV photo‐polymerisation, so‐called “PVP:N” materials. It is shown that there exist sharply‐defined (“critical”) surface‐chemical conditions that are necessary to induce cell adhesion. By comparing the film chemistries at the “critical” conditions, we demonstrate the dominant role of primary amines in the cell adhesion mechanism. Quantitative real‐time RT‐PCR experiments using U937 cells that had adhered to PVP:N materials for up to 24 h are presented. The adhesion induces a transient expression of cytokines, markers of macrophage activation, as well as a more sustained expression of PPARγ and ICAM‐I.magnified image
Covalent Immobilization of Subtilisin A onto Thin Films of Maleic Anhydride Copolymers
Authors: Tasso Mariana , Cordeiro Ana L. , Salchert Katrin , Werner Carsten 
Published: May 2009

AbstractEnzymes cleaving the biopolymer adhesives of fouling organisms are attracting attention for the prevention of biofouling. We report a versatile and robust method to confine the serine protease Subtilisin A (or Subtilisin Carlsberg) to surfaces to be protected against biofouling. The approach consists of the covalent immobilization of the protease onto maleic anhydride copolymer thin film coatings. High‐swelling poly(ethylene‐alt‐maleic anhydride) (PEMA) copolymer layers permitted significantly higher enzyme loadings and activities than compact poly(octadecene‐alt‐maleic anhydride) (POMA) films. Substantial fractions of the immobilized, active enzyme layers were found to be conserved upon storage in deionized water for several hours. Ongoing studies explore the potentialities of the developed bioactive coatings to reduce the adhesion of various fouling organisms.magnified image
Monodisperse, Temperature‐Sensitive Microgels Crosslinked by SiOSi Bonds
Authors: Zhang Jian‐Tao , Pan Chang‐Jiang , Keller Thomas , Bhat Rahila , Gottschaldt Michael , Schubert Ulrich S. , Jandt Klaus D. 
Published: May 2009

AbstractA series of novel temperature‐sensitive microgels were prepared through precipitation polymerization using MPTMS as the comonomer as well as the crosslinker. APS acted as the initiator to initiate the radical copolymerization of NIPAAm and MPTMS, at the same time, the acid environment resulting from the decomposition of APS catalyzed the hydrolysis/condensation of the siloxane groups to generate crosslinking points. The experimental results revealed that the microgels exhibited temperature sensitivity and the phase transition temperature was approximately 31 °C. An increase of SDS concentration or a decrease of MPTMS content resulted in a reduction of the final hydrodynamic diameters of the microgels.magnified image
Synthesis of Heterotelechelic Poly(ethylene glycol)‐block‐poly(succinimide) Possessing Both Acetal andTert‐Butoxycarbonyl‐amino Terminals with Narrow Molecular Weight Distribution
Authors: Nakanishi Masataka , Kataoka Kazunori 
Published: May 2009

AbstractA novel heterotelechelic linear block copolymer of poly(ethylene glycol) (PEG) and poly(succinimide) (PSI) possessing both acetal andtert‐butoxycarbonyl‐amino (Boc‐NH) terminals (Acetal‐PEG‐b‐PSI‐NH‐Boc) with a narrow molecular weight distribution (MWD) was successfully prepared by the nucleophilic attack of triethylamine (TEA) to the poly(β‐benzyl L‐aspartate) (PBLA) segment of Acetal‐PEG‐b‐PBLA‐NH‐Boc. Acetal‐PEG‐b‐PBLA‐NH‐Boc with MWD of 1.07 was prepared by living anionic ring‐opening polymerization ofβ‐benzyl L‐aspartateN‐carboxy‐anhydride withα‐acetal‐ω‐amino PEG as a macroinitiator, followed by Boc protection. The subsequent conversion of PBLA segment to PSI was successfully carried out by reacting with the catalytic amount of TEA. The characterization by1H NMR, GPC and IR demonstrates that the formation of poly(succinimide) proceeded completely without any remarkable side reactions. Acetal‐PEG‐b‐PSI‐NH‐Boc thus obtained may have a potential utility as a targetable drug carrier in the field of drug delivery system.
Preparation and Characterization of Polyesterurethane Metallopolymers Containing Transition Metal Ions
Authors: Moroi Gabriela‐Nicoleta 
Published: May 2009

AbstractSeveral series of metallopolymers (MP) were synthesized from a MDI‐based polyesterurethane and various transition metal ion species, namely, copper(II), manganese(II), cobalt(II), iron(III) and chromium(III). Each series of MP were prepared by using different initial molar ratios urethane groups/metal ions (U/M). MP were characterized in comparison with the parent polyurethane (PU) by atomic absorption spectrometry (AAS), UV‐vis absorption spectroscopy, FT‐IR spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and tensile testing. The transition metal ions form coordination complexes with polyurethane functional groups, the intermolecular complexation resulting in the crosslinking of polymer chains. As a consequence, modifications take place in the original structure of PU, e.g. hydrogen bonding and crystallinity of the hard‐segment domains. MP compared with PU present differences in viscoelastic and mechanical behaviors, which generally indicate the reinforcing effect of metal ions on the polyurethane matrix, as well in thermal stability. It was revealed that each transition metal ion has specific effects on the structure and properties of PU. The implications and mechanisms behind these observations are discussed.
Poly(3‐hexylthiophene)/Poly(methyl methacrylate) Core‐Shell Electrospun Fibers for Sensory Applications
Authors: Kuo Chi‐Ching , Wang Cheng‐Ting , Chen Wen‐Chang 
Published: May 2009

AbstractNew electrospun (ES) sensory fibers consisted of poly(methyl methacrylate) (PMMA) core and poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) shell were successfully prepared using a two‐fluid coaxial electrospinning process. Field‐emission scanning electron microscope (FE‐SEM) studies showed that the prepared ES fibers had diameters of 500–700 nm and worm‐like surface structure of P3HT on the fiber. Red emission fibers were exhibited from the laser confocal microscope. Upon exposed to air under light for two weeks, significant blue‐shifting on both absorption and luminescence spectra was found on the prepared ES fibers. It was probably due to the chain scission occurred in the P3HT and led to the reduced conjugated length. The sensitivity of the ES fibers was much better than that of the spin‐coated P3HT film from the comparison on the variation of photophysical properties. Besides, the EPR result indicated the formation of the P3HT · O2 charge transfer complex (CTC), leading to the fiber conductivity of 10−6 S/cm without an external doping. The present study demonstrates that conjugated polymer based ES core‐shell fibers may have potential applications for oxygen‐sensing devices.
Surfactant Effect on Energy Transfer between Cationic Conjugated Polymer and Dye‐Labeled Oligonucleotide
Authors: Pu Kan‐Yi , Zhan Ruoyu , Liu Bin 
Published: May 2009

AbstractWe report a convenient and effective method to enhance the signal output of dye‐labeled oligonucleotide sensitized by cationic conjugated polymers (CCP). Sodium dodecyl sulphate (SDS) is utilized to regulate the interaction between CCP and dye‐labeled single‐stranded DNA in order to reduce the dye self‐quenching within the CCP/DNA complexes. Improvement of CCP‐sensitized dye emissison in the presence of SDS relative to that in the absence of SDS is observed, which reveals the importance of reducing CCP charge density in improving the energy transfer from CCP to dye‐labeled probes.
Polymers with Tethered Anionic and Cationic Groups as Membranes for Fuel Cells
Authors: Hickner Michael A. , Tudryn Gregory J. , Alam Todd M. , Hibbs Michael R. , Fujimoto Cy H. 
Published: May 2009

AbstractIonic clustering, water binding, and ion conductivity were studied in polymers functionalized with sulfonic acid and quaternary ammonium hydroxide groups. Small‐angle x‐ray scattering showed that no clustering occurred in the quaternary ammonium containing anion exchange membranes, while evidence of ionic clusters was present in both sulfonated poly(phenylene) and in Nafion, a poly(perfluorosulfonic acid). Interestingly, the water self‐diffusion coefficients of the anion exchange membranes were generally greater than those observed for the sulfonated poly‐ (phenylene)s, and moreover, the water self diffusion coefficients in anion exchange membranes were not a strong function of diffusion time. The water binding behavior lead to increased normalized conductivity in anion exchange membranes as compared to proton exchange membranes at the highest ion exchange capacities.
Global and Local Structural Changes of Protein Unfolding
Authors: Shiu Ying‐Jen , Jeng U‐Ser , Lin Sheng‐Hsien 
Published: May 2009

AbstractSummery: In the mean‐field Ising model, the folding‐unfolding behavior of a protein is regarded as an ensemble of units reduced from, presumably, peptide bonds or amino acid residues. Units of similar thermodynamic properties are further classified into groups that are related to, for instance, α‐helices or β‐sheets. Units of the same group are assumed to unfold collectively, whereas those of different groups may undergo either sequential or coupled unfolding. The introduction of unfolding groups facilitates the description of non‐collective local structural changes experimentally observed via a multi‐group unfolding. We incorporate denaturants and temperature effects into the free energy expression of the protein upon dissolution in a specific environment at thermal equilibrium, and a model protein, cytochrome c, was examined. Results indicate that there are at least four unfolding groups induced unfolding of cytochrome c: two are related to the prosthetic heme group, whereas another two groups are α‐helices and global nearly group, which largely account for global changes in protein morphology. The extracted thermodynamic parameters, on the basis of the Ising model, can closely predict unfolding behaviors of the proteins in compounded denaturing environments.
Factors Inhibiting the Alkyl‐Branch Plasticization of Polyoxymethylene
Authors: Martin Ryan T. , Miller Stephen A. 
Published: May 2009

AbstractThe ability of an alkyl branch to depress the melting temperature in a polyoxymethylene chain is measurably less than that in a polyethylene chain. The factors that inhibit the alkyl‐branch plasticization of polyoxymethylene are considered by computational assessment of a series of model compounds at various levels of theory: DFT B3LYP 6‐31+G*, DFT B3LYP 6‐311++G**, MP2 cc‐pVTZ, T1, and G3(MP2). Intramolecular interactions—characterized as acetal CH···O hydrogen bonds—are surprisingly strong and likely encourage conformational regularity in the vicinity of the alkyl branches, allowing maintenance of the intermolecular chain‐chain interactions. The acetal CH···O hydrogen bonds in dimethylene glycol average to 2.65 kcal/mol while the non‐acetal CH···O interactions in 1,3‐propanediol are much weaker with an average of 0.34 kcal/mol (G3(MP2)). The related, classical OH···O hydrogen bond in ethylene glycol is found to be worth 2.12 kcal/mol. To describe this energetic ordering, an additional stabilizing anomeric effect is invoked for dimethylene glycol, a model for polyoxymethylene.
Shear‐Induced Phase Separation of Entangled Polymer Solutions: Formation of Optically Anisotropic Strings as Precursor Structures of Shish‐Kebab
Authors: Hashimoto Takeji , Murase Hiroki , Ohta Yasuo 
Published: May 2009

AbstractShear‐induced structures were investigated for both ultrahigh molecular weight atactic polystyrene (UHMWaPS) and linear polyethylene (UHMWPE) solutions, which were entangled but homogeneous without shear flow, as a function of shear rate ($\dot \gamma $) or time after a step‐up shear flow. For the PE solutions, the shear flow was imposed at 124 °C which is higher than the nominal melting temperature Tnm of the solution without shear flow. At sufficiently high shear rates both solutions commonly formed highly optically anisotropic string‐like structures which are composed of a series of phase‐separated domains interconnected by bundles of stretched chains and aligned along the flow direction. After cessation of the shear flow the string‐like structures completely disappeared in the UHMWaPS solution, recovering a homogeneous solution, while the UHMWPE solution exhibited shish‐kebab structure. The results reveal a new kinetic pathway for shish‐kebab formation for the entangled crystallizable solution sheared at T > Tnm which involves first formation of the phase‐separated string‐like domains and subsequent crystallization into shish from the bundles of stretched chain and then kebab in the demixed domains composed of essentially random coils.
Molecular‐Integrated Phospholipid Polymer Nanoparticles with Highly Biofunctionality
Authors: Matsuno Ryosuke , Ishihara Kazuhiko 
Published: May 2009

AbstractSurface modifications of nanoparticles with phospholipid polymers composed of 2‐methacryloyloxyethyl phosphorylcholine (MPC), are summarized. The MPC can be available for various polymerization methods such as conventional radical polymerization and living radical polymerization, and easily copolymerized with other vinyl compounds. The MPC polymers have been widely used as biocompatible coating and stabilizer for nanoparticles even when they are under biological environment. Additionally, for immobilization of biomolecules, such as antibody and enzyme, the MPC polymers having active ester group are applicable. These MPC polymers coated on the nanoparticles immobilize protein under mild condition and the protein maintained bioactivity well. Moreover, introduction of functional inorganic nanocrystals inside of the nanoparticles is effective to obtain good imaging tool for specific cells. The potential of molecular integration on nanoparticles based on MPC polymer chemistry will be expanded nanobiosensing, nanoimaging and nanodiagnostic system.
Novel Nanostructural Hybride Materials for Photodynamic Theraphy
Authors: Nowakowska Maria , Nawalany Kinga , Kępczyński Mariusz , Krawczyk Zdzisław 
Published: May 2009

AbstractPhotodynamic theraphy (PDT) is a clinically approved method for treatment of cancer and some other diseases. It employs the combination of a drug (photosensitizer) and light to induce photoxicity towards the cancerous cells. The efficiency of currently used photosensitizers is limited due to their aggregation in aqueous media and low chemical purity; usually a mixture of various isomers is used. This paper presents the results of our studies on the development of nanostructural materials for PDT. They are constructed from porphyrin (Po) which is covalently attached to the chain of hydrophylic polymer such as poly(methacrylic acid) (PMA) or poly(ethylene glycol) (PEG) and solubilized in lipid bilayer of liposome vesicles. The attachment of Po to the polymer chain improves its solubility in water while the solubilization in liposome carriers helps the dye to penetrate the cell membranes. Physicochemical and photophysical properties of those systems were determined. The in vitro studies on cancer cell lines demonstrated that the photosensitizers are efficiently accumulated in the cells. Their dark toxicity is negligible, while phototoxicity is very high.
Biodegradable Poly(3‐hydroxybutyrate) Nanocomposite
Authors: Ohashi Eiji , Drumond Walker Soares , Zane Nicholas Picoli , de Faria Barros Pedro Wang , Lachtermacher Marly Grinapel , Wiebeck Hélio , Wang Shu Hui 
Published: May 2009

AbstractThis work seeks bringing a technological and social contribution by searching blends and composites of poly(3‐hydroxybutyrate) (PHB) and polyethylene widely used in packaging films, and colloidal silica. The mixtures were prepared by extrusion using a single‐screw extruder and were analyzed regarding their thermal and mechanical properties and morphology. The results have shown PHB toughness in the studied compositions, which elongation at break was in the range 5–80% compared to 2% for neat PHB. The small amount (0.2 to 0.4%) of added silica seemed to increase in 20% the tensile strength. The thermal degradation by thermogravimetry from room temperature to 800 °C revealed a mixed behavior for the composites between PHB and polyethylene.
Synthesis and Characterization of Chitosan/ Dextran‐Based Hydrogels for Surgical Use
Authors: Liu G. , Shi Z. , Kuriger T. , Hanton L.R. , Simpson J. , Moratti S.C. , Robinson B.H. , Athanasiadis T. , Valentine R. , Wormald P.J. , Robinson S. 
Published: May 2009

AbstractA series of hydrogels were formed from the reaction between an amine functionalized succinyl chitosan and an oxidized dextran. The properties and rate of formation of the gel were related to both the amine and aldehyde levels of the precursors. These levels could be readily changed by altering the reaction conditions, and allowed good control of the gel properties. Oxidation of the dextran with periodate was accompanied by chain scission and a large reduction in molecular weight. The gel showed excellent haemostatic properties and reduction of adhesions in animal models.
Supramolecular Mobility in Polyrotaxanes Exploits Biomedical Functions
Authors: Yui Nobuhiko 
Published: May 2009

AbstractThe mobility of cyclodextrins (CDs) threaded onto a linear polymeric chain and the dethreading of the CDs from the chain are the most fascinating features seen in polyrotaxanes. These structural characteristics are very promising to their possible applications in biomedical use. Enhancing multivalent interaction between ligand‐receptor systems by using ligand‐polyrotaxane conjugates is one of the excellent properties related to the CD mobility. Gene delivery using cytocleavable polyrotaxanes is more practical but highly crucial in drug delivery. Such a supramolecular approach using CD‐containing polyrotaxanes is extensively expected to exploit a new paradigm of advanced biomaterials for future medicines.