bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extending fragment‐based free energy calculations with library monte carlo simulation: Annealing in interaction space
Authors: Lettieri Steven , Mamonov Artem B. , Zuckerman Daniel M. 
Published: November 2010

AbstractPre‐calculated libraries of molecular fragment configurations have previously been used as a basis for both equilibrium sampling (via library‐based Monte Carlo) and for obtaining absolute free energies using a polymer‐growth formalism. Here, we combine the two approaches to extend the size of systems for which free energies can be calculated. We study a series of all‐atom poly‐alanine systems in a simple dielectric solvent and find that precise free energies can be obtained rapidly. For instance, for 12 residues, less than an hour of single‐processor time is required. The combined approach is formally equivalent to the annealed importance sampling algorithm; instead of annealing by decreasing temperature, however, interactions among fragments are gradually added as the molecule is grown. We discuss implications for future binding affinity calculations in which a ligand is grown into a binding site. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
The preparation of [pentane‐5,5,5‐3H3]‐abnormal‐cannabidiol
Authors: Byard Stephen J. , Carr Steven A. , DeFaria Jose F. , Filer Crist N. , Herbert John M. , Forcada Tatiana Jaramillo 
Published: November 2010

AbstractA bromoalkane precursor was synthesized in six steps, and its copper catalysed coupling with methylmagnesium chloride to provide unlabelled abnormal‐cannabidiol (1a) was optimized. The methodology was used for an analogous coupling using [3H3]‐methylmagnesium iodide to provide [pentane‐2H3]‐abnormal‐cannabidiol (1b). Copyright © 2010 John Wiley & Sons, Ltd.
Physiological predictors of posttraumatic stress disorder
Authors: Gutner Cassidy A. , Pineles Suzanne L. , Griffin Michael G. , Bauer Margaret R. , Weierich Mariann R. , Resick Patricia A. 
Published: November 2010

AbstractStudies have assessed relationships between posttraumatic stress disorder (PTSD) symptoms and physiological reactivity concurrently; fewer have assessed these relationships longitudinally. This study tests concurrent and prospective relationships between physiological reactivity (heart rate and skin conductance) to a monologue procedure and PTSD symptoms in female assault survivors, tested within 1 and 3 months posttrauma. After controlling for initial PTSD and peritraumatic dissociation, 3 measures of increased physiological reactivity to the trauma monologue at 1 month predicted 3‐month PTSD reexperiencing severity. Additionally, increased heart rate following trauma and neutral monologues at 1 month was predictive of 3‐month numbing symptoms. Implications for the prospective relationship between physiological reactivity to trauma cues and PTSD over time are discussed.
Attention to process and clinical outcomes of implementing a rural school‐based trauma treatment program
Authors: Hansel Tonya Cross , Osofsky Howard J. , Osofsky Joy D. , Costa Richard N. , Kronenberg Mindy E. , Selby Marian L. 
Published: November 2010

AbstractThe Louisiana Rural Trauma Services Center was established to provide, improve, and enhance urgently needed assessment, treatment, crisis management, and consultation services for children and adolescents exposed to traumatic events in three rural southeastern Louisiana parishes. The purpose of this study is to describe the process of implementing the rural school‐based trauma treatment program and to evaluate its effectiveness in 115 students. Through attention to process including the three‐tiered approach of relationship building, trauma training, and trauma services, the school‐based trauma treatment program proved effective in reducing trauma symptoms. This study is important to support the widespread implementation of school‐based mental health services.
Nanoparticle Vesicles Through Self Assembly of Cyclodextrin‐ and Adamantyl‐Modified Silica
Authors: Isenbügel Kathrin , Ritter Helmut , Branscheid Robert , Kolb Ute 
Published: November 2010

AbstractStable nanoparticle vesicles were for the first time prepared from adamantyl‐ and cyclodextrin (CD)‐modified silica nanoparticles forming host–guest interactions in aqueous solution. Adamantyl‐functionalized nanoparticles were obtained from thiol‐isocyanate reaction of thiol‐modified nanoparticles with 1‐adamantyl isocyanate. The CD modified silica particles were isolated from a reaction of mono‐6‐para‐toluenesulfonyl‐β‐cyclodextrin with the thiol functionalized silica under microwave conditions in basic media. The obtained particles were characterized in respect of agglomeration and self‐assembly behavior in aqueous solution by dynamic light scattering and transmission electron microscopy. The found vesicle structures are exceptionally stable even after evaporation of water. Such inorganic hollow spheres formed through self‐assembly processes may be important for chemical storage and transport. The technique of chemically‐driven assembly is an attractive option to form useful complex structures by tunable agglomeration. magnified image
Novel Supports for Ethylene Polymerisation Based on Polystyrene Polymers
Authors: Tudella Joana , Ribeiro M. Rosário , Cramail Henri , Deffieux Alain 
Published: November 2010

AbstractThe industrial use of metallocene/methylaluminoxane catalytic systems and late transition metal catalysts requires the use of supports to directly get polyethylene (PE) with spherical morphology. The presence of residues of the inorganic support gives rise to PE contamination problems, therefore less contaminating organic supports may present an interesting alternative. In this work, linear hydroxypolystyrene (PS‐OH) and polystyrene‐block‐isoprene copolymer (PS‐b‐PI) were tested as supports for ethylene polymerisation. The ability of these polymers when dissolved in a selective solvent to form micelles or aggregates, was investigated by light scattering techniques. Next, their capacity to act as MAO or TMA‐activated supports towards MeDIP(2,6‐iPrPh2FeCl2) catalyst was analysed by carrying ethylene polymerisation tests and PE morphology studies. The PS‐b‐PI copolymer, used as organic support in heptane, enabled the obtention of PE with well defined spherical morphology.
Successive Synthesis of Well‐Defined Star‐Branched Polymers by “Convergent” Iterative Methodology Using Core‐Functionalized 3‐Arm Star‐Branched Polymer and a Specially Designed 1,1‐Diphenylethylene Derivative
Authors: Higashihara Tomoya , Inoue Kyoichi , Hirao Akira 
Published: November 2010

AbstractThe synthesis of well‐defined regular and miktoarm star‐branched polymers by a convergent iterative methodology using core‐functionalized 3‐arm star‐branched polymer with 1,1‐diphenylethylene (DPE) moiety and a specially designed DPE derivative is described. The methodology involves the following two reaction steps in the entire iterative synthetic sequence: 1) a coupling reaction of a star‐branched polymer having an anion at the core with a DPE derivative with two benzyl bromide moieties, 1‐{4‐[5,5‐bis(3‐bromomethylphenyl)‐7‐methylnonyl]phenyl}‐1‐phenylethylene, and 2) an addition reaction of the resulting core‐DPE‐functionalized star‐branched polymer with sec‐BuLi to convert the DPE moiety to a DPE‐derived anion. The iterative synthetic sequence including these two reaction steps, 1) and 2), was repeated to successively synthesize star‐branched polymers with more arms. Iteration of this synthetic sequence doubled the number of the arms in the star‐branched polymer. With this methodology, 6‐arm, 12‐arm, and 14‐arm regular star‐branched polystyrenes as well as 6‐arm A2B2C2, A4B2, and 12‐arm A4B4C4 and A8B4 miktoarm star‐branched polymers with well‐defined structures have been successfully synthesized.
Modification of Chemically Amplified Resists by Radical Copolymerization
Authors: Bulgakova S. , Johns M. , Kiseleva E. 
Published: November 2010

AbstractModification of a phenolic resist has been carried out by copolymerization with methacrylic monomers. Influence of irradiation source and its intensity has been studied by analyzing sensitive curves of a various resist composition. Inversion of imaging type at varying post exposure bake temperature has been investigated for resists based on copolymers containing methacrylic acid units, which has been related with crosslinking of macromolecules.
Investigating Acrylic Acid Polymerization by Using a Droplet‐Based Millifluidics Approach
Authors: Lorber Nicolas , Pavageau Bertrand , Mignard Emmanuel 
Published: November 2010

AbstractWe present herein the basic concept of droplet‐based millifluidics as an original tool to monitor polymerization kinetics. As a proof of concept, we use aqueous droplets of acrylic acid mixed with sodium persulfate at various pH as polymerization microreactor models. According to the pH and the temperature, completion could be obtained within a minute. Despite the fact that this reaction is quite fast and exothermic, we were able to acquire data in order to obtain valuable information about the polymerization kinetics. We were also able to estimate the overall activation energy for polymerization rate. Furthermore, offline analyses by Size Exclusion Chromatography show high molecular weights and high polydispersities. These results set the stage for further studies of polymerization reactions where detailed basic kinetic data must be acquired in conditions which cannot be investigated by using conventional batch glassware (i.e. high temperatures or concentrations). This new approach can also be used as an efficient High Throughput Screening tool.
Novel Supramolecular Hydrogels as Artificial Vitreous Substitutes
Authors: Lee‐Wang Hui Hui , Blakey Idriss , Chirila Traian V. , Peng Hui , Rasoul Firas , Whittaker Andrew K. , Dargaville Bronwin L. 
Published: November 2010

AbstractThe possibility of employing self‐healing gels as potential artificial vitreous substitutes is being explored. Advancement of traditional synthetic hydrogels as vitreous substitutes is hindered by their fragmentation upon injection into the vitreous cavity leading ultimately to inflammation. Preliminary work involved developing first generation self‐healing gels, using amphiphilic tri‐block copolymers of poly(propylene glycol)‐block‐poly(ethylene glycol)‐block‐poly(propylene glycol) (PPG‐PEG‐PPG) as the building block. Eight linear self‐healing gels are synthesized by tethering an ureidopyrimidinone system to synthetically modified PPG‐PEG‐PPG via the formation of a bis‐urea as a linker. The reversible nature of the hydrogen bonds permits alteration of their physical properties by changing the environment, yet retaining desirable characteristics. Despite low solubility in water, these polymers demonstrated associating behaviour under the investigated conditions, which is encouraging. Future generations of self‐healing gels should involve the selection of a more hydrophilic core and/or star‐like polymers to facilitate gel formation and strengthen the network.
Replication of Micro‐ and Nanostructures on Polymer Surfaces
Authors: Holzer Clemens , Gobrecht Jens , Schift Helmut , Solak Harun 
Published: November 2010

AbstractSummary: Via geometrical micro‐ and nanostructures new functionalities like controlled wetting properties, biological adhesive / dehesive properties or surface patterns for guided self assembly can be added to polymer surfaces. This is especially interesting for medical or biotechnological applications, because there is no new approval process necessary.The whole process from producing the structures via EUV‐interference lithography to the injection moulding will be shown. How far the limits for the smallness of these structures on polymers are already pushed forward show the results from our latest injection moulded samples. Grooves of 18 nm width ‐ this means world record! ‐ could be reproduced in an industrial process and in an economical very interesting high‐volume production.
Ferrocene Containing Polyimides as a Route to Low‐κ Dielectric Materials
Authors: Seçkin Turgay , Köytepe Süleyman , Kıvılcım Nilüfer 
Published: November 2010

AbstractPolyimides incorporating the ferrocene unit were prepared by in situ curing of poly (amic acid) macromolecules with ferrocene, for the molecular‐level design of low dielectric constant (low‐κ) materials. The effects of ferrocene on dielectric properties of polyimide are investigated in detail in this study. Ferrocene containing polyimides exhibit a number of desirable properties including low‐water absorption and admirable thermal stability. Systematic studies demonstrate that proper insertion of ferrocene into a polyimide backbone can give rise to a reduction in the material's dielectric constant. All composites were subjected to DSC measurements for the purpose of examining Tg from all composition. Scanning electron microscopy (SEM), X‐ray diffraction (XRD) and the other conventional techniques were used for structural characterization.
Synthesis of New Regioselectively Sulfated Hyaluronans for Biomedical Application
Authors: Becher Jana , Möller Stephanie , Weiss Dieter , Schiller Jürgen , Schnabelrauch Matthias 
Published: November 2010

AbstractSulfated glycosaminoglycans (GAGs) display various biological effects which are strongly influenced by the degree of sulfation and the position of sulfate groups within the polymer. Hyaluronan, a non‐sulfated GAG, represents a readily accessible educt to synthesize structural analogues of sulfated GAGs mimicking their biological activity. Different strategies were developed and evaluated to synthesize hyaluronan sulfates with a free primary hydroxyl group at C‐6' and sulfated secondary hydroxyl groups. Applying selective desulfation methods of high‐sulfated hyaluronan by means of silylating agents, products regioselectively desulfated at the primary C‐6' but also partly the C‐4' position were obtained. A pathway using benzoyl ester protecting groups to block the primary hydroxyl function of Hya during the sulfation resulted in a high‐sulfated product, functionalized only at the secondary hydroxyl groups.
Chitosan Macromolecules on a Substrate: Deposition from Solutions in sc CO2 and Reorganisation in Vapours
Authors: Khokhlova Marina A. , Chaschin Ivan S. , Grigorev Timofei E. , Gallyamov Marat O. 
Published: November 2010

AbstractSpecially pretreated chitosan macromolecules possess limited solubility in supercritical carbon dioxide. When deposited on mica substrate from such solutions they adopt somewhat extended conformation. The adsorbed macromolecules become mobile on the interface when exposed to water vapour as revealed by environmental scanning force microscopy. During the exposure in the presence of coadsorbed water layer the chitosan strands demonstrate slight tendency to adopt more compact but still two‐dimensional conformation on the substrate.
Effect of Bee Pollen on the Mechanical and Thermal Properties of Starch Films
Authors: Macieira Carles A. C. , Correia Suely J. P. , de Sousa Ana Paula Belizário , Júnior Ricardo L. C. Albuquerque , Araújo Yzila L. F. Maia , Melo Mateus S. , Costa Luiz P. , Cardoso Juliana C. , Padilha Francine F. 
Published: November 2010

AbstractThe use of casein, starch and bee pollen as biodegradable materials has been promise. The objective of this work was the development and characterization of films containing casein, pollen and starch. The films were obtained by casting process and the solvent evaporation was performed at 40 °C/24 h. The films characterization was carried out by microscopy, thermal analysis, opacity test, mechanical properties and barrier methods. The starch films presented heterogeneous on microscopy analysis. The thermal behaviors of pollen films were similar. The formulation containing only pollen 3% was unable to form film. The introduction of pollen in starch film formulation improved the mechanical characteristic and thermal stability of films.
QSAR Analysis Involving Assay Results Which are only Known to be Greater Than, or Less Than Some Cut‐off Limit
Authors: Lind Peter 
Published: November 2010

AbstractIt is often impossible to measure compound properties above or below some detection limit, or cut‐off level, in which cases result values can only be recorded as lying above or below that censoring limit. Such result values carry information, but are often excluded from QSAR studies or forcing the use of classification methods where regression models are more appropriate.This paper describes a regression method which makes use of censored values. The method works by estimating (imputing) the values underlying censored results. The algorithm was tested for stability and accuracy in the context of Free–Wilson R‐group activity score calculations.
Temperature‐dependent 11B spin–lattice relaxation time for BF4 and CF3BF3 anions in room‐temperature ionic liquids
Authors: Hayamizu Kikuko , Tsuzuki Seiji , Seki Shiro 
Published: November 2010

AbstractTemperature‐dependent 11B T1 values were measured for the BF4 anion and BF3 in the CF3BF3 anion in room‐temperature ionic liquids (RTILs) composed of the cation N‐diethyl‐N‐methyl‐N‐(2‐methoxyethyl)ammonium (DEME). Including the lithium‐salt‐doped samples, two neat and two binary ionic liquids were studied. Arrhenius plots of the 11B T1 showed T1 minima for BF4 in the temperature range between 243 (or above freezing) and 373 K. Using the Bloembergen, Pound, and Purcell(BPP) equations for the 11B quadrupolar and 11B19F dipolar relaxation mechanisms, the correlation times for motions of BF4 were calculated. Since the internal rotation of BF3 is assumed in CF3BF3, T1 minimum was not observed. The effects of the addition of the lithium salt on the 11B correlation time and 11BT1 for the anions in the ILs are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Intermolecular interaction studies using small volumes
Authors: Bourry David , Sinnaeve Davy , Gheysen Katelijne , Fritzinger Bernd , Vandenborre Gianni , Van Damme Els J. M. , Wieruszeski Jean‐Michel , Lippens Guy , Ampe Christophe , Martins José C. 
Published: November 2010

AbstractWe present the use of 1‐mm room‐temperature probe technology to perform intermolecular interaction studies using chemical shift perturbation methods and saturation transfer difference (STD) spectroscopy using small sample volumes. The use of a small sample volume (5–10 µl) allows for an alternative titration protocol where individual samples are prepared for each titration point, rather than the usual protocol used for a 5‐mm probe setup where the ligand is added consecutively to the solution containing the protein or host of interest. This allows for considerable economy in the consumption and cost of the protein and ligand amounts required for interaction studies. For titration experiments, the use of the 1‐mm setup consumes less than 10% of the ligand amount required using a 5‐mm setup. This is especially significant when complex ligands that are only available in limited quantities, typically because they are obtained from natural sources or through elaborate synthesis efforts, need to be investigated. While the use of smaller volumes does increase the measuring time, we demonstrate that the use of commercial small volume probes allows the study of interactions that would otherwise be impossible to address by NMR. Copyright © 2010 John Wiley & Sons, Ltd.
Photopolymerization behavior in nanocomposites formed with thiol–acrylate and polymerizable organoclays
Authors: Kim Soon Ki , Guymon C. Allan 
Published: November 2010

AbstractBecause of the inherent characteristics of the thiol–ene step growth mechanism in preparation of thiol–ene photopolymer clay nanocomposites, the ratio between thiol and ene functional groups at and near the organoclay surfaces may have a significant effect on the polymerization behavior. This study investigates the influence of monomer composition and the type of polymerizable organoclay on thiol–acrylate photopolymerization behavior in preparation of photocurable clay nanocomposite systems. To this end, two types of polymerizable organoclays with acrylate or thiol functional group on the clay surfaces were compared in monomer compositions with different polarity and functionality. Real‐time infrared spectroscopy was used to characterize polymerization behavior in conjunction with photo‐DSC. The degree of clay exfoliation was evaluated using small angle X‐ray scattering and correlated with photopolymerization behavior. Higher chemical compatibility of components induced enhanced clay exfoliation resulting in increase in photopolymerization rate. By affecting the stoichiometric ratio of functional groups in the clay gallery, thiolated organoclays enhance thiol–ene reaction, whereas acrylated organoclays encourage acrylate homopolymerization. In addition, inducing more propagating thiyl radicals on the organoclay surfaces by increasing functionality of thiol monomer also facilitates thiol–ene copolymerization, whereas the increase of acrylate functionality reduces final thiol conversion. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Dicarbonyl pentaphenylcyclopentadienyl iron complex for living radical polymerization: Smooth generation of real active catalysts collaborating with phosphine ligand
Authors: Ishio Muneki , Ouchi Makoto , Sawamoto Mitsuo 
Published: November 2010

AbstractWe achieved metal‐catalyzed living radical polymerization (LRP) through “unique” catalyst transformation of iron (Fe) complex in situ. A dicarbonyl iron complex bearing a pentaphenylcyclopentadiene [(CpPh)Fe(CO)2Br: CpPh = η‐C5Ph5] is too stable itself to catalyze LRP of methyl methacrylate (MMA) in conjunction with a bromide initiator [H‐(MMA)2‐Br]. However, an addition of catalytic amount of triphenylphosphine (PPh3) for the system led to a smooth consumption of MMA giving “controlled” polymers with narrow molecular weight distributions (∼90% conversion within 24 h; Mw/Mn = 1.2). FTIR and 31P NMR analyses of the complex in the model reaction with H‐(MMA)2‐Br and PPh3 demonstrated that the two carbonyl ligands were irreversibly eliminated and instead the added phosphine was ligated to give some phosphorous complexes. The ligand exchange was characteristic to the CpPh complex: the exchange was much smoother than other cyclopentadiene‐based complexes [i.e., CpFe(CO)2Br: Cp = C5H5; Cp*Fe(CO)2Br, Cp* = C5Me5]. The smooth transformation via the ligand exchange would certainly contribute to the controllability at the earlier stage in the polymerization as well as at the latter. The catalytic activity was enough high, as demonstrated by the successful monomer addition experiment and precise control even for higher molecular weight polymer (Mw/Mn < 1.2 under 1000‐mer condition). Such an in situ transformation from a stable complex would be advantageous to practical applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Proteomic analysis of acute kidney injury: Biomarkers to mechanisms
Authors: Bennett Michael R. , Devarajan Prasad 
Published: November 2010

AbstractAcute kidney injury (AKI) is a devastating clinical condition, both in terms of mortality and costs, and is occurring with increasing incidence. Despite better clinical care, the outcomes of AKI have changed little in the last 50 years. This lack of progress is due in part to a lack of early diagnostic biomarkers and a poor understanding of the disease mechanisms. This review will focus on the rapid progress being made in both the understanding of AKI and the promising panel of early biomarkers for AKI that have come out of both direct proteomic analysis of body fluids of AKI patients and more targeted proteomic approaches using clues from other methods such as transcriptomics. This review concludes with a discussion of the future of proteomics and personalized medicine in AKI and the challenges presented in translating these exciting proteomic results to the clinic.