bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman spectroscopy of topiramate under high pressure conditions
Authors: Sena Diniz M. , Freire Paulo T. C. , Filho Josué M. , Melo Francisco E. A. 
Published: September 2009

AbstractTopiramate is a white crystalline solid with powerful anticonvulsant activity and is used to treat epilepsy. Drug manufacturing involves various physical and chemical processes, which may lead to the formation of an unexpected, or undesired, crystalline phase, in a phenomenon known as polymorphism. In this paper, the behavior of topiramate crystal is studied under pressures up to 10.8 GPa using Raman spectroscopy. Under the conditions employed, Raman spectra from topiramate under pressure showed no strong evidence of a phase change, although amorphization may be considered. This may be accounted for by its crystal structure, comprising oppositely running chains of topiramate molecules linked by asymmetric hydrogen bonds, which pose a kinetic barrier against a structural change. It is not yet safe to rule out the existence of topiramate polymorphs, which could possibly be obtained under special crystallization conditions, but not after compression, at least up to 10 GPa. Copyright © 2009 John Wiley & Sons, Ltd.
Adjustment and control of SERS activity of metal substrates by pressure
Authors: Xia Lixin , Jia Yi , Liu Guangye , Yang Zhilin , Chen Xiaowei , Zhang Huili , Sun Mengtao 
Published: September 2009

AbstractMetal pellets of silver and copper for surface‐enhanced Raman scattering (SERS) spectroscopy were prepared by compression with different pressures. It was found that the SERS activity of the pellet could be controlled by pressure. Enhanced Raman scattering properties of the metal pellets in the presence of adsorbed 4‐mercaptobenzoic acid (4‐MBA) with excitation at 632.8 or 514 nm could be obtained by choosing proper pressure of pellatization. The SERS peak intensity of the band at ∼1584 cm−1 of 4‐MBA adsorbed on the metal pellets varies as a function of applied pressure, and which is about 1.2–32 times greater than when it is adsorbed on silver and copper particles. The calculated results of three‐dimensional finite‐difference time‐domain method (3D‐FDTD) are in good agreement with the experimental data. Moreover, no spurious peaks appear in the SERS spectra of the samples because no other chemicals are involved in the simple preparation process of the metal pellets, which will facilitate its use as an SERS‐active substrate for analytical purposes. In summary, SERS‐active metal pellets can be produced simply and cost effectively by the method reported here, and this method is expected to be utilized in the development of SERS‐based analytical devices. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of Well‐Defined Telechelic Macrophotoinitiator of Polystyrene by Combination of ATRP and Click Chemistry
Authors: Degirmenci Mustafa , Genli Nasrettin 
Published: September 2009

AbstractA new well‐defined telechelic macrophotoinitiator of polystyrene was synthesized by combination of ATRP and click chemistry. The ATRP of styrene by means of 2‐oxo‐1,2‐diphenylethyl‐2‐bromopropanoate (PI‐Br) initiator with CuBr/2,2′‐bipyridine yields polystyrene with photoactive benzoin (PI) and bromine (Br) group (PI‐PSt‐Br). Subsequently, PI‐PSt‐Br was converted to PI‐PSt‐N3 by simple nucleophilic substitution reaction. Alkyne functionalized benzoin (PI‐alkyne) was synthesized by using benzoin photoinitiator and propargyl bromide. Then the coupling reaction between PI‐PSt‐N3 and PI‐alkyne was performed by Cu(I) catalysis. The spectroscopic studies revealed that low‐polydispersity polystyrene with desired photoinitiator functionality at both end of the chain, PI‐PSt‐PI, was obtained.magnified image
Determining Initiator Efficiency in Radical Polymerization by Electrospray‐Ionization Mass Spectrometry
Authors: Buback Michael , Frauendorf Holm , Günzler Fabian , Huff Felix , Vana Philipp 
Published: September 2009

AbstractA method for measuring initiator efficiency in radical polymerization using ESI‐MS is presented. The method is based on the evaluation of relative MS peak intensities of polymer that has been initiated by a mixture of initiators, of which one serves as an internal reference. The method is quickly and easily performed and was found to be reproducible and robust. In polymerization of methyl methacrylate in solution, the efficiency of BTMHP at 80 °C was determined to be fBTMHP = 0.57 ± 0.08, and the efficiency of DBPO at 100 °C was measured to be fDBPO = 0.89 ± 0.08.magnified image
Synthesis and Characterization of Alternating and Random Copolymer Brushes
Authors: Ishizu Koji , Okamoto Nobuyuki , Murakami Takuya , Uchida Satoshi , Nojima Schuichi 
Published: September 2009

AbstractAlternating free‐radical copolymerization of vinylbenzyl‐ and methacryloyl‐terminated macromonomers in the presence of Lewis acid was applied to the synthesis of prototype copolymer brushes composed of polystyrene/poly(ethylene oxide) (PS/PEO) alternating structure. Random copolymer brushes were also prepared by radical copolymerization of both macromonomers in the absence of Lewis acid. It was found from dilute solution properties that both copolymer brushes composed of short aspect ratio formed an ellipsoid‐like single molecule in solution. To discuss the intramolecular phase separation of PS/PEO brushes in solution, we determined the radius of gyration (Rg) and cross‐sectional radius of gyration (Rg,c) of copolymer brushes by small‐angle X‐ray scattering (SAXS) using Guinier's plots in DMF and styrene. We used styrene as a solvent to cancel each other out with the electron density of PS side chains. We made also clear the effect of branching topology on polymer crystallinity to be examined by comparing the copolymer brushes with corresponding linear PEO or PEO‐block‐PS block copolymer.magnified image
Melt Dispersion and Electrospinning of Non‐Functionalized Multiwalled Carbon Nanotubes in Thermoplastic Polyurethane
Authors: Hunley Matthew T. , Pötschke Petra , Long Timothy E. 
Published: September 2009

AbstractNanoscale fibers with embedded, aligned, and percolated non‐functionalized multiwalled carbon nanotubes (MWCNTs) were fabricated through electrospinning dispersions based on melt‐compounded thermoplastic polyurethane/MWCNT nanocomposite, with up to 10 wt.‐% MWCNTs. Transmission electron microscopy indicated that the nanotubes were highly oriented and percolated throughout the fibers, even at high MWCNT concentrations. The coupling of efficient melt compounding with electrospinning eliminated the need for intensive surface functionalization or sonication of the MWCNTs, and the high aspect ratio as well as the electrical and mechanical properties of the nanotubes were retained. This method provides a more efficient technique to generate one‐dimensional nanofibers with aligned MWCNTs.magnified image
Effective reaction rates of a thin catalyst layer
Authors: Lenzinger Michael , Schweizer Ben 
Published: September 2009

AbstractThe catalyst layer in a fuel cell can be described with a system of reaction diffusion eq
uations for the oxygen concentration and the protonic overpotential. The Tafel law gives an exponential expression for the reaction rate, and the Tafel slope is a coefficient in this law. We present a rigorous thin layer analysis for two reaction regimes. In the case of thin catalyst layers and bounded potentials, the original Tafel law enters as an effective boundary condition. Instead, in the case of large protonic overpotentials, we derive an exponential law that contains the doubled Tafel slope. Copyright © 2009 John Wiley & Sons, Ltd.
Experimental protocol for activation‐induced manganese‐enhanced MRI (AIM‐MRI) based on quantitative determination of Mn content in rat brain by fast T1 mapping
Authors: Tambalo S. , Daducci A. , Fiorini S. , Boschi F. , Mariani M. , Marinone M. , Sbarbati A. , Marzola P. 
Published: September 2009

AbstractIn activation‐induced manganese‐enhanced MRI (AIM‐MRI) experiments, differential accumulation of Mn in activated and silent brain areas is generally assessed using T1‐weighted images and quantified by the enhancement of signal intensity (SI), calculated with reference to SI before Mn administration or to SI of brain regions unaffected by the specific stimulus. However, SI enhancement can be unreliable when animals are removed from and reinserted into the magnet. We have developed an experimental protocol based on repeated intraperitoneal (i.p.) injections of Mn, quantitative determination of T1, and coregistration of images to a rat brain atlas that allows absolute quantification of Mn concentration in selected brain areas. Results showed that interanimal variability of postcontrast T1 values was very low (compared to the experimental error in T1 determinations) allowing detection of differential regional Mn uptake in stimulated and unstimulated animals. In addition we have determined in vivo relaxivity of Mn in brain tissue and its frequency dependence. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
An elasto‐plastic three phase model for partially saturated soil for the finite element simulation of compressed air support in tunnelling
Authors: Nagel F. , Meschke G. 
Published: September 2009

AbstractThis paper presents a fully coupled finite element formulation for partially saturated soil as a triphasic porous material, which has been developed for the simulation of shield tunnelling with heading face support using compressed air. While for many numerical simulations in geotechnics use of a two‐phase soil model is sufficient, the simulation of compressed air support demands the use of a three‐phase model with the consideration of air as a separate phase. A multiphase model for soft soils is developed, in which the individual constituents of the soil—the soil skeleton, the fluid and the gaseous phase—and their interactions are considered. The triphasic model is formulated within the framework of the theory of porous media, based upon balance equations and constitutive relations for the soil constituents and their mixture. An elasto‐plastic, cam–clay type model is extended to partially saturated soil conditions by incorporating capillary pressure according to the Barcelona basic model. The hydraulic properties of the soil are described via DARCY's law and the soil–water characteristic curve after VAN GENUCHTEN. Water is modelled as an incompressible and air as a compressible phase. The model is validated by means of selected benchmark problems. The applicability of the model to geotechnical problems is demonstrated by results from the simulation of a compressed air intervention in shield tunnelling. Copyright © 2009 John Wiley & Sons, Ltd.
A new Taylor collocation method for nonlinear Fredholm‐Volterra integro‐differential equations
Authors: Bülbül Berna , Gülsu Mustafa , Sezer Mehmet 
Published: September 2009

AbstractThe aim of this article is to present an efficient numerical procedure for solving nonlinear integro‐differential equations. Our method depends mainly on a Taylor expansion approach. This method transforms the integro‐differential equation and the given conditions into the matrix equation which corresponds to a system of nonlinear algebraic equations with unkown Taylor coefficients. The reliability and efficiency of the proposed scheme are demonstrated by some numerical experiments and performed on the computer program written in Maple10. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
Sequential quadratic programming and analytic hierarchy process for nonlinear multiobjective optimization of a hydropower network
Authors: Moosavian S. Ali A. , Ghaffari Ali , Salimi Amir 
Published: September 2009

AbstractIn this paper, an optimal annual scheduling for power generation (i.e. rule curves and volume of water releases) in serial or parallel hydropower plants is developed. Multiobjective programming and weighted sum method are used to convert a multiobjective problem to a single objective one. Furthermore, to obtain viable alternatives under existing uncertainty, some random weight vectors in the whole weighting space are generated and for each weight vector an optimal solution is found using sequential quadratic programming (SQP). Then, analytic hierarchy process (AHP) is used to select the best solution according to a given criterion, and determine the most preferred one. Besides, this method does not require choosing a priori preference for the objective function, thus making an ideal tool for handling complicated multiobjective models and easy to use with the aid of computer programs. Combination of multiobjective optimization and multicriteria decision analysis (MCDA) is an integrated methodology that is capable of dealing with complex water management problems. Various scenarios for dry, median, and wet years are assumed based on stochastic flows from external sources (e.g. flooding rivers, unexpected rains, etc.) coming into each reservoir, and turbine power generation is obtained from hill diagrams provided by the manufacturer. The application of this methodology is illustrated in a case study for optimal scheduling of Karoon River Basin, where the decision support system and optimization routines are implemented in MATLAB. The total energy productions for 10 optimized solutions under dry, median, and wet scenarios (generated from forty‐year historical inflow records) are calculated, and specific water consumption for each reservoir is obtained in different months. This can significantly help decision makers to have an optimal and more intelligent management over energy productions in hydropower plants and associated thermal power plants. Copyright © 2009 John Wiley & Sons, Ltd.
Polymeric gels and hydrogels for biomedical and pharmaceutical applications
Authors: Jagur‐Grodzinski Joseph 
Published: September 2009

AbstractHydrogels are formed when a three‐dimensional polymeric network is loosely crosslinked. They are swollen by water but not dissolved in it. Hydrogels may display reversible sol–gel transitions, induced by changes in the environmental conditions such as temperature, pH, ionic strength, phase separation, wave length of light, crystallinity, etc. Hydrogel is described as smart or intelligent when sharp transition is induced by small change in such conditions. For the shape‐memory hydrogels, reversible change in shape may also be induced by such stimuli. The preparation and applications of the molecularly imprinted polymeric hydrogels (MIPs) are illustrated by a few examples. The use of shape sensitive hydrogels in microfluidic is mentioned. Application of hydrogels for chronobiology and chronotherapy is outlined. The conversion of hydrogels into aerogels and their respective properties is discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Using health information technology to improve drug monitoring: a systematic review
Authors: Hayward Geoffrey L. , Parnes Aaron J. , Simon Steven R. 
Published: September 2009

AbstractPurposeTo conduct a systematic review of current evidence regarding the use of health information technology (HIT) interventions to improve drug monitoring in ambulatory care.MethodsWe searched PubMed, CINAHL, the Cochrane Library, and other computerized databases from 1 January 1998 to 30 June 2008 using the key words “drug monitoring,” “medical records systems, computerized,” “ambulatory care,” and “outpatients.” We manually reviewed reference lists of articles identified through computer searches and asked experts in the field to review our search strategy and results for completeness.ResultsSeven relevant studies were identified. Four of these studies assessed real‐time interventions that used alerts to physicians at the time of medication ordering to ensure adequate monitoring, only one of which showed an improvement in monitoring. Of three studies using HIT outside the physician encounter, two suggested some improvement in monitoring rates. Methodological limitations were apparent in all studies identified.ConclusionsFew studies have assessed the effectiveness of HIT interventions to improve drug monitoring, and among them, there is no clear consensus regarding the most consistently effective approaches to reducing drug monitoring errors. There is a clear need for well designed randomized trials to evaluate possible interventions to reduce drug monitoring errors. Such studies should incorporate health outcomes and detailed cost analyses to further characterize the feasibility of successful interventions. Copyright © 2009 John Wiley & Sons, Ltd.
Tückisches Einlochen. Physik des Golfspiels
Authors: Mathelitsch Leopold , Thaller Sigrid 
Published: September 2009

AbstractGolfer erzielen ihre hohe Abschlagsgeschwindigkeit durch einen Bewegungsablauf, der auch die starke Rückenmuskulatur einsetzt. Dellen in den Oberflächen der Bälle verringern ihren Luftwiderstand und lassen sie weiter fliegen. Rotierenden Bällen kann der Magnus‐Effekt zusätzlichen Auftrieb geben, der den Flug verlängert. Kritisch ist der letzte Schlag beim Einlochen: Selbst im Loch befindliche Golfbälle können von ihrer Rotation wieder heraus geschleudert werden.
Farbenspiel transparenter Folien
Authors: Schlichting H. Joachim 
Published: September 2009

AbstractTransparente Zellophanfolie, wie man sie beispielsweise zum Einwickeln von Blumensträußen benutzt, kann den Blumen ästhetisch durchaus Konkurrenz machen. Voraussetzung ist allerdings, dass man sie im Lichte des blauen Himmels auf einer gläsernen Unterlage betrachtet.
Ein cooler Temperaturvermesser
Authors: Loos Andreas 
Published: September 2009

Abstract“Aus der Höhe” könnte man seinen Namen übersetzen. Angeblich ist das eine Bezugnahme auf das Pfarrhaus in dem kleinen mittelschwedischen Ort, aus dem seine Familie ursprünglich stammt. Latinisiert hört sich das natürlich viel schicker an. Und es steckt darin obendrein das Wort caelum (Himmel). Nomen est omen, möchte man da sagen. Denn sowohl die beiden Großväter des Gesuchten als auch sein Vater verdienen ihr Brot als (Mathematiker und) Astronomen.
Poren, Fleisch und Feuchtigkeit
Authors: Vilgis Thomas 
Published: September 2009

AbstractNoch immer verbreitet mancher Zeitgenosse, Fleisch müsse scharf angebraten werden, damit sich die Poren schließen und die Fleischsäfte nicht entweichen können. Diese Kochmär hält sich hartnäckig, und daher lohnt es sich, dieses Problem mit dem Auge des Physikers genauer zu betrachten. Schon stellt man fest: Garendes Fleisch verhält sich in bestimmten Bereichen wie ein “sich selbst ausdrückender Schwamm”.
Fernsehen mit Einstein
Authors: Müller Andreas 
Published: September 2009

AbstractIn einem populärwissenschaftlichen Artikel zu Auswirkungen der Relativitätstheorie im Alltag schreibt der Autor, dass für den korrekten Betrieb eines Röhrenfernsehers die Berücksichtigung der Speziellen Relativitätstheorie nötig ist. In der Röhre würden die Elektronen auf eine Geschwindigkeit beschleunigt, bei der die relativistische Massenzunahme sichtbare Auswirkungen auf den Ablenkwinkel im Magnetfeld bewirkt. Ist die Korrektur im Vergleich zum klassischen Fall wirklich in der Größenordnung einiger Pixel und somit sichtbar?
Proteomic analysis of increased Parkin expression and its interactants provides evidence for a role in modulation of mitochondrial function
Authors: Davison Eleanor J. , Pennington Kyla , Hung Chao‐Chun , Peng Jianhe , Rafiq Rumana , Ostareck‐Lederer Antje , Ostareck Dirk H. , Ardley Helen C. , Banks Rosamonde E. , Robinson Philip A. 
Published: September 2009

AbstractParkin is an ubiquitin‐protein ligase (E3), mutations of which cause juvenile onset – autosomal recessive Parkinson's disease, and result in reduced enzymic activity. In contrast, increased levels are protective against mitochondrial dysfunction and neurodegeneration, the mechanism of which is largely unknown. In this study, 2‐DE and MS proteomic techniques were utilised to investigate the effects of increased Parkin levels on protein expression in whole cell lysates using in an inducible Parkin expression system in HEK293 cells, and also to isolate potential interactants of Parkin using tandem affinity purification and MS. Nine proteins were significantly differentially expressed (±2‐fold change;p<0.05) using 2‐DE analysis. MS revealed the identity of these proteins to be ACAT2, HNRNPK, HSPD1, PGK1, PRDX6, VCL, VIM, TPI1, and IMPDH2. The first seven of these were reduced in expression. Western blot analysis confirmed the reduction in one of these proteins (HNRNPK), and that its levels were dependent on 26S proteasomal activity. Tandem affinity purification/MS revealed 14 potential interactants of Parkin; CKB, DBT, HSPD1, HSPA9, LRPPRC, NDUFS2, PRDX6, SLC25A5, TPI1, UCHL1, UQCRC1, VCL, YWHAZ, YWHAE. Nine of these are directly involved in mitochondrial energy metabolism and glycolysis; four were also identified in the 2‐DE study (HSP60, PRDX6, TPI1, and VCL). This study provides further evidence for a role for Parkin in regulating mitochondrial activity within cells.
Database on Demand – An online tool for the custom generation of FASTA‐formatted sequence databases
Authors: Reisinger Florian , Martens Lennart 
Published: September 2009

AbstractIn mass spectrometry‐based proteomics, most conventional search engines match spectral data to sequence databases. These search databases thus play a crucial role in the identification process. While search engines can derive peptides in silico from protein sequences, this is usually limited to standard digestion algorithms. Customized search databases that provide detailed control over the search space can vastly outperform such standard strategies, especially in gel‐free proteomics experiments. Here we present Database on Demand, an easy‐to‐use web tool that can quickly produce a wide variety of customized search databases.
Theoretical study of one‐ and two‐photon absorption properties of expanded donor–acceptor calix[4]arenes
Authors: Li Wen‐Chao , Feng Ji‐Kang , Ren Ai‐Min , Zhang Xiang‐Biao , Sun Chia‐Chung 
Published: September 2009

AbstractTwo types of donor(D)–acceptor(A) calix[4]arenes have been theoretically studied using DFT//B3LYP/6‐31G(d) method and ZINDO/CISD method. The calculations show that the substitution of CC by the conjugation bridge CC and NN plays an important part in altering one‐photon absorption (OPA) and two‐photon absorption (TPA) properties. The maximum OPA wavelengths of all studied compounds are less than 400 nm, which means high transparency. The geometry of the calixarenes strongly influences the TPA properties of the studied compounds. In addition, the nitro derivatives have a wider TPA response range than other non‐nitro derivatives. The tetrasubstituted calix[4]arenes (type B calixarenes) have a larger TPA cross‐section values than the bisubstituted calix[4]arenes (type A calixarenes). Copyright © 2009 John Wiley & Sons, Ltd.