bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecularly imprinted polymer for selective extraction of endocrine disrupters nonylphenol and its ethoxylated derivates from environmental solids
Authors: Núñez Laura , Turiel Esther , Martín‐Esteban Antonio , Tadeo José L. 
Published: July 2008

AbstractNonylphenol isomers (NP), linear nonylphenol (4‐n‐NP) and NP short chain ethoxylated derivates (NPEO1 and NPEO2) are degradation products of nonylphenol polyethoxylates, a worldwide used group of surfactants. All of them are considered endocrine disrupters due to their ability to mimic natural estrogens. In this paper, the preparation and evaluation of several 4‐n‐NP molecularly imprinted polymers (MIPs) for the selective extraction and clean‐up of 4‐n‐NP, NP, NPEO1 and NPEO2 from complex environmental solid samples is described. Among the different combinations tested, a methacrylic acid‐based imprinted polymer prepared in toluene provided the better performance for molecularly imprinted SPE (MISPE). Under optimum MISPE conditions, the polymer was able to selectively retain not only linear NP but also the endocrine disruptors NPEO1, NPEO2 and NP with recoveries ranging from 60 to 100%, depending upon the analyte. The developed MISPE procedure was successfully used for the determination of 4‐n‐NP, NP, NPEO1 and NPEO2 in sediments and sludge samples at concentration levels according to data reported in the literature for incurred samples. Finally, various sludge samples collected at five different sewage treatment plants from Madrid and commercial sludge for agriculture purposes were analysed. The measured concentrations of the different compounds varied from 3.7 to 107.5 mg/kg depending upon the analyte and the sample.
Determination of dimethylarginine levels in rats using HILIC‐MS/MS: An in vivo microdialysis study
Authors: Zotti Margherita , Schiavone Stefania , Tricarico Filomena , Colaianna Marilena , D'Apolito Oceania , Paglia Giuseppe , Corso Gaetano , Trabace Luigia 
Published: July 2008

AbstractNitric oxide (NO) is one of the most important mediators and neurotransmitters and its levels change under pathological conditions. NO production may be regulated by endogenous nitric oxide synthase (NOS) inhibitors, in particular asymmetric dimethylarginine (ADMA). Most of the interest is focused on ADMA, since this compound is present in plasma and urine and accumulation of ADMA has been described in many disease states but little is known about cerebrospinal fluid (CSF) concentrations of this compound and of its structural isomer symmetric dimethylarginine (SDMA). To determine the levels of methylarginines, we here present a new hydrophilic interaction chromatography (HILIC)‐MS/MS method for the precise determination of these substances in CSF from microdialysis samples of rat prefrontal cortex (PFC). The method requires only minimal sample preparation and features isotope‐labelled internal standards.
Nanotube and Three‐Way Nanotube Formation with Nonionic Amphiphilic Block Peptides
Authors: Kanzaki Tatsuya , Horikawa Yoshiki , Makino Akira , Sugiyama Junji , Kimura Shunsaku 
Published: July 2008

AbstractAmphiphilic block polypeptides having a helical hydrophobic block with a uniform chain length and a hydrophilic nonionic block were newly synthesized and self‐assembled into homogeneous nanotubes with ca. 60 nm diameter and ca. 200 nm length. The tubular assembly was shown to be elongated by heating over micrometer length without changing the diameter. Notably, a distinctive three‐way nanotube was obtained just by mixing two kinds of amphiphilic polypeptides with the same helical hydrophobic block but different chain lengths of the hydrophilic block. The morphology of the molecular assemblies was shown to be tunable from a curved sheet‐shaped assembly to a long or short nanotubular assembly and a three‐way nanotubular assembly by suitable molecular design of the hydrophobic block, selection of the chain length of the hydrophilic block, mixing two‐type block peptides, and processing such as heating.magnified image
New in situ Blends of Polyaniline and Cardanol Bio‐Resins
Authors: Souza Fernando G. , Richa Priscila , de Siervo Abner , Oliveira Geiza E. , Rodrigues Cezar H. M. , Nele Márcio , Pinto José Carlos 
Published: July 2008

AbstractCardanol, a well known natural resource, was used to produce a polymer resin in the presence of formaldehyde, catalyzed by H2SO4. Before reticulation, PAni · H2SO4 was blended with the resin. The blended material was cast into poly(propylene) cups and kept inside a desiccator under vacuum until complete water evaporation. The final in situ polymer blend was solid and could not be dissolved in ordinary solvents, indicating that a reticulated material had been obtained. Samples prepared similarly were then characterized, showing that the produced blends can be used as pressure sensing materials.magnified image
UV Curing of Organic‐Inorganic Hybrid Coatings Containing Polyhedral Oligomeric Silsesquioxane Blocks
Authors: Amerio Ezio , Sangermano Marco , Colucci Giovanna , Malucelli Giulio , Messori Massimo , Taurino Rosa , Fabbri Paola 
Published: July 2008

AbstractHybrid nanocomposite coatings were prepared by the UV‐curing technique with a methacrylic oligomer and multifunctional methacrylic polyhedral oligomeric silsesquioxane blocks (POSS®). The results obtained from the polyhedral compounds were compared with those of a disordered framework obtained by the condensation of a silica precursor (MEMO). The inorganic domains generated during synthesis created constraints in movement of polymer segments, which reflected in an increase in Tg of the hybrid nanocomposite coatings. The films were transparent. The random structure obtained by the condensation of the MEMO showed a stronger effect on Tg than that observed by introducing POSS®. The effect of inorganic domains reflected on thermal stability, surface hardness and mechanical properties of the hybrid nano‐composite coatings.magnified image
Effect of the Fiber Size on the Physicochemical and Mechanical Properties of Composites of Epoxy and Date Palm Tree Fibers
Authors: Sbiai Adil , Kaddami Hamid , Fleury Etienne , Maazouz Abderrahim , Erchiqui Fouad , Koubaa Ahmed , Soucy Joel , Dufresne Alain 
Published: July 2008

AbstractLignocellulosic fibers from date palm trees were employed to reinforce an epoxy matrix. Two fiber sizes were used, with the length and diameter in the range of 20–30 and 1.5–3 mm, respectively, for the so‐called long fibers, and in the range of 5–15 and 0.25–0.75 mm, respectively, for the so‐called short fibers. The morphologies of the resulting composites, as well as their thermal, mechanical, and water sorption properties were evaluated. Strong interactions between both components and etherification reactions may occur between the hydroxyl groups of the fibers and the epoxy groups of the epoxy‐amine reactive mixture. These effects are emphasized when decreasing the size of the fibers.magnified image
Urethral injection therapy: What is the mechanism of action?
Authors: Klarskov Niels , Lose Gunnar 
Published: July 2008

AbstractAimsThe mechanism of action of injection therapy is virtually unknown. Urethral Pressure Reflectometry (UPR) is a novel technique for measuring pressure and cross‐sectional area in the urethra. UPR which provides reliable physiological meaningful parameters was used to study the mechanism of urethral injection therapy.Materials and MethodsFifteen patients with stress urinary incontinence (nine women) and mixed incontinence (six women) were investigated with UPR before and 101 days after urethral injection therapy. The patients subjectively judged if their stress and urge symptoms were cured/improved almost unchanged or worsened.ResultsTen women were cured/improved after the injection therapy. None became worse. Six patients had urge symptoms before injection therapy which did not change after the procedure. The patients were divided into two groups based on their subjective assessments of effect. One group with effect (10 women) and 1 group without effect (5 women). The patients had significantly higher squeezing opening pressure after the treatment. The other parameters were unchanged. The mean squeezing opening pressure increased significantly (P < 0.01) more in the group of patients with effect (10.6 cmH2O) than in the group without effect (−1.6 cmH2O).ConclusionInjection therapy may work by increasing the power of the urethral sphincter. The bulking material may function as additional central filler volume which increase the length of the muscle fiber and thereby the power of the sphincter. Neurourol. Urodynam. 27:789–792, 2008, © 2008 Wiley‐Liss, Inc.
Proteomic analysis of antioxidant strategies of Staphylococcus aureus: Diverse responses to different oxidants
Authors: Wolf Carmen , Hochgräfe Falko , Kusch Harald , Albrecht Dirk , Hecker Michael , Engelmann Susanne 
Published: July 2008

AbstractThe high resolution 2‐D protein gel electrophoresis technique combined with MALDI‐TOF MS and a recently developed fluorescence‐based thiol modification assay were used to investigate the cellular response of Staphylococcus aureus to oxidative stress. Addition of hydrogen peroxide, diamide, and the superoxide generating agent paraquat to exponentially growing cells revealed complex changes in the protein expression pattern. In particular, proteins involved in detoxification, repair systems, and intermediary metabolism were found to be up‐regulated. Interestingly, there is only a small overlap of proteins induced by all these stressors. Exposure to hydrogen peroxide mediated a significant increase of DNA repair enzymes, whereas treatment with diamide affected proteins involved in protein repair and degradation. The activity of proteins under oxidative stress conditions can be modulated by oxidation of thiol groups. In growing cells, protein thiols were found to be mainly present in the reduced state. Diamide mediated a strong increase of reversibly oxidized thiols in a variety of metabolic enzymes. By contrast, hydrogen peroxide resulted in the reversible oxidation especially of proteins with active site cysteines. Moreover, high levels of hydrogen peroxide influenced the pI of three proteins containing cysteines within their active sites (GapA1, AhpC, and HchA) indicating the generation of sulfinic or sulfonic acid by irreversible oxidation of thiols.
Proteomic profile of osteoclast membrane proteins: Identification of Na+/H+ exchanger domain containing 2 and its role in osteoclast fusion
Authors: Ha Byung Geun , Hong Jung Min , Park Ju‐Yong , Ha Mi‐Hyun , Kim Tae‐Ho , Cho Je‐Yeol , Ryoo Hyun‐Mo , Choi Je‐Yong , Shin Hong‐In , Chun So Young , Kim Shin‐Yoon , Park Eui Kyun 
Published: July 2008

AbstractOsteoclast formation and bone resorption are multiple processes that involve the participation of specialized membrane structures and their associated proteins. In this study, we used an MS to analyze the profile of proteins associated with osteoclast membranes and focused on the function of channel proteins in osteoclast differentiation and function. We filtered out with a SEQUEST score greater than 10 and a peptide hit number of more than 2, resulting in the identification of 499 proteins that were commonly found in both macrophages and osteoclasts, 96 proteins selectively found in osteoclasts, and 179 proteins selectively found in macrophages. The proteins that were selectively found in osteoclasts were classified based on their localizations: plasma membrane (17%), ER/Golgi and lysosome/endosome (15%), mitochondrion (18%), nucleus (13%), cytosol (19%), and unknown (18%). Proteins associated with osteoclast function such as v‐ATPase, IGF2R, TRAP, and cathepsin K were found in osteoclasts as previously shown. We found several ion channel proteins such as Ank and Nhedc2 and signaling molecules such as Dock5 and RAB‐10 in osteoclasts. Inhibition of the Na+/H+ exchanger family by amiloride suppressed RANKL‐induced osteoclast fusion and bone resorption. In addition, shRNA for Nhedc2 inhibited osteoclast differentiation. Our results provide a proteomic profile of osteoclast membrane proteins and identify Nhedc2, which is probably associated with proton transport in osteoclasts, as a regulator of osteoclast function.
The post‐translational modification profile of the forkhead transcription factor FOXL2 suggests the existence of parallel processive/concerted modification pathways
Authors: Benayoun Bérénice A. , Auer Jana , Caburet Sandrine , Veitia Reiner A. 
Published: July 2008

AbstractThe transcription factor Forkhead box L subfamily member 2 (FOXL2) is involved in craniofacial development and ovarian function. Using 2‐DE and immunoblotting, we show that it is highly modified post‐translationally. The most outstanding feature of its migration profile is the presence of two distinct modification “trains” and the absence of intermediates. A theoretical analysis of the modification profile of FOXL2 suggests that it undergoes parallel processive/concerted modifications. The absence of intermediates is compatible with the recruitment of poorly modified FOXL2 into a post‐translational “modification factory.”
Influence of post‐radiation deformation on TSL and absorption spectra of irradiated MgO crystals
Authors: Kvatchadze V. , Dekanozishvili G. , Galustashvili M. , Kalabegishvili T. , Abramishvili M. , Akhvlediani Z. 
Published: July 2008

AbstractThermally stimulated luminescence (TSL) and optical and paramagnetic absorption spectra of MgO and MgO:V2+ have been investigated after quasi‐elastic and plastic deformations. Splitting of the low‐temperature peak (∼450 K) in TSL curves caused by the deformation in both nominally pure and impure crystals is explained by the formation of an excess of vacancies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the electronic structures of CaMoO4 crystal related to oxygen vacancy
Authors: Pu Chunying , Liu Tingyu , Zhang Qiren 
Published: July 2008

AbstractThe electronic structure of CaMoO4 crystal containing oxygen vacancy with the optimized lattice structure is studied within the framework of the fully relativistic self‐consistent Dirac–Slater theory, using a numerically discrete variational (DV‐Xα) method. The calculated results indicate that the oxygen vacancy causes the appearance of the 4d state of molybdenum in the forbidden band. The optical transition energy from the 2p state of oxygen to the 4d state of molybdenum is 2.23 eV, corresponding to the 557 nm absorption band, which is very close to the experimental results. The F and F+ centers have donor energy levels and they occur in the forbidden band below the conduction band at 0.8 eV and 1.3 eV, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of vanadium doping on the electrical and structural properties of GdBa2Cu3–xVx O7–δ
Authors: Javanmard H. , Bazargan S. , Akhavan M. 
Published: July 2008

AbstractThe compounds with composition GdBa2Cu3–x Vx O7–δ and x = 0.0, 0.05, 0.1, 0.15, 0.2 and 0.3 have been prepared by the solid‐state reaction method. The XRD spectra indicate single‐phase formation of the compounds. The transition temperature decreases considerably with vanadium concentration to Tc = 26.4K for x = 0.3. The host sample is in the orthorhombic phase, but by increasing the V content the structure approaches the tetragonal phase, and for x = 0.3 the structure is nearly tetragonal. The normal state resistivity has been compared with 2D‐VRH, 3D‐VRH, and CG regimes, which shows that the 2D‐VRH and CG are in better agreement for our samples. The localization length is calculated for the 2D‐VRH, which shows a decrease with doping, and for x = 0.15 this drop is significant. Based on our preparation conditions, V is likely to remain as V4+ in the compound, and because of the high tendency of V4+ for achieving the octahedral structure, it appears that vanadium enters the chains, and accounts for the observed changes in the crystal structure and the superconducting properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elastic and electronic properties of hexagonal and cubic polymorphs of tungsten monocarbide WC and mononitride WN from first‐principles calculations
Authors: Suetin D. V. , Shein I. R. , Ivanovskii A. L. 
Published: July 2008

AbstractWe have performed accurate ab‐initio total energy calculations using the full‐potential linearized augmented plane wave (FP‐LAPW) method with the generalized gradient approximation (GGA) for the exchange‐correlation potential to investigate the elastic, electronic and cohesive properties of hexagonal and cubic polymorphs of WC and WN. The optimized lattice parameters, independent elastic constants (Cij), bulk moduli (B), shear moduli (G), as well as band structure, density of states, electron density distribution and cohesive energies are obtained and analyzed in comparison with the available theoretical and experimental data. In addition, for the first time, the numerical estimates are made for some elastic parameters of the polycrystalline WC and WN ceramics (in the framework of the Voigt–Reuss–Hill approximation), namely bulk and shear moduli, compressibility (β), Young's moduli (Y), Poisson's ratio (ν) and Lamé's coefficients (μ, λ). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence of Pb2+ ions in YAG:Pb single‐crystalline films
Authors: Zorenko Yu. , Gorbenko V. , Voznyak T. , Zorenko T. 
Published: July 2008

AbstractLuminescence of Pb2+ ions in YAG:Pb single‐crystalline films (SCF) with different lead content in the range of 0.01–0.3 at% was investigated by means of cathodoluminescence, time‐resolved emission/excitation spectra and luminescence decay kinetic under excitation by synchrotron radiation. The nature of Pb2+ ion‐related emission bands in the UV and visible ranges and their prevailing excitation mechanism are considered. Strong mixing of the 1P1 excited states of Pb2+ ions and the conduction‐band states of the YAG host was found. A scheme of energy levels of Pb2+ center in YAG and LuAG is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐situ dispersion of ZrO2 nano‐particles coated with pentacene
Authors: Sagmeister M. , Brossmann U. , List E. J. W. , Ochs R. , Szabó D. V. , Würschum R. 
Published: July 2008

AbstractStable suspensions of pentacene functionalised ZrO2 nano‐particles were synthesised using a microwave plasma process. The particles were dispersed in‐situ in ethylene glycol. The formation of coated particles with small cores and a well defined size in the range of 3–5 nm was shown by X‐ray diffraction. In difference to resublimed pure pentacene, suspensions of the coated nano‐particles remained stable for weeks, as confirmed by the observation of a small aggregate size in dynamic light scattering. Thin films of the particles on Si based substrates were obtained by drop‐casting. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Unique dielectric properties in polyaniline/poly(vinylidene fluoride) composites induced by temperature variation
Authors: Yuan Jin‐Kai , Dang Zhi‐Min , Bai Jinbo 
Published: July 2008

AbstractTo explore an effect of temperature on the dielectric properties in polyaniline/poly(vinylidene fluoride) (PANI/PVDF) composites, the dielectric properties of these composites with different volumetric fractions of PANI (ƒPANI) were studied in a wide temperature range. An increase in the effective conductivity (σeff) and dielectric permittivity (ϵeff) was observed with increasing temperature in all PANI/PVDF composites. Particularly, for the composite with ƒPANI = 0.01, less than the percolation threshold (ƒC = 0.045), the increase in σeff and ϵeff was most significant. A tunneling effect could be responsible for the unique dielectric properties. The results provided us useful information related to the microstructure of composites, which was not reported previously. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of the current linearity at low illumination of high‐efficiency back‐junction back‐contact silicon solar cells
Authors: Granek Filip , Hermle Martin , Glunz Stefan W. 
Published: July 2008

AbstractThe relation between current and illumination intensity of three structures of high‐efficiency back‐junction back‐contact silicon solar cells was analyzed. Both, n‐type cells with non‐diffused front surface and p‐type cell with floating n‐emitter show a pronounced non‐linearity due to strong illumination dependence of the passivation quality of the non‐diffused surface and the floating junction respectively. Quantum efficiency (QE) of this cell type drops significantly for the illumination lower than 0.5 suns. In contrast the QE of n‐type cells with n+‐front surface field (FSF) is linear. Low illumination current characteristics of all three of the analyzed structures could be well described by physical models. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Higher Abel-Jacobi maps for 0-cycles
Authors: Kerr Matt 
Published: July 2008

AbstractStarting from the candidate Bloch-Beilinson filtration onconstructed in [L2], we develop and describe geometrically a series of Hodgetheoretic invariants Ψidefined on the graded pieces. Explicit formulas (in terms of currents and membrane integrals) are given for certain quotients of the Ψi, with applications to 0-cycles on products of curves.
Integration of a plug-and-play desktop robotic system
Authors: Su Jianbo , Zhang Yanjun 
Published: July 2008

SUMMARYThis paper describes the development of a desktop robotic system that enables the plug-and-play function through the USB (universal serial bus) port of a personal computer (PC). Thus a new kind of desktop PC peripheral is invented that has programmable manipulability. The robotic system is realized on an internally distributed control structure that facilitates higher system reliability. A PID control algorithm is implemented on a prototype of the proposed system, to demonstrate the system's ability to implement feedback control. Experimental results show the performance and properties of the proposed system.
The maintained discharge of rat retinal ganglion cells
Authors: FREEMAN DANIEL K. , HEINE WALTER F. , PASSAGLIA CHRISTOPHER L. 
Published: July 2008

AbstractAction potentials were recorded from rat retinal ganglion cell fibers in the presence of a uniform field, and the maintained discharge pattern was characterized. Spike trains recorded under ketamine–xylazine anesthesia were generally stationary, while those recorded under urethane anesthesia often showed slow, undriven, quasiperiodic fluctuations in firing rate. In light of these nonstationarities, interspike interval distributions and power spectral densities are reported for data collected primarily under ketamine–xylazine. The majority of cells had multimodal interval distributions, with the first peak in the range of 25.0–38.5 ms and the subsequent peaks occurring at integer multiples of the first peak. Cells with unimodal distributions were fit well by a gamma distribution function. Interval and spike count statistics showed that ON cells tended to fire faster than OFF cells and that cells with higher rates fired in a more regular manner, with the coefficient of variation covering a wide range of values across all cells (0.43–0.97). Both ON and OFF cells show serial correlations between adjacent interspike intervals, while ON cells also showed second-order correlations. Cells with multimodal interval distribution showed a strong peak at high frequencies in the power spectra in the range of 28.9–41.4 Hz. Oscillations were present under both anesthetic conditions and persisted in the dark at a slightly lower frequency, implying that the oscillations are generated independent of any light stimulus but can be modulated by light level. The oscillation frequency varied slightly between cells of the same type and in the same eye, suggesting that multiple oscillatory generating mechanisms exist within the retina. Cells with high-frequency oscillations were described well by an integrate-and-fire model with the input consisting of Gaussian noise plus a sinusoid where the phase was jittered randomly to account for the bandwidth present in the oscillations.