bluuebunny/crossref_metadata_2025 huggingface dataset:
Zygomaticomaxillary buttress reconstruction of midface defects with the osteocutaneous radial forearm free flap
Authors: Andrades Patricio , Rosenthal Eben L. , Carroll William R. , Baranano Christopher F. , Peters Glenn E.
Published: July 2008

Background.

The purpose of this study was to evaluate morbidity, functional, and aesthetic outcomes in midface zygomaticomaxillary buttress reconstruction using the osteocutaneous radial forearm free flap (OCRFFF).

Methods.

A retrospective review of 24 consecutive patients that underwent midface reconstruction using the OCRFFF was performed. All patients had variable extension of maxillectomy defects that requires restoration of the zygmatico‐maxillary buttress. After harvest, the OCRFFF was fixed transversely with miniplates connecting the remaining zygoma to the anterior maxilla. The orbital support was given by titanium mesh when needed that was fixed to the radial forearm bone anteriorly and placed on the remaining orbital floor posteriorly. The skin paddle was used for intraoral lining, external skin coverage, or both. The main outcome measures were flap success, donor‐site morbidity, orbital, and oral complications. Facial contour, speech understandability, swallowing, oronasal separation, and socialization were also analyzed.

Results.

There were 6 women and 18 men, with an average age of 66 years old (range, 34–87). The resulting defects after maxillectomy were (according to the Cordeiro classification; Disa et al, Ann Plast Surg 2001;47:612–619; Santamaria and Cordeiro, J Surg Oncol 2006;94:522–531): type I (8.3%), type II (33.3%), type III (45.8%), and type IV (12.5%). There were no flap losses. Donor‐site complications included partial loss of the split thickness skin graft (25%) and 1 radial bone fracture. The most significant recipient‐site complications were severe ectropion (24%), dystopia (8%), and oronasal fistula (12%). All the complications occurred in patients with defects that required orbital floor reconstruction and/or cheek skin coverage. The average follow‐up was 11.5 months, and over 80% of the patients had adequate swallowing, speech, and reincorporation to normal daily activities.

Conclusions.

The OCRFFF is an excellent alternative for midface reconstruction of the zygomaticomaxillary buttress. Complications were more common in patients who underwent resection of the orbital rim and floor (type III and IV defects) or external cheek skin. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Précis of ‘An Abductive Theory of Scientific Method’
Authors: Haig Brian D.
Published: July 2008

This short article is a précis of the author's (2005a) abductive theory of scientific method. This theory of method assembles a complex of specific strategies and methods of relevance to psychology that are employed in the detection of empirical phenomena and the subsequent construction of explanatory theories. A characterization of the nature of phenomena is given, and the process of their detection is briefly described in terms of a multistage model of data analysis. The construction of explanatory theories is shown to involve their generation through abductive, or explanatory, reasoning, their development through analogical modeling, and their fuller appraisal in terms of judgments of the best of competing explanations. The nature and limits of this theory of method are discussed in the light of relevant developments in scientific methodology. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64:1–4, 2008.
Insight into microwave irradiation and enzyme catalysis in enantioselective resolution of RS‐( ± )‐methyl mandelate
Authors: Yadav Ganapati D , Sajgure Ashwini D , Dhoot Shrikant B
Published: July 2008

BACKGROUND:

Mandelic acid enantiomers are important chiral analogs used for the resolution of racemic alcohols and amines. R‐(−)‐mandelic acid is a precursor for the production of semi‐synthetic penicillins and cephalosporins and also for the synthesis of various pharmaceuticals. Production of optically pure mandelic acid enantiomers is commercially significant. This work deals with the resolution of RS‐( ± )‐methyl mandelate to produce optically pure R‐(−)‐mandelic acid in non‐aqueous media via lipase‐catalyzed hydrolysis under microwave irradiation.

RESULTS:

Among three commercial lipases, Novozym 435 (Candida antartica B immobilized on macroporous polyacrylate resin) was found to be the most effective in the selective hydrolysis of R‐(−)‐methyl mandelate to R‐(−)‐mandelic acid from the racemic mixture of RS‐( ± )‐methyl mandelate, with an optical purity (eep) of 84.2% after 4 h at 50 °C. The effects of various parameters were studied to arrive at the optimum parameters and kinetics. The optimum catalyst loading was found to be 5 mg cm−3 at a concentration of 0.25 mmol cm−3 each of methyl mandelate and water. Based on the initial rate studies and concentration profiles, a complete rate equation is proposed, which includes the irreversible inactivation caused by RS‐( ± )‐methyl mandelate, and it follows the ternary complex mechanism with dead end inhibition by RS‐( ± )‐methyl mandelate.

CONCLUSION:

Novozym 435 is the most active lipase for resolution of R‐(−)‐mandelic acid from RS‐ ( ± )‐methyl mandelate in tert‐butanol. Various equilibrium constants were evaluated and simulations were performed giving excellent agreement between the two. Copyright © 2008 Society of Chemical Industry
Two‐dimensional liquid chromatography coupled with mass spectrometry for the analysis of Lobelia chinensis Lour. using an ESI/APCI multimode ion source
Authors: Zhou Ying , Wang Yan , Wang Renfeng , Guo Fei , Yan Chao
Published: July 2008

A comprehensive approach for the separation and identification of components in a traditional Chinese medicine Lobelia chinensis Lour. was developed using 2D‐HPLC coupled with an online photodiode array (PDA) detector and a mass spectrometer. The extract of L. chinensis Lour. was separated on a CN column in the first‐dimensional HPLC, and then each of the collected fractions was further separated on an ODS column followed by an online PDA detector. After separation in the two different chromatographic modes, the eluents were delivered to a quadrupole mass spectrometer equipped with a multimode ion source of an ESI and an atmospheric pressure chemical ionization (ESI/APCI). At least 536 components in L. chinensis Lour. extract were detected and 6 of them were identified as apigenin 7‐O‐rutinoside, luteolin, lobetyolinin, lobetyolin, diosmin, and linarin, respectively, according to their UV spectrum and mass spectrum. The results demonstrated the powerful resolution, high peak capacity, as well as the identification capability of the 2D‐HPLC combined with PDA and ESI/APCI‐MS for the analyses of complex samples.
Capillary electrophoretic determination of main components of natural dyes with MS detection
Authors: Surowiec Izabella , Pawelec Katarzyna , Rezeli Melinda , Kilar Ferenc , Trojanowicz Marek
Published: July 2008

CE with UV‐Vis and MS detections was investigated as a technique for detection of main components of selected natural dyes of plant and insect origin. The BGE giving the best separation of the investigated flavonoids and anthraquinoids, suitable for MS detection consisted of 40 mM ammonium acetate solution of pH 9.5 with 40% ACN. LODs obtained with MS detection were even one order of magnitude lower than the ones obtained with UV‐Vis detection. Application of MS detection enabled determination of eleven dye compounds from three different chemical groups in 15 min. and proved to be more satisfactory than diode‐array detection in the electrophoretic analysis of main classes of natural dyes both in terms of selectivity and sensitivity of analysis.
Microwave‐assisted silylation followed by gas chromatography/mass spectrometry for rapid determination of ergosterol in cigarettes
Authors: Sha Yunfei , Deng Chunhui , Zhang Haobo , Xie Wenyan , Liu Baizhan
Published: July 2008

Ergosterol is one of the important precursors of tumorigenic polynuclear aromatic hydrocarbons. To the best of our knowledge, a large amount of ergosterol is present in moldy cigarettes, which derives from fungal contaminations. Thus, the development of a simple, fast, and efficient method for the analysis of ergosterol is in great demand. In this paper, GC/MS following microwave‐assisted silylation (MAS) was developed for the rapid quantitative analysis of ergosterol in cigarettes for the first time. In our work, total ergosterol in cigarettes after NaOH saponification was extracted with hexane, and then was fast derivatized with bis(trimethylsilyl)trifluoroacetamide (BSTFA) under microwave irradiation. Finally, the ergosterol trimethylsilyl derivative was analyzed by GC/MS. Derivatization conditions including microwave reaction solvent, irradiation time, and power were investigated. Method validations (linear range, LOD, precision, and recovery) were also studied. The results showed that the proposed method provided a fast, simple, and sensitive approach for the determination of ergosterol in cigarettes. Finally it was successfully applied to the analysis of ergosterol in normal and mildewy cigarettes.
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

Nonylphenol 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

Nitric 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

Amphiphilic 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.

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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

Cardanol, 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.

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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

Hybrid 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.

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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

Lignocellulosic 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.

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Urethral injection therapy: What is the mechanism of action?
Authors: Klarskov Niels , Lose Gunnar
Published: July 2008

Aims

The 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 Methods

Fifteen 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.

Results

Ten 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).

Conclusion

Injection 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

The 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

Osteoclast 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

The 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

Thermally 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

The 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

The 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

We 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

Luminescence 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

Stable 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

To 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

The 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

Starting 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

This 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

Action 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.
Media Violence and Youth Violence
Authors: Hopf Werner H. , Huber Günter L. , Weiß Rudolf H.
Published: July 2008

The frequency of exposure to media violence and eight additional risk factors were path-analyzed in a 2-year longitudinal study. The exposure to media violence (total score) affected students’ later violence (β = .28) and later violent delinquency (β = .30) more strongly than other risk factors. Direct effects were also caused by risk factors assessed at Time 1, which in turn were reinforced by the remaining risk factors on the second or third stratum of analysis. Of particular importance are the findings that (1) playing violent electronic games is the strongest risk factor of violent criminality and (2) both media-stimulated and real experiences of aggressive emotions associated with the motive of revenge are core risk factors of violence in school and violent criminality. The results of our study show that the more frequently children view horror and violence films during childhood and the more frequently they play violent electronic games at the beginning of adolescence the higher will these students’ violence and delinquency be at the age of 14.
Multi‐point observations of the inner boundary of the plasma sheet during geomagnetic disturbances
Authors: Runov A. , Angelopoulos V. , Ganushkina N. , Nakamura R. , McFadden J. , Larson D. , Dandouras I. , Glassmeier K.‐H. , Carr C.
Published: July 2008

We report on the THEMIS and Double Star TC‐1 observations at the geocentric distances of 3 < R < 8 RE during substorms on March 23, 2007. THEMIS crossed the inner boundary of the equatorial dusk‐side plasma in the string‐of‐pearls configuration, allowing the dynamics of particle populations to be traced within time ranges from hours to 10 minutes. Observations show co‐existence of the plasma sheet ion population (5 – 30 keV) with the ring current ion population (100 – 1000 keV) at 4 < R < 6 RE. The plasma sheet population was characterized by pronounced “nose”‐like dispersion with the spectral density maximum at ∼10 keV. The plasma sheet boundary, defined by a sharp decrease of the ∼1 keV electron flux, moved inward to R = 4 and outward back to ∼8 RE within about 1 hour. Local enhancements of the plasma sheet (1 – 5 keV) electron flux with the characteristic time scale of 2 – 10 min were detected at 5 < R < 6 RE during the substorm.
Deep low‐frequency tremors as a proxy for slip monitoring at plate interface
Authors: Hiramatsu Yoshihiro , Watanabe Tomoko , Obara Kazushige
Published: July 2008

We propose a new method to monitor slip at the plate interface using non‐volcanic deep‐low frequency (DLF) tremors. We assume that a DLF tremor is the superposition of frequently excited intermittent events, meaning that the envelope of the reduced displacement of the DLF tremor provides an apparent moment rate function. We estimate a conversion factor from the apparent moment to the seismic moment with an assumption that a total size of DLF tremors of an episode is proportional to the size of corresponding slow slip event (SSE). The cumulative seismic moment estimated by DLF tremors is consistent with that estimated from geodetic methods and provides appropriate slip and slip rate at the plate interface. This proves our assumptions and demonstrates that DLF tremors are useful tool for real‐time monitoring of the slip at the plate interface.
Estradiol Attenuates Neuroprotective Benefits of Isoflurane Preconditioning in Ischemic Mouse Brain
Authors: Wang Lan , Kitano Hideto , Hurn Patricia D , Murphy Stephanie J
Published: July 2008

Isoflurane preconditioning (IsoPC) neuroprotection in experimental stroke is male-specific. We determined whether estradiol alters ischemic outcomes in IsoPC brain and examined the role of estrogen receptors (ERs). Seven to 10 days before preconditioning, ovariectomized (OVX) mice were implanted with estradiol, vehicle, or ER subtype agonists. OVX ± estradiol, OVX ± vehicle, OVX ± ER agonists, and ER subtype wild-type (WT) and knockout (KO) mice were preconditioned for 4 h with sham anesthetic preconditioning (sham PC) or 1% IsoPC and recovered for 24 h. Mice then underwent 2 h of middle cerebral artery occlusion followed by 22 h of reperfusion. Infarct volumes were determined by 2,3,5-triphenyltetrazolium chloride staining, with comparisons between IsoPC and corresponding sham PC for each treatment group. Decreased infarct injury was seen in IsoPC OVX ± vehicle, whereas estradiol in IsoPC OVX mice enhanced ischemic damage. In ER studies, increased infarct volumes were seen in IsoPC ERWT mice regardless of ER subtype. IsoPC in ERαKO mice had no effect on infarction volume but reduced only cortical ischemic damage in ERβKO mice. In OVX + ERβ agonist, IsoPC had no effect on infarction volume. In OVX + ER/α agonist, IsoPC increased cortical infarct volume. Estradiol depresses the brain's protective response to IsoPC and may exacerbate cortical ischemic injury mainly through an ERβ-dependent mechanism.
PKC isoenzymes differentially modulate the effect of thrombin on MAPK-dependent RPE proliferation
Authors: Palma-Nicolas Jose P. , López Edith , López-Colomé Ana María
Published: July 2008

Thrombin signalling through PAR (protease-activated receptor)-1 is involved in cellular processes, such as proliferation, differentiation and cell survival. Following traumatic injury to the eye, thrombin signalling may participate in disorders, such as PVR (proliferative vitreoretinopathy), a human eye disease characterized by the uncontrolled proliferation, transdifferentiation and migration of otherwise quiescent RPE (retinal pigment epithelium) cells. PARs activate the Ras/Raf/MEK/ERK MAPK pathway (where ERK is extracellular-signal-regulated kinase, MAPK is mitogen-activated protein kinase and MEK is MAPK/ERK kinase) through the activation of Gα and Gβγ heterotrimeric G-proteins, and the downstream stimulation of the PLC (phospholipase C)-β/PKC (protein kinase C) and PI3K (phosphoinositide 3-kinase) signalling axis. In the present study, we examined the molecular signalling involved in thrombin-induced RPE cell proliferation, using rat RPE cells in culture as a model system for PVR pathogenesis.

 Our results showed that thrombin activation of PAR-1 induces RPE cell proliferation through Ras-independent activation of the Raf/MEK/ERK1/2 MAPK signalling cascade. Pharmacological analysis revealed that the activation of ‘conventional’ PKC isoforms is essential for proliferation, although thrombin-induced phosphorylation of ERK1/2 requires the activation of atypical PKCζ by PI3K. Consistently, thrombin-induced ERK1/2 activation and RPE cell proliferation were prevented completely by PI3K or PKCζ inhibition. These results suggest that thrombin induces RPE cell proliferation by joint activation of PLC-dependent and atypical PKC isoforms and the Ras-independent downstream stimulation of the Raf/MEK/ERK1/2 MAPK cascade. The present study is the first report demonstrating directly thrombin-induced ERK phosphorylation in the RPE, and the involvement of atypical PKCζ in this process.
Annealing effect on the luminescence properties of BaZrO3:Yb3+ microcrystals
Authors: Oliva J. , De la Rosa E. , Diaz-Torres L. A. , Salas P. , Ángeles-Chavez C.
Published: July 2008

Yb-doped barium zirconate (BaZrO3:Yb3+) was synthesized by a hydrothermal method at 100 °C. It presents a cubic perovskite crystalline phase, which is stable between 100 and 100 °C. Upon increasing the annealing temperature, two major changes are observed. (1) The near infrared (NIR) absorption band of Yb3+ decreases, and an enhancement in both the NIR emission of Yb3+ single ion and visible emission of Yb3+ pairs occurs, which is attributed to the reduction in impurities. (2) The annealing process induces new absorption bands in the ultraviolet-visible (UV-vis) region that increase as annealing temperature increases. These results suggest that reduction in Yb3+ to Yb2+ is taking place. The visible emission is considered to be a cooperative emission from Yb3+ pairs. Under UV and visible excitation, no emission of Yb2+ ions was observed. This suggests that the broadband absorption in the UV-vis region might be related to F color centers, which are responsible for the inhibition of the Yb2+ ion emission.
Modeling anisotropic damage in an encapsulated ceramic under ballistic impact
Authors: Zuo Q. H. , Dienes J. K. , Middleditch J. , Meyer H. W.
Published: July 2008

This paper presents a study of anisotropic damage and cracking in a hot isostatically pressed assembly of titanium alloy encapsulated AD-995 ceramic under ballistic impact using the statistical crack mechanics approach. Anisotropy of crack growth in the ceramic is illustrated numerically by examining the growth in crack sizes along three orientations. Comparisons with the experimental measurements of the predicted backsurface profile and the damage (cracking) in the ceramic suggest that the model predictions are consistent with the experimental data. Numerical simulation also indicates that a prestress of roughly 2kbar (200MPa) compensates for about 1% of initial porosity in the ceramic. A comparison is made to the Rajendran–Grove ceramic model in EPIC which assumes an isotropic crack distribution.
Room temperature electrical spin injection in remanence
Authors: Hövel S. , Gerhardt N. C. , Hofmann M. R. , Lo F.-Y. , Ludwig A. , Reuter D. , Wieck A. D. , Schuster E. , Wende H. , Keune W. , Petracic O. , Westerholt K.
Published: July 2008

We demonstrate electrical spin injection from ferromagnetic Fe/Tb multilayer structures with remanent perpendicular magnetization into GaAs-based light-emitting diodes at room temperature. Using a reverse-biased Schottky contact and a MgO tunnel contact, respectively, we achieve spin injection at remanence. The maximum degree of circular polarization of the emitted light is 3% at room temperature.
The language of higher education
Authors: Beecham Rod
Published: July 2008

Rhetoric, or persuasion, was recognised in classical times both as central to education and as dangerous when misused. Since the time of Kant, a feature of western thinking has been the creation of a special language to accompany a special idea. Making language prior to or separate
from its referents is of its nature an authoritarian activity. The managerialist language which surrounds us today threatens to reduce higher education to a managerialist endeavour, to replace conversation in the discipline with empty managerialist phrases, and to disguise the commonplace
in jargon. These are anti-educational manifestations which should be resisted.
Disempowering and dislocating: how learners from diverse cultures read the role of the English language in UK higher education
Authors: Welikala Thushari
Published: July 2008

This paper explores how the English language privileges and empowers certain epistemologies and ontologies in international higher education in the UK. The author discusses how the English language is used to construct assumptions and practices to legitimise particular ways of constructing
knowledge. The main argument is that language provides a lead in silencing and marginalising alternative forms of coming to know within diverse cultures, thus creating feelings of disempowerment and dislocation for some learners. The paper highlights how learners from different cultures make
sense of the role of language within the context of UK higher education, in terms of power, cultural politics and intellectual hegemony. It also suggests that ontological and epistemological stances are socially and culturally constructed, albeit reduced to linguistic constructions within
UK university contexts.
After the Philosophy of Mind: Replacing Scholasticism with Science*
Authors: Chemero Anthony , Silberstein Michael
Published: July 2008

We provide a taxonomy of the two most important debates in the philosophy of the cognitive and neural sciences. The first debate is over methodological individualism: is the object of the cognitive and neural sciences the brain, the whole animal, or the animal—environment system? The second is over explanatory style: should explanation in cognitive and neural science be reductionist-mechanistic, interlevel mechanistic, or dynamical? After setting out the debates, we discuss the ways in which they are interconnected. Finally, we make some recommendations that we hope will help philosophers interested in the cognitive and neural sciences to avoid dead ends.
Ignorance and Indifference*
Authors: Norton John D.
Published: July 2008

The epistemic state of complete ignorance is not a probability distribution. In it, we assign the same, unique, ignorance degree of belief to any contingent outcome and each of its contingent, disjunctive parts. That this is the appropriate way to represent complete ignorance is established by two instruments, each individually strong enough to identify this state. They are the principle of indifference (PI) and the notion that ignorance is invariant under certain redescriptions of the outcome space, here developed into the ‘principle of invariance of ignorance’ (PII). Both instruments are so innocuous as almost to be platitudes. Yet the literature in probabilistic epistemology has misdiagnosed them as paradoxical or defective since they generate inconsistencies when conjoined with the assumption that an epistemic state must be a probability distribution. To underscore the need to drop this assumption, I express PII in its most defensible form as relating symmetric descriptions and show that paradoxes still arise if we assume the ignorance state to be a probability distribution.
Backward flow in a surface tension driven micropump
Authors: Ju Jongil , Park Joong Yull , Kim Kyung Chun , Kim Hyundong , Berthier Erwin , Beebe David J , Lee Sang-Hoon
Published: July 2008

A surface tension driven micropump harnessing the pressure difference generated by drops of different curvature radii proves to be a simple and attractive passive method to drive fluid flow in microdevices. Here we observed the appearance of backward flow when the initial sizes of the droplets at the inlet and outlet ports are similar. To explain this phenomenon several hypotheses have been investigated. Consideration of the inertia of the fluid in the channel revealed that it alone is insufficient to explain the observed backward flow. We discovered that rotational flow inside the outlet droplet could be a source of inertia, explaining the generation of the backward flow. In addition, we have experimentally determined that the ratio of the volumes of the initial outlet drop and inlet drop correlates with the occurrence of the backward flow.