bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dihydroxyacetone‐induced death is accompanied by advanced glycation endproduct formation in selected proteins of Saccharomyces cerevisiae and Caenorhabditis elegans
Authors: Molin Mikael , Pilon Marc , Blomberg Anders 
Published: September 2007

AbstractAdvanced glycation endproduct (AGE) formation is an important mechanism for protein deterioration during diabetic complications and ageing. The effects on AGE formation following dihydroxyacetone (DHA) stress were studied in two model organisms, the yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans. Total protein AGEs, detected using an anti‐Nϵ‐carboxyalkyllysine‐specific monoclonal antibody, displayed a strong correlation to DHA‐induced yeast cell mortality in the wild‐type and hypersensitive as well as resistant mutant strains. During DHA‐induced cell death we also detected AGEs as the formation of acidic protein modifications by 2‐D PAGE. Furthermore, we confirmed AGE targets immunologically on 2‐D gel‐separated protein extracted from DHA‐treated cells. AGE modification of several metabolic enzymes (Eno2p, Adh1p, Met6 and Pgk1p) and actin (Act1p) displayed a strong correlation to DHA‐induced cell death. DHA was toxic to C. elegans even at low concentration and also in this organism AGE formation accompanied death. We propose the use of DHA as a model AGE‐generating substance for its apparent lack of a clear oxidative stress connection, and yeast and worm as model organisms to identify genetic determinants of protein AGE formation.
Static and shear induced crystallization of glass fiber reinforced poly(m‐xylylene adipamide) with nucleating additives
Authors: Naudy Sophie , Fulchiron René 
Published: September 2007

AbstractStatic and shear induced crystallization studies were carried out on a glass fiber reinforced poly(m‐xylylene adipamide) with various fiber contents. The crystallization experiments were performed using calorimetry and a shearing hot stage coupled with an optical microscope. The crystallization times were measured as a function of the temperature, the shear rate, and the fiber content. In static conditions, no nucleating ability of the fibers was highlighted. However, the shear treatment led to a substantial decrease of the crystallization times for all materials. Moreover, the shear effect is largely influenced by the fiber content, because the shear really undergone by the matrix between the fibers is locally higher than the nominal shear. A previously proposed crystallization kinetics model based on both Avrami and Hoffman–Lauritzen equations and taking into account the nucleating effect of the shear is improved. Hence, the fibers effect is included taking into account the higher local shear between the fibers. The nucleation rate due to the shear is described by a power law of the shear rate, where the prefactor is linked to the fibers amount. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2982–2992, 2007
Preparation and properties of the biodegradable graded blend of poly(L‐lactic acid) and poly(ethylene oxide)
Authors: Agari Yasuyuki , Sakai Kiyofumi , Kano Yosikazu , Nomura Ryoki 
Published: September 2007

AbstractWe prepared biodegradable poly(ethylene oxide) (PEO)/poly(L‐lactic acid) (PLLA) graded blends by the dissolution–diffusion process, and discussed the biodegradability and tensile strength of the graded blends by comparing isotropic blend and PLLA only. All the graded blends were degraded more largely than the PLLA only and isotropic blend (PEO: 37.5 wt %), which had the same content as the total content of those graded blends. The graded blend having most excellent wide compositional gradient was degraded most largely with the enzyme. Thus, graded structure of the blends promoted their biodegradabilities large. It was considered that the dissolution of PEO with water increased the surface area attacked by the enzyme, while PEO caught PLLA oligomers to promote the biodegradation of PLLA. Then, the biodegradabilities of the graded blends were suppressed by the increasing crystallinity of PLLA. Furthermore, the strengths of all the graded blends were larger than those of the isotropic blend. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2972–2981, 2007
Phase equilibrium and charge fractionation in polyelectrolyte solutions
Authors: Erukhimovich Igor , Olvera de la Cruz Monica 
Published: September 2007

AbstractA new type of phase separation in the polyelectrolyte solutions consisting of several types of charged macromolecules differing in their degree of ionization is presented. Via a general thermodynamic consideration we show that even a small difference in the degree of ionization of otherwise equivalent high‐molecular components results in their spatial separation occurring upon decreasing the temperature much earlier than precipitation of any of the pure components from the solution. Some implications of charge fractionation are discussed, including the separation of DNA (or RNA) strands interacting with different proteins and the appearance of heterogeneities in polyelectrolyte solutions of partially charged hydrophobic chains with polydispersed charge distributions such as sodium polystyrene sulfonate. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3003–3009, 2007
Electrical and Optical Properties of AC Microdischarges in Porous Ceramics
Authors: Hensel Karol , Martišovitš Viktor , Machala Zdenko , Janda Mário , Leštinský Michal , Tardiveau Pierre , Mizuno Akira 
Published: September 2007

AbstractGeneration of microdischarges inside porous ceramics by AC high voltage was explored. The physical properties of the microdischarges were investigated by electrical measurements, photographic visualization, and optical emission spectroscopy. The effects of pore size, discharge power, and gas mixture composition on the discharge properties and its development are described. The optimum generation and distribution of the microdischarges was observed with pore sizes of 50 and 80 µm. The emission spectra of the microdischarges indicated their strongly non‐equilibrium character. A theoretical analysis of the microdischarge mechanism is provided, accounting for the pore size and the elementary processes such as ionization, recombination, and ambipolar diffusion.
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Oropharyngeal aspiration and pneumonia in children
Authors: Weir Kelly , McMahon Sandra , Barry Linda , Ware Robert , Masters I Brent , Chang Anne B. 
Published: September 2007

AbstractOropharyngeal aspiration (OPA) of food and fluids is known to be associated with pneumonia in dysphagic children with neurological disease and direct causality is often assumed. However, little is known about the relationship between OPA and pneumonia in medically complex children when other possible risk factors for pneumonia are considered. We examined the association of World Health Organization (WHO)‐defined pneumonia in a heterogeneous group of children with swallowing dysfunction identified by a videofluoroscopic swallow study (VFSS). A retrospective chart review of 150 children (aged 2 weeks to 20 years) was undertaken to determine the relationship between pneumonia and (i) type of swallowing dysfunction (including OPA), (ii) consistency of aspirated food/fluid, and (iii) other factors including multisystem involvement and age (≤1 year or >1 year). In univariate analysis, the odds ratio (OR) for pneumonia was significantly increased in children with post‐swallow residue (PSR) (OR 2.5) or aspiration on thin fluids (OR 2.4), but not with aspiration of thick fluids or purees. In multi‐logistic regression, type of swallowing dysfunction or aspirated food/fluid were no longer significant. Instead, pneumonia was significantly associated with diagnosis of asthma (OR 13.25), Down syndrome (OR 22.10), gastroesophageal reflux disease (GERD) (OR 4.28), or history of LRTI (OR 8.28), moist cough (OR 9.17) or oxygen supplementation (OR 6.19). Children with multisystem involvement demonstrated a higher association with pneumonia, but no difference was found for age. We conclude that the impact of OPA on development of pneumonia is considerably reduced once other factors in children with multisystem involvement are taken into account. 2007;42:1024–1031. © 2007 Wiley‐Liss, Inc.
Topical, residual and ovicidal contact toxicity of three reduced‐risk insecticides against the European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), on potato
Authors: Boiteau Gilles , Noronha Christine 
Published: September 2007

AbstractBACKGROUND: The goal of the research was to gather efficacy data required to introduce reduced‐risk insecticides in sustainable control programs for European corn borer, Ostrinia nubilalis Hubner, on potato.RESULTS: Laboratory tests confirmed that sprays of indoxacarb and novaluron at recommended field rates are as effective as spinosad against neonate larvae of O. nubilalis. However, there is evidence that higher rates would enhance the inhibition of chitin synthesis by novaluron. The three insecticides showed ovilarvicidal activity when applied to O. nubilalis egg masses 2 days prior to black head stage. The ovicidal activity of spinosad and novaluron was almost twice that of indoxacarb. At the recommended field rates, the residues of the three insecticides displayed contact toxicity to O. nubilalis larvae. Spinosad residues 16 h old or less provided the highest immediate (24 h after exposure) contact mortality, followed by indoxacarb and then by novaluron. Also, residues of spinosad had faster contact efficacy than indoxacarb, which had faster efficacy than novaluron.CONCLUSION: Spinosad, indoxacarb and novaluron have ovicidal properties, which could enhance O. nubilalis management programs. However, the contact residual toxicity is limited in duration and would likely only play a minor role in O. nubilalis control. © Crown copyright 2007. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Reduced viability of Colorado potato beetle, Leptinotarsa decemlineata, eggs exposed to novaluron
Authors: Alyokhin Andrei , Sewell Gary , Choban Raymond 
Published: September 2007

AbstractBACKGROUND: Novaluron is a benzoylphenyl urea chitin synthesis inhibitor that combines good activity against larval stages of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), with low mammalian toxicity. Previous studies suggest that it has deleterious sublethal effects on adults.RESULTS: Continuous exposure of adult Colorado potato beetles to novaluron‐treated foliage as both ovipositional and feeding substrate did not affect their survivorship or the number of eggs produced, but viable larvae hatched only from the eggs that were laid on the first day of the experiment. Viability was restored after adult beetles spent 48–96 hours on untreated leaves. In a separate experiment, direct exposure to novaluron of eggs laid by unexposed beetles also reduced the number of larvae hatching.CONCLUSIONS: Results confirm a negative effect of novaluron on the number of progeny produced by the Colorado potato beetle. Direct toxicity did not explain all of the reduction in egg hatch observed, suggesting that novaluron probably acted on reproductive adults as well as on eggs after they were deposited. Copyright © 2007 Society of Chemical Industry
Backbone‐modified amylin derivatives: implications for amyloid inhibitor design and as template for self‐assembling bionanomaterials
Authors: Elgersma Ronald C. , Posthuma George , Rijkers Dirk T. S. , Liskamp Rob M. J. 
Published: September 2007

AbstractThis report reviews our approach to the design, synthesis and structural/morphological analysis of backbone‐modified amylin(20–29) derivatives. Depending on the position in the peptide backbone and the type of amide bond isostere/modification, the amylin(20–29) peptides behave either as inhibitors of amyloid fibril formation, which are able to retard amyloid formation of native amylin(20–29), or as templates for the formation of self‐assembled supramolecular structures. Molecular fine‐tuning of the hydrogen‐bond accepting/donating properties allows the control over the morphology of the supramolecular aggregation motifs such as helical ribbons and tapes, ribbons progressing to closed peptide nanotubes, (twisted) lamellar sheets or amyloid fibrils. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Structure‐guided design of peptidic ligand for human prostate specific antigen
Authors: Hassan MD Imtaiyaz , Kumar Vijay , Somvanshi Rishi K. , Dey Sharmistha , Singh Tej P. , Yadav Savita 
Published: September 2007

AbstractProstate specific antigen (PSA) is a member of kallikrein family having serine protease‐like activity and acts as a prognostic marker of prostate carcinoma. Various studies have been performed on inhibition of PSA and such targeting requires the identification of highly selective peptide inhibitors. PSA was purified from human seminal plasma by rapid and efficient methods, and binding studies for various peptides were carried out by fluorescence spectroscopy and SPR. The ‘S’ of PSA is predominated by hydrophobic residues, and hence many hydrophobic peptides were used to determine their binding affinity to PSA by fluorescence spectroscopy. We observed that LLFW, FFKW, and KFW binds strongly to PSA, among them LLFW showed strong binding. SPR also showed strong binding affinity of PSA toward peptides with hydrophobic and basic residues. Among the peptides used, FWYS showed dramatic increase in binding affinity (10−10 M). The peptides analyzed for binding studies, suggests that peptide with Trp residue along with basic or hydrophobic amino acids may be useful for designing specific inhibitors for PSA. The strong affinities of designed peptides for PSA can be a valuable tool for designing therapeutic agents for prostate carcinomas. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Fast conventional Fmoc solid‐phase peptide synthesis with HCTU
Authors: Hood Christina A. , Fuentes German , Patel Hirendra , Page Karen , Menakuru Mahendra , Park Jae H. 
Published: September 2007

Abstract1H‐Benzotriazolium 1‐[bis(dimethyl‐amino)methylene]‐5‐chloro‐hexafluorophosphate (1‐),3‐oxide (HCTU) is a nontoxic, nonirritating and noncorrosive coupling reagent. Seven biologically active peptides (GHRP‐6, 65–74ACP, oxytocin, G‐LHRH, C‐peptide, hAmylin1–37, and β‐amyloid1–42) were synthesized with reaction times reduced to deprotection times of 3 min or less and coupling times of 5 min or less using HCTU as the coupling reagent. Expensive coupling reagents or special techniques were not used. Total peptide synthesis times were dramatically reduced by as much as 42.5 h (1.8 days) without reducing the crude peptide purities. It was shown that HCTU can be used as an affordable, efficient coupling reagent for fast Fmoc solid‐phase peptide synthesis. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Appearance of ferroelectricity in thin films of incipient ferroelectric
Authors: Eliseev E. A. , Glinchuk M. D. , Morozovska A. N. 
Published: September 2007

AbstractThe consideration of a size‐induced ferroelectric–paraelectric phase transition for conventional and incipient ferroelectric thin films with perovskite structure was carried out in the phenomenological theory framework of Ginsburg–Landau–Devonshire. The more general form of surface free energy expansion that includes intrinsic surface stress tensor, the surface piezoelectric effect and electrostriction as well as quadratic and quartic powers of surface polarization has been considered. The analytical expressions for the thickness dependence of the transition temperature was derived both for the conventional and incipient ferroelectrics. It was shown that although there is no ferroelectricity in the bulk incipient ferroelectrics it appears in thin film for the negative extrapolation length that is realized, e.g., at positive surface stress coefficients and negative or zero misfit strain. In our consideration we came to the conclusion about thickness‐induced ferroelectricity in incipient ferroelectrics KTaO3 at room temperature for films that were sufficiently thin. The similar surface effects can strongly influence the phase transitions in the thin films of another incipient ferroelectric, SrTiO3. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive finite element method for simulation of optical nano structures
Authors: Pomplun Jan , Burger Sven , Zschiedrich Lin , Schmidt Frank 
Published: September 2007

AbstractWe discuss realization, properties and performance of the adaptive finite element approach to the design of nano‐photonic components. Central issues are the construction of vectorial finite elements and the embedding of bounded components into the unbounded and possibly heterogeneous exterior. We apply the finite element method to the optimization of the design of a hollow core photonic crystal fiber. Thereby we look at the convergence of the method and discuss automatic and adaptive grid refinement and the performance of higher order elements. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Perfectly matched layer method in the finite‐difference time‐domain and frequency‐domain calculations
Authors: Shyroki D. M. , Lavrinenko A. V. 
Published: September 2007

AbstractA complex‐coordinate method known under the guise of the perfectly matched layer (PML) method for treating unbounded domains in computational electrodynamics is related to similar techniques in fluid dynamics and classical quantum theory. It may also find use in electronic‐structure finite‐difference simulations. Straightforward transfer of the PML formulation to other fields does not seem feasible, however, since it is a unique feature of electrodynamics – the natural invariance – that allows analytic trick of complex coordinate scaling to be represented as pure modification of local material parameters within thin layers of space adjacent to the computational domain boundaries, i.e., the PMLs. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Krylov‐subspace based solver for the linear and nonlinear Maxwell equations
Authors: Busch Kurt , Niegemann Jens , Pototschnig Martin , Tkeshelashvili Lasha 
Published: September 2007

AbstractWe describe an efficient Krylov‐subspace based operator‐exponential approach for solving the Maxwell equations. This solver exhibits excellent stability properties and high‐order time‐stepping capabilities that allow to address nonlinear wave propagation phenomena and/or coupled system dynamics. Furthermore, the usage of a non‐uniform spatial grid facilitates the realization of a high‐order spatial discretization in the presence of discontinuous material properties. This ideally complements the time‐stepping capabilities of our solver so that complex nano‐photonic problems may be treated with high accuracy and efficiency. We illustrate these features through an analysis of the prototypical problem of spontaneous emission from a collection of two‐level atoms that are embedded in finite Photonic Crystals and are exposed to dephasing as well as non‐radiative decay processes. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Breakdown of the adiabatic approximation in a doped graphene monolayer and in metallic carbon nanotubes
Authors: Lazzeri Michele , Saitta A. Marco , Mauri Francesco 
Published: September 2007

AbstractWe compute, from first‐principles, the frequency of the phonons associated to the Raman G‐bands in a graphene monolayer and in metallic nanotubes as a function of the charge doping. In both cases, the frequency displays an important measurable shift in the range of doping reached experimentally. As a consequence, Raman spectroscopy can be used as a direct probe of the doping of these systems. Calculations are done using (i) the adiabatic Born–Oppenheimer approximation and (ii) time‐dependent perturbation theory to explore dynamic effects beyond this approximation. The two approaches provide very different results. The frequency shift of the G‐band in graphene and of the G– in metallic tubes represent remarkable failures of the adiabatic Born–Oppenheimer approximation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of multiwall boron nitride nanotubes
Authors: Jaffrennou P. , Barjon J. , Lauret J.‐S. , Maguer A. , Golberg D. , Attal‐Trétout B. , Ducastelle F. , Loiseau A. 
Published: September 2007

AbstractOptical properties of multiwall boron nitride nanotubes are investigated by means of luminescence and absorption spectroscopies. Cathodoluminescence imaging shows that boron nitride nanotubes are highly UV luminescent materials and that the luminescence is located all along the nanotube. In comparison with the related bulk material, hexagonal boron nitride, luminescence and absorption experiments point out the role of excitonic effects in this nanoobject. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equilibrium and non‐equilibrium optical properties of MoSI nanowires
Authors: Gadermaier C. , Kusar P. , Vengust D. , Vilfan I. , Mihailovic D. 
Published: September 2007

AbstractThe optical absorbance of oriented Mo6S3I6 nanowire thin films is measured and compared to spectra calculated using density functional theory. The expected sharp Van Hove singularities in the optical absorption spectra are not observed, partly because of the large density of interpenetrating electron sub‐bands and partly due to damping and disorder. Using femtosecond pump–probe spectroscopy we have measured the reflection of an optical pulse from a propagating acoustical disturbance in a randomly formed Mo6S3I6 nanowire network. This allows us to determine the sound velocity in a highly damped medium, which is not measurable by other techniques. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Single‐walled carbon nanotube silica composites obtained by an inorganic sol–gel route
Authors: Jung de Andrade M. , Lima M. Dias , Stein L. , Pérez C. , Roth S. 
Published: September 2007

AbstractIn the present work we first report on a successful incorporation of single‐walled carbon nanotubes (SWCNTs) into silica matrix prepared using an inorganic sol–gel method. Through this route non‐aqueous solvents are avoided and the stability of the carbon nanotubes suspensions is not affected. SWCNTs produced by Catalytic Chemical Vapor Deposition (CCVD) were dispersed in deionized water using an amphilic surfactant. As a precursor for the silica matrix an inexpensive silicic acid was used. By this route SWCNTs/silica composites were produced in the form of films and pellets. Microhardness measurements and electron microscopy suggest an important interaction between SWCNTs and the silica matrix what is important from the application point of view. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman spectroscopy on chemically functionalized carbon nanotubes
Authors: Müller M. , Maultzsch J. , Wunderlich D. , Hirsch A. , Thomsen C. 
Published: September 2007

AbstractWe present Raman spectroscopy on carbon nanotubes, functionalized with alkyl groups to different degrees and with different addition reactions. We observe effects in particular on the intensities of the radial breathing mode (RBM). From the RBM we can assign the diameter and chiral indices of the tubes and study the influence of functionalization on different tubes, their transition energies, Raman shifts and RBM intensities. We observe a diameter dependence of the chemical reaction under certain reaction conditions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Six‐fold rotationally symmetric vanadium oxide nanostructures by a morphotropic phase transition
Authors: O'Dwyer C. , Lavayen V. , Fuenzalida D. , Newcomb S. B. , Santa Ana M. A. , Benavente E. , González G. , Sotomayor Torres C. M. 
Published: September 2007

AbstractIn this work, we report the first observation of unique hierarchical six‐fold rotational symmetrical vanadium oxide based nanocomposite synthesized by a simple chemical route and highlight the first observation of a morphotropic reconstructive phase transistion from a lamellar V2O5 to that of a single crystalline V6O11 nanostructure. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)