bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neural models for the V‐shaped conductor‐backed coplanar waveguides
Authors: Guney Kerim , Yildiz Celal , Kaya Sabri , Turkmen Mustafa 
Published: March 2007

AbstractNeural models based on the artificial neural networks (ANNs) for computing the effective permittivities and characteristic impedances of V‐shaped conductor‐backed coplanar waveguides are presented. The proposed neural models can also be used for calculating the characteristic parameters of conductor‐backed coplanar waveguides. Six learning algorithms, Levenberg–Marquardt, bayesian regularization, quasi–Newton, scaled conjugate gradient, conjugate gradient of Fletcher‐Reeves, and resilient propagation, are used to train the ANNs. The neural results are in very good agreement with the results available in the literature. When the performances of neural models are compared with each other, the best result is obtained from the ANNs trained by the LM algorithm. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1294–1299, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22473
Investigation of the performance of L‐band EDFAS with single forward pumping schemes
Authors: Liang Tsair‐Chun , Huang Hsi‐Shan 
Published: March 2007

AbstractIn this article, the authors investigate and compare the gain and noise figure of various 1480‐nm pumping erbium‐doped fiber amplifier configurations to amplify 32 digital wavelength division multiplexing channel signals operated in the long‐wavelength band of 1570–1610 nm. It was found that the two‐stage designs are better than one‐stage design to offer the higher output power and gain with moderate low noise figure in single forward pumping scheme. Especially, the two‐stage double‐pass configuration, Type A, provides gain enhancement more than about 5.4 dB without paying any noise penalty. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1259–1261, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22475
Solid‐state 13C NMR and quantum chemical investigation of metal diene complexes
Authors: Ma Zhiru , Facelli Julio C. , Pugmire Ronald J. , Dunn Brian C. , Turpin Gregory C. , Eyring Edward M. , Ernst Richard D. 
Published: March 2007

AbstractThis paper presents novel measurements and calculations of the olefinic 13C chemical shift tensor principal values in several metal diene complexes. The experimental values and the calculations show shifts as large as 70 ppm with respect to the values in the parent olefinic compounds. These shifts are highly anisotropic, with the largest ones observed in the less shielded principal components and the smallest ones in the most shielded principal components of the tensor. The orientations of the principal components of the tensors remain, within 10°, at their directions in ethylene and other olefinic compounds. The calculations, performed using the GIAO method and the LanDZ pseudopotential basis set, show good agreement with the experiments, and were used to establish definite evidence for the existence of a Cl‐bridge structure in the bicyclo[2.2.1]hepta‐2,5‐diene (BCHD)dichlororuthenium(II) polymer. Copyright © 2007 John Wiley & Sons, Ltd.
Two‐dimensional spectroscopy with parallel acquisition of 1HX and 19FX correlations
Authors: Kupče Eriks , Cheatham Steve , Freeman Ray 
Published: March 2007

AbstractTwo‐dimensional NMR spectra correlating both 1H and 19F nuclei with either 13C or 15N, are recorded at the same time, using a 600‐MHz broadband radio frequency probe feeding independent 1H and 19F receiver channels. This technique, known as parallel acquisition NMR spectroscopy (PANSY), speeds up multidimensional NMR and is compatible with other fast‐acquisition schemes. The method is illustrated with single‐bond (HSQC) and multiple‐bond (HMBC) experiments on 2‐bromophenyl‐3‐trifluoromethyl‐5‐methylpyrazole, giving simultaneous 1HX and 19FX correlation spectra (X = 13 C or 15N). Copyright © 2007 John Wiley & Sons, Ltd.
Machiavelli, marketing and management: ends and means in public affairs
Authors: Harris Phillip 
Published: March 2007

Abstract

Niccolo Machiavelli is introduced and used as a guide to some of the key issues facing modern business and government. Machiavelli's morality and philosophy is explored and reflected upon. Insights into the realities of power and decision making are used to reflect on the emergence of the modern public affairs industry. Key lessons are suggested for success.

Copyright © 2007 John Wiley & Sons, Ltd.
Lobbying and the 2006 U.S. midterm elections
Authors: McGrath Conor 
Published: March 2007

Abstract

Lobbyists are inextricably intertwined with the electoral process in the United States, but rarely have they ever featured so prominently in an election year as in 2006. The midterm elections came at the end of a year in which the political news was often dominated by stories of lobbying scandal, most notably that involving Jack Abramoff. Lobbying was an important issue in many peoples' voting decisions, and moreover one of the immediate outcomes of the election was a raft of lobbying reform measures both in Congress and in the individual states. As one commentator put it: ‘For lobbyists, 2006 rolled by like a late‐night B movie where the earthquake wipes out the villagers who refused to heed the warning signs’ (Divis, 2006). This article reviews some of the most substantial lobbying scandals which emerged during 2006, considers how lobbying and lobbyists fared during the election campaigns, and analyses the various reforms which have recently been considered and implemented, before briefly examining how lobbyists will impact upon the 2008 election races.

Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of heterogeneity by sedimentation transport: Concentration and pressure effects
Authors: Atkinson Carole M. L. , Dietz Roy 
Published: March 2007

AbstractA new approach to the pressure dependence of sedimentation was applied to polystyrene in cyclohexane under conditions, below the theta‐temperature, where the concentration dependence is small. An expression for the distribution of sedimentation coefficient was derived, and used to find molecular weight distributions of standard samples; comparisons were made with molecular weight distributions found independently.
Factors affecting the elimination of hydrogen fluoride from a vinylidene fluoride/hexafluoropropene/tetrafluoroethylene terpolymer
Authors: Wright W. W. 
Published: March 2007

AbstractThe evolution of hydrogen fluoride from a vinylidene fluoride/hexafluoro‐propene/tetrafluoroethylene elastomer has been studied over the temperature range 200–275 °C in air. The rate of evolution is affected by the diamine curing agent, the carbon black filler and the acid acceptor used and their effects are interrelated. The acid acceptor also influences the crosslink density attained in the curing process. It was found that some metallic hydroxides and carbonates, in whose presence an acceptable level of crosslinking was achieved, were some 50 to 100 times more efficient than the magnesium oxide normally used in reducing the rate of hydrogen fluoride evolution.
Kinetic study of the formation of 1,1‐Diphenyl ethylene dimer dianions
Authors: Adams David J. , Clifton James , Gordon Manfred , Iguchi M. 
Published: March 2007

AbstractThe reaction between styrene or a styrene derivative and an alkali metal is the first stage in the synthesis of regular copolymers. The kinetics of the reaction of 1,1‐diphenyl ethylene in tetrahydrofuran at a sodium metal surface has been studied using a rotating sodium disc. It has been established that the reaction is transport controlled and first order in 1,1‐diphenyl ethylene concentration.
Correlation between morphology and stress—strain properties of three block copolymers i. stress‐softening effect
Authors: Pedemonte Enrico , Turturro Antonio , Dondero Giovanni 
Published: March 2007

AbstractThe stress‐softening effect, which comes out when SBS three block copolymers are stretched, is taken into consideration and the conclusion is reached that it is due to a disruption of the polystyrene continuous phase, according to the hypothesis of other authors. This conclusion is supported by two kinds of experiments performed on samples having a well known and simple morphology. First of all by stress‐strain measurements on specimens previously swollen: it can be seen that the stress‐softening effect disappears as soon as the structure of the material is completely modified by the treatment. Secondly by the direct observation at the electron microscope of the structure after the deformation. This shows how the original continuous and regular polystyrene rods of the “single crystal” assume a string of pearl structure which finally is irreversibly disrupted.
Experiences with the method of trimethylsilylation for the study of soluble silicates
Authors: Glasser Lesley S. Dent , Sharma Santosh K. 
Published: March 2007

AbstractIt is possible to prepare organic derivatives of silicate groups in which each terminal oxygen is blocked by a trimethylsilyl group. This can provide a route for the preparation of new polymers. It can also provide information about the structure of the original silicate group, provided that this is faithfully reflected in the structure of the derivative. This will be true only if the silicate groups do not undergo any polymerisation, depolymerisation or rearrangement while the derivatives are being formed.The method has previously been successfully applied to a wide variety of silicates; this paper describes, in particular, attempts to apply it to the study of sodium silicates. An assessment is given of the difficulties involved and of the utility of the method for this type of study.
Titration curves of p‐hydroxybenzoic acid/formaldehyde/p‐bromophenol copolymers
Authors: Chatterjee S. K. , Dattagupta N. 
Published: March 2007

AbstractCopolymers obtained by the condensation of p‐hydroxybenzoic acid, p‐bromophenol, and formaldehyde showed characteristic titration curves in non‐aqueous media. The titration curves indicated a series of breaks which bear integral relations to each other. These features have been interpreted in terms of homoconjugation, intramolecular hydrogen bond formation, and composition of the copolymers.
Phosphorescence from commercial polyolefins and polyamides: Effects of thermal and photochemical oxidation
Authors: Allen N. S. , Homer J. , McKellar J. F. , Phillips G. O. 
Published: March 2007

AbstractA study of the phosphorescence emission from the commercial polyolefins, polyethylene, polypropylene and poly‐4‐methylpentene‐1 and the polyamides, nylon 6/6, 6, 11 and 12 is presented and the origin of the emission discussed. Impurity centres in the polymer are responsible for the emission, being present either as groups directly attached to the polymer backbone or as discrete molecules within the polymer matrix. These impurities can play an important part in the thermal and photochemical oxidation of the polymer. Therefore, changes in the phosphorescence spectra can provide valuable information on the mechanisms of both degradation processes.
Crosslinking of latex polymers
Authors: Yeliseeva Valentina I. 
Published: March 2007

AbstractThe physicomechanical properties and processes of thermal crosslinking of latex acrylic polymer films containing functional groups of different chemical nature were studied. Improvement of properties characteristic of latex copolymers containing methylolamide groups is explained by orientated location of hydrophilic groups on the surface of latex particles during emulsion copolymerisation, that, in its turn, leads to a more ordered arrangement of macrochains. An optimum content of methylolamide groups as regards crosslinking processes was established and explained by steric location of these groups on the surfaces of latex particles. A similar optimum is not observed for crosslinking by watersoluble resin of latex copolymers containing groups of hydrophobic glycidylmethacrylate.
Luminescence studies of polymer behaviour
Authors: North Alastair M. 
Published: March 2007

AbstractLuminescence techniques can be used to study polymer systems both as an analytical tool and as a means of studying molecular behaviour. In the latter context, some very interesting information may be obtained on a variety of molecular and energy transport processes. Measurements of luminescence intensity and quenching can be used to observe electronic energy transfer processes (both along polymer chains and from polymer chains to additive molecules). These have a technical importance in that they are the photophysical processes which precede the chemical phenomena important in photodegradation or photostabilisation of polymers. The basic criteria for energy transfer are introduced and examples are given of “down‐chain” energy migration coefficients for a number of polymers. Studies of the depolarisation of luminescence can be used as a measurement of rotation in the electronic excited state of the photoactive group. Fluorescence depolarisation is introduced and examples are given of processes with nanosecond relaxation times. The concept of phosphorescence depolarisation is also mentioned, and the first use of this to study processes with millisecond relaxation times is illustrated.
Self‐association in {2‐[3,4‐alkylenedioxy‐5‐(3‐pyridyl)]‐thienyl}alkanols: an NMR, IR, and single‐crystal X‐ray study
Authors: Lomas John S. , Cordier Christine , Adenier Alain , Maurel François , Vaissermann Jacqueline 
Published: March 2007

Abstractsyn‐2,2,4,4‐Tetramethyl‐3‐{2‐[3,4‐alkylenedioxy‐5‐(3‐pyridyl)]thienyl}pentan‐3‐ols self‐associate both in the solid state and in solution. Single‐crystal X‐ray diffraction study of the 3,4‐ethylenedioxythiophene (EDOT) derivative shows that it exists as a centrosymmetric head‐to‐tail, syn dimer in the solid state. The IR spectra of the solids display only a broad OH absorption around 3300 cm−1, corresponding to a hydrogen‐bonded species. 1H Nuclear Overhauser Effect Spectroscopy (NOESY) NMR experiments in benzene reveal interactions between the tert‐butyl groups and the H2 and H6 protons of the pyridyl group. Two approaches have been used to determine association constants of the EDOT derivative by NMR titration, based on the concentration dependence of (i) the syn/anti ratio and (ii) the OH proton shift of the syn rotamer. Reasonably concordant results are obtained from 298 to 323 K (3.6 and 3.9 M−1, respectively, at 298 K). Similar values are obtained from the syn OH proton shift variation for the 3,4‐methylenedioxythiophene (MDOT) derivative. Concentration‐dependent variation of the anti OH proton shift in the latter suggests that the anti isomer associates in the form of an open, singly hydrogen‐bonded dimer, with a much smaller association constant than the syn rotamer. Self‐association constants for 3‐pyridyl‐EDOT‐alkanols with smaller substituents vary by a factor of 4 from (i‐Pr)2 up to (CD3)2, while the hetero‐association constants for the same compounds with pyridine vary slightly less. Copyright © 2007 John Wiley & Sons, Ltd.
Growth deceleration of children on inhaled corticosteroids is compensated for after the first 12 months of treatment
Authors: Anthracopoulos Michael B. , Papadimitriou Anastasios , Panagiotakos Demosthenes B. , Syridou Garyfalia , Giannakopoulou Eleni , Fretzayas Andrew , Nicolaidou Polyxeni , Priftis Kostas N. 
Published: March 2007

AbstractTiming and duration of linear growth suppression in children on long‐term inhaled corticosteroids (ICS) are not entirely clear; we undertook a “pragmatic” study to determine growth of asthmatic children on long‐term ICS managed by a flexible dosing step‐down approach. Standard deviation scores of height (HSDS), height velocity (HVSDS), and body mass index (BMISDS) of pre‐pubertal asthmatic children on maintenance therapy with either budesonide (BUD) or fluticasone propionate (FP) were calculated in a prospective open‐label non‐randomized study. Outcomes were recorded at initiation of ICS, 6, 12, 24, and 36 months, as applicable, and 6 months after ICS treatment discontinuation. Three hundred twenty‐two children on BUD and 319 on FP were enrolled after the completion of 6‐month treatment. The median (range) daily dose at initiation was 400 mcg (400–1,200) and 200 mcg (200–500), the final maintenance 200 mcg (200–400) and 100 mcg (100–200), respectively. In the first 6–12 months, a decrease in HSDS of approximately 18% below baseline values was noted (P < 0.01) that was restored to almost baseline average levels by 24 months, and slightly increased to above baseline during the third year. HVSDS showed a linear increase in both treatment arms (P < 0.01). No differences were found between the two treatment arms regarding HSDS, HVSDS, and BMISDS at any time point over the course of the study. In conclusion, growth deceleration of asthmatic children on maintenance ICS is compensated for after the first 12 months of treatment. This effect does not differ between BUD and FP treatment, despite some variation in the pattern of linear growth. Pediatr Pulmonol. 2007; 42:465–470. © 2007 Wiley‐Liss, Inc.
A small chimeric promoter for high prostate‐specific transgene expression from adenoviral vectors
Authors: Kraaij Robert , van der Weel Laura , de Ridder Corrina M.A. , van der Korput Hetty A.G.M. , Zweistra Joke L.M. , van Rijswijk Angélique L.C.T. , Bangma Chris H. , Trapman Jan 
Published: March 2007

AbstractBACKGROUNDSpecificity of transgene expression is important for safety during gene therapeutical applications. For prostate cancer, transcriptional targeting has been applied but was hampered by loss of specificity and low activity. We constructed a small chimeric promoter for high and prostate‐specific transgene expression from adenoviral vectors.METHODSA chimeric promoter, composed of the prostate‐specific antigen (PSA) enhancer and the rat probasin promoter, was cloned into an adenoviral vector and its activity was compared to vectors containing conventional prostate‐specific promoters and the constitutive Cytomegalovirus (CMV) promoter in in vitro and in vivo prostate cancer models.RESULTSThe chimeric PSA‐probasin promoter was the most active prostate‐specific promoter reaching up to 20% of CMV promoter activity while maintaining prostate‐specificity.CONCLUSIONSThe chimeric PSA‐probasin promoter is a small promoter that can be utilized in viral vectors for high prostate‐specific transgene expression. Prostate 67: 829–839, 2007. © 2007 Wiley‐Liss, Inc.
Mass spectrometric identification of the trypsin cleavage pathway in lysyl‐proline containing oligotuftsin peptides
Authors: Manea Marilena , Mező Gábor , Hudecz Ferenc , Przybylski Michael 
Published: March 2007

AbstractTrypsin cleaves specifically peptide bonds at the C‐terminal side of lysine and arginine residues, except for ‐Arg‐Pro‐ and ‐Lys‐Pro‐ bonds which are normally resistant to proteolysis. Here we report evidence for a ‐Lys‐Pro‐ tryptic cleavage in modified oligotuftsin derivatives, Ac‐[TKPKG]4‐NH2) (1), using high‐resolution mass spectrometry and HPLC as primary methods for analysis of proteolytic reactions. The proteolytic susceptibility of ‐Lys‐Pro‐ bonds was strongly dependent on flanking residues, and the flexibility of the peptide backbone might be a prerequisite for this unusual cleavage. While ‐Lys‐Gly‐ bonds in 1 were rapidly cleaved, the modification of these Lys residues by the attachment of a ß‐amyloid(4–10) epitope to yield ‐Lys(X)‐Gly derivatives prevented cleavage of this bond, and provided trypsin cleavage of ‐Lys‐Pro‐ bonds, the pathway of this degradation being independent on the type of Lys‐Nε‐side chains (acetyl group, amino acid, peptide). Substitution of the Lys residues by Ala at the P′2 positions decreased the tryptic cleavage, while replacement of the bulky side chain of Thr at the P2 positions strongly increased the cleavage of ‐Lys‐Pro‐ bonds. Circular dichroism (CD) data of the modified oligotuftsin derivatives are in accord with enhanced flexibility of the peptide backbone, as a prerequisite for increased susceptibility to cleavage of ‐Lys‐Pro‐ bonds. These results obtained of oligotuftsin derivatives might have implications for the proteolytic degradation of target peptides that require specific conformational preconditions. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Induction of macrophage migration through lactose‐insensitive receptor by elastin‐derived nonapeptides and their analog
Authors: Maeda Iori , Mizoiri Noriaki , Briones Maria Portia P. , Okamoto Kouji 
Published: March 2007

AbstractElastin, one of the extracellular matrix components, is present in tissues requiring extensibility and resilience such as the aorta, lungs, ligaments and skin. Degradation of elastin is observed in diseases such as atherosclerosis, emphysema and metastasis. It has been suggested that degraded elastin‐derived peptides interact with a variety of cell types and are involved in development of diseases. Two nonapeptides, Ala‐Gly‐Val‐Pro‐Gly‐Leu‐Gly‐Val‐Gly (AGVPGFGVG) and Ala‐Gly‐Val‐Pro‐Gly‐Phe‐Gly‐Val‐Gly (AGVPGFGVG), exist in hydrophobic regions of elastin. In this paper, we characterized these elastin‐derived nonapeptides by macrophage migration assay. Both nonapeptides induced a maximal migration at 10−8 M and elicited the same degree of responsiveness. To investigate the role of the sixth residue of the nonapeptides, seven analog peptides in which Leu or Phe is substituted by Ile, Val, Ala, Gly, Pro, Lys or Glu were synthesized and their macrophage migration activity tested. Among the nonapeptide analogs, only Ala‐Gly‐Val‐Pro‐Gly‐Ile‐Gly‐Val‐Gly induced the migration of macrophages at the optimal concentration of 10−9 M and its responsiveness was the same as that of parent nonapeptide AGVPGFGVG. Results of the deactivation tests and the effect of lactose on macrophage migration showed that a lactose‐insensitive receptor which mainly recognizes Ala‐Gly‐Val‐Pro‐Gly‐Ile‐Gly‐Val‐Gly is presumably present on the membrane of macrophages in addition to the elastin‐binding protein (EBP) sensitive to lactose. These results suggest that Leu, Phe and Ile residues at the sixth position of elastin‐derived nonapeptides are crucial for inducing macrophage migration and in particular, Ile residue is important for the recognition by receptor insensitive to lactose. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
The solution structure of horseshoe crab antimicrobial peptide tachystatin B with an inhibitory cystine‐knot motif
Authors: Fujitani Naoki , Kouno Takahide , Nakahara Taku , Takaya Kenji , Osaki Tsukasa , Kawabata Shun‐ichiro , Mizuguchi Mineyuki , Aizawa Tomoyasu , Demura Makoto , Nishimura Shin‐Ichiro , Kawano Keiichi 
Published: March 2007

AbstractTachystatin B is an antimicrobial and a chitin‐binding peptide isolated from the Japanese horseshoe crab (Tachypleus tridentatus) consisting of two isopeptides called tachystatin B1 and B2. We have determined their solution structures using NMR experiments and distance geometry calculations. The 20 best converged structures of tachystatin B1 and B2 exhibited root mean square deviations of 0.46 and 0.49 Å, respectively, for the backbone atoms in Cys4‐Arg40. Both structures have identical conformations, and they contain a short antiparallel β‐sheet with an inhibitory cystine‐knot (ICK) motif that is distributed widely in the antagonists for voltage‐gated ion channels, although tachystatin B does not have neurotoxic activity. The structural homology search provided several peptides with structures similar to that of tachystatin B. However, most of them have the advanced functions such as insecticidal activity, suggesting that tachystatin B may be a kind of ancestor of antimicrobial peptide in the molecular evolutionary history. Tachystatin B also displays a significant structural similarity to tachystatin A, which is member of the tachystatin family. The structural comparison of both tachystatins indicated that Tyr14 and Arg17 in the long loop between the first and second strands might be the essential residues for binding to chitin. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.