bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Determination of a Photochemically Active Diplatinum Molecule by Time‐Resolved EXAFS Spectroscopy
Authors: van der Veen Renske M. , Milne Chris J. , El Nahhas Amal , Lima Frederico A. , Pham Van‐Thai , Best Jonathan , Weinstein Julia A. , Borca Camelia N. , Abela Rafael , Bressler Christian , Chergui Majed
Published: March 2009

Metallica: A large contraction of the PtPt bond in the triplet excited state of the photoreactive [Pt2(P2O5H2)4]4− ion is determined by time‐resolved X‐ray absorption spectroscopy (see picture). The strengthening of the PtPt interaction is accompanied by a weakening of the ligand coordination bonds, resulting in an elongation of the platinum–ligand bond that is determined for the first time.

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Organisation of the Biosynthetic Gene Cluster and Tailoring Enzymes in the Biosynthesis of the Tetracyclic Quinone Glycoside Antibiotic Polyketomycin
Authors: Daum Martina , Peintner Iris , Linnenbrink Anton , Frerich Anke , Weber Monika , Paululat Thomas , Bechthold Andreas
Published: March 2009

Surprising results regarding the function of methyltransferases and oxygenases: Investigations on oxygenase and methyltransferase genes that are located in the polyketomycin biosynthetic gene cluster of Streptomyces diastatochromogenes Tü6028 shed light into polyketide‐modifying reactions.

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Polyketomycin is a tetracyclic quinone glycoside produced by Streptomyces diastatochromogenes Tü6028. It shows cytotoxic and antibiotic activity, in particular against Gram‐positive multi‐drug‐resistant strains (for example, MRSA). The polyketomycin biosynthetic gene cluster has been sequenced and characterised. Its identity was proven by inactivation of a α‐ketoacyl synthase gene (pokP1) of the “minimal polyketide synthase II” system. In order to obtain valuable information about tailoring steps, we performed further gene‐inactivation experiments. The generation of mutants with deletions in oxygenase genes (pokO1, pokO2, both in parallel and pokO4) and methyltransferase genes (pokMT1, pokMT2 and pokMT3) resulted in new polyketomycin derivatives, and provided information about the organisation of the biosynthetic pathway.
Subcritical Water Reaction Behavior of D‐Glucose as a Model Compound for Biomass Using Two Different Continuous‐Flow Reactor Configurations
Authors: Saito T. , Sasaki M. , Kawanabe H. , Yoshino Y. , Goto M.
Published: March 2009

Recently, cellulosic materials have been considered as a useful resource for the recovery of valuable chemicals and liquid fuels, etc. Cellulose is a homopolymer of D‐glucose, which is often used as a model compound for biomass. Reactions of D‐glucose in subcritical water as the reaction solvent were conducted using a single‐flow‐type reactor (S1) and an admixture‐type reactor with feed and preheated‐water flow (S2) at temperatures from 200 to 240 °C, pressures from 15 to 20 MPa, residence times from 40 to 120 s, and initial feed concentrations of 1.5–10 wt %. D‐Glucose was converted into aldehydes, organic acids and furans, with mainly organic acids obtained at 240 °C. D‐Glucose decomposition using reactors S1 and S2 revealed that the conversion rate of D‐glucose was promoted more using S2 than by S1. The yield of furans with S1 was higher than with S2, while the yield of organic acids from S1 was lower than that from S2.
Linker Conjugation Effects in Rhenium(I) Bifunctional Hole‐Transport/Emitter Molecules
Authors: Cleland Deidre M. , Irwin Garth , Wagner Pawel , Officer David L. , Gordon Keith C.
Published: March 2009

Interchromophoric communication– when darkness falls: This study investigates the electronic communication between various hole‐transporting (HT) ligands and a rhenium(phenanthroline) centre to which they are coordinated. It is found that when the conjugation within the HT ligand is increased, the energy of a non‐emissive HT ligand electronic transition is sufficiently lowered so that it interacts with, and partially deactivates, emission from the rhenium(phenanthroline) moiety (see figure).

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Spectroscopic, electrochemical and density functional theory (DFT) methods have been employed to investigate a group of [Re(CO)3(HT)(phen)]+ complexes (phen=1,10‐phenanthroline), and in particular the level of electronic communication between various hole‐transporting (HT) ligands and the rhenium centre. Here, the HT ligand consists of a coordinating pyridine connected to dimethylaniline group through a single‐, double‐ or triple‐bond‐connecting system. Electronic absorption, resonance Raman, and steady‐state emission spectroscopy combined with lifetime studies and DFT calculations suggest that multiple dπ(Re)→π*(phen) metal‐to‐ligand charge transfers (MLCTs) exist for each complex, two of which significantly absorb at about 340 and 385 nm, and one that emits at approximately 540 nm. In the complexes containing more‐conjugated HT ligands, non‐emissive intraligand transitions (IL(HT)) exist with energies between the ground and MLCT excited states. The overlap of these IL(HT) transitions and the absorbing MLCT of lowest energy deactivates emission resulting from about 385 nm excitation, and lowers the quantum yield and excited‐state lifetimes of these complexes. Cyclic voltammetry experiments indicate that throughout the series investigated, the highest occupied molecular orbital (HOMO) of each complex is centred on the HT ligand, while the occupied molecular orbitals localised on the rhenium are lower in energy.
Mechanism of the Catalytic Activity of Nucleophiles in the Stepwise Hydrolysis and Condensation Reactions of Tetramethoxysilane
Authors: Ignatyev Igor S. , Montejo Manuel , López González Juan Jesús
Published: March 2009

Active ingredients: A model for the simplest hydrolysis reaction is applied to all stages of stepwise hydrolysis and condensation taking place during a sol–gel process. The picture shows the molecular structures of the transition states of the ammonia‐ (left) and OH−‐promoted (right) condensation reactions of two Si(OH)4 molecules, including an additional water molecule.

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The previously proposed model of the catalytic activity of nucleophiles in the hydrolysis reaction of tetramethoxysilane is expanded to the subsequent stages of hydrolysis, that is, the stepwise hydrolysis of (MeO)4−x(OH)xSi (x=1–3) molecules, and to the condensation reaction of completely hydrolysed species. The estimate of the reaction barrier heights by using the B3LYP and MP2 methods with correlation‐consistent double‐zeta basis sets allows us to predict the catalytic activity of bases for the different steps of hydrolysis and for condensation reactions. In general, the catalytic activity of bases decreases with the number of hydrolysed groups, vanishing in the case of ammonia at x=2 and remaining in the case of the hydroxyl anion up to x=3. In addition, the value of the catalytic activity of NH3 and OH− is of the same order of magnitude for hydrolysis reactions, while the effect of the OH− anion substantially exceeds that of NH3 for condensation reactions.
Hydrogenation of CO2 to Formic Acid Promoted by a Diamine‐Functionalized Ionic Liquid
Authors: Zhang Zhaofu , Hu Suqin , Song Jinliang , Li Wenjing , Yang Guanying , Han Buxing
Published: March 2009

Amines to an end: The basic diamine‐functionalized ionic liquid 1,3‐di(N,N‐dimethylaminoethyl)‐2‐methylimidazolium trifluoromethanesulfonate was prepared and used in the hydrogenation of CO2 to formic acid. One mole of the ionic liquid coordinates two moles of formic acid to promote the reaction. Both the ionic liquid and catalyst can be reused directly after their separation from the formic acid produced.

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The pro‐Th2 cytokine IL‐33 directly interacts with invariant NKT and NK cells to induce IFN‐γ production
Authors: Bourgeois Elvire , Van Linh Pham , Samson Michel , Diem Séverine , Barra Anne , Roga Stéphane , Gombert Jean‐Marc , Schneider Elke , Dy Michel , Gourdy Pierre , Girard Jean‐Philippe , Herbelin André
Published: March 2009

IL‐33 has recently been identified as a cytokine endowed with pro‐Th2 functions, raising the question of its effect on invariant natural killer T cell (iNKT), which are potent IL‐4 producers. Here, we report a two‐fold increase of iNKT‐cell counts in spleen and liver after a 7‐day treatment of mice with IL‐33, which results from a direct effect, given that purified iNKT cells express the T1/ST2 receptor constitutively and respond to IL‐33 by in vitro expansion and functional activation. Conversely to the expected pro‐Th2 effect, IL‐33 induced a preferential increase in IFN‐γ rather than IL‐4 production upon TCR engagement that depended on endogenous IL‐12. Moreover, in combination with the pro‐inflammatory cytokine IL‐12, IL‐33 enhanced IFN‐γ production by both iNKT and NK cells. Taken together these data support the conclusion that IL‐33 can contribute as a co‐stimulatory factor to innate cellular immune responses.
Human CD4+ invariant NKT cells are involved in antibacterial immunity against Brucella suis through CD1d‐dependent but CD4‐independent mechanisms
Authors: Bessoles Stéphanie , Dudal Sherri , Besra Gurdyal S. , Sanchez Françoise , Lafont Virginie
Published: March 2009

Human invariant NKT (iNKT) cells are a unique subset of T cells, which recognize glycolipids presented by the CD1d. Among the iNKT cells, several functionally distinct subsets have been characterized according to CD4 and/or CD8 co‐receptor expression. The current study is focussed on the CD4+ iNKT cell subset and its role in an anti‐infectious response. We have examined the role of CD4+ iNKT cells on the intracellular Brucella suis growth. Our results indicate that CD4+ iNKT cells impair the intramacrophagic growth of Brucella. This inhibition is due to a combination of soluble and contact‐dependent mechanisms: IFN‐γ is weakly involved while cytotoxic activities such as the induction of the Fas pathway and the release of lytic granules are major mechanisms. The impairment of Brucella growth by CD4+ iNKT cells requires an interaction with CD1d on macrophage surface. Also, we have shown that although CD4 regulates several biological responses of CD4+ iNKT cells, it is not involved in their antibacterial activity. Here, we have shown for the first time that the CD4+ iNKT cell population has antibacterial activity and thus, participates directly in the elimination of bacteria and/or in the control of bacterial growth by killing infected cells.
Towards the Synthesis of 3‐Silapiperidines
Authors: Blaszykowski Christophe , Brancour Célia , Dhimane Anne‐Lise , Fensterbank Louis , Malacria Max
Published: March 2009

A straightforward and unprecedented method towards the synthesis of 3‐silapiperidines is described. The key step involves a formal double nucleophilic substitution reaction between the (bromomethyl)dimethylsilyl chloride and a N,C‐sp2‐1,4‐dianionic species generated from N‐monoprotected allylamines. Subsequent functionalizations are also presented.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Redox‐Controlled Dihydroazulene‐Vinylheptafulvene Photoswitch Incorporating Tetrathiafulvalene
Authors: Petersen Michael Åxman , Andersson Asbjørn Sune , Kilså Kristine , Nielsen Mogens Brøndsted
Published: March 2009

A derivative of dihydroazulene (DHA) incorporating the redox‐active unit tetrathiafulvalene (TTF) was prepared and investigated for its ability to undergo light‐induced conversion to the vinylheptafulvene (VHF) isomer. The absorption properties of the oxidized species were investigated by spectroelectrochemistry. Photoswitching was investigated as a function of the redox‐state of the TTF unit, i.e., as neutral or as radical cation, and it was found that photoswitching occurred more than twice as efficiently for the neutral species as for the radical cation species, while the thermal back reaction was unaffected. In addition, we have found that the TTF–DHA conjugate is readily converted to an azulene–TTF donor–acceptor conjugate upon treatment with strong base.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Water: A Suitable Medium for the Petasis Borono‐Mannich Reaction
Authors: Candeias Nuno R. , Veiros Luís F. , Afonso Carlos A. M. , Gois Pedro M. P.
Published: March 2009

Water was used as the solvent in the Petasis borono‐Mannich reaction. With the use of salicylaldehyde, secondary amines and boronic acids, several alkylaminophenols were obtained in considerably high yields in water. By using the same methodology, 2H‐chromenes were prepared with the use of vinyl boronic acids. The reaction mechanism was studied by DFT calculations, and the results obtained corroborate the solvent effect experimentally observed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Managing evaluation for program improvement at the Wilder Foundation
Authors: Mattessich Paul W. , Mueller Daniel P. , Holm‐Hansen Cheryl A.
Published: March 2009

The authors tell about their heterogeneous 91 person research and evaluation unit at an operating foundation in St. Paul, Minnesota. They focus on evaluation for program improvement, one of several purposes of studies they work on. The three authors write from their different manager positions within the unit. Included are the context of the organization, strategic principles of their work and how it fits into a program improvement model. Mattessich writes as the executive director and details his day‐to‐day evaluation work. Mueller writes as the associate director, who oversees most of the unit's evaluation work, while Holm‐Hansen writes as a consulting scientist who leads a core research team of four to six. © Wiley Periodicals, Inc.
Priority setting in practice: what is the best way to compare costs and benefits?
Authors: Wilson Edward C. F. , Peacock Stuart J. , Ruta Danny
Published: March 2009

Prioritising candidates for health‐care expenditure using cost per Quality‐Adjusted Life Year (QALY) is a helpful but insufficient means of ranking alternative uses for scarce health‐care funds at the local level. This is because QALYs do not by themselves capture all criteria decision makers need to take into account. Other criteria such as reducing inequalities, meeting national and local priorities and public acceptability also feature in the decision maker's utility function.

Programme budgeting and marginal analysis (PBMA) is an established framework for systematic priority setting in which a ‘weighted benefit score’ for each option is calculated based on all relevant decision‐making criteria. Ranking options as a ratio of cost to benefit is desirable and necessary to ensure efficiency.

In this paper we review a number of approaches to scoring costs and benefits of options in a PBMA context. Several approaches rank by benefit score alone, rather than efficiency (cost per unit of benefit). Of those that do rank by efficiency, we discuss the benefits and drawbacks. The optimal approach is far from clear, with each technique having its own strengths and weaknesses. A deliberative approach using summaries of costs and benefits of options as a basis for discussion may be preferable. Copyright © 2008 John Wiley & Sons, Ltd.
Ab initio theory for treating local electron excitations in molecules and its performance for computing optical properties
Authors: Miura Masanori , Aoki Yuriko
Published: March 2009

In this article, as a first step to develop an efficient approximation for predicting the molecular electronic excited state properties at ab initio level, we propose local excitation approximation (LEA). In the LEA scheme, the only local electron excitations within selected substructure (Chromophore) are treated to calculate the targeted excited state wavefunctions, whereas the other electron excitations (local electron excitations in other substructure and charge‐transfer excitations between different regions) are simply discarded. This concept is realized by using the localized molecular orbitals (LMO) localizing on the chromophore substructure. If the targeted transitions show the strong local character and the adequate substructure is selected as chromophore region, the LEA scheme can provide excited state properties without large loss of accuracy. The fatal slowdown of convergence speed of Davidson's iterative diagonalization due to the use of LMO can be avoided by additional transformation of LMOs. To assess the accuracy and efficiency of the LEA scheme, we performed test calculations using various compounds at configuration interaction single (CIS) and time‐dependent Hartree‐Fock (TDHF) level of theory. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009
Dissociative photoionization of isoprene: experiments and calculations
Authors: Liu Xianyun , Zhang Weijun , Wang Zhenya , Huang Mingqiang , Yang Xibin , Tao Ling , Sun Yue , Xu Yuntao , Shan Xiaobin , Liu Fuyi , Sheng Liusi
Published: March 2009

Vacuum ultraviolet (VUV) dissociative photoionization of isoprene in the energy region 8.5–18 eV was investigated with photoionization mass spectroscopy (PIMS) using synchrotron radiation (SR). The ionization energy (IE) of isoprene as well as the appearance energies (AEs) of its fragment ions C5H7+, C5H5+, C4H5+, C3H6+, C3H5+, C3H4+, C3H3+ and C2H3+ were determined with photoionization efficiency (PIE) curves. The dissociation energies of some possible dissociation channels to produce those fragment ions were also determined experimentally. The total energies of C5H8 and its main fragments were calculated using the Gaussian 03 program and the Gaussian‐2 method. The IE of C5H8, the AEs for its fragment ions, and the dissociation energies to produce them were predicted using the high‐accuracy energy model. According to our results, the experimental dissociation energies were in reasonable agreement with the calculated values of the proposed photodissociation channels of C5H8. Copyright © 2009 John Wiley & Sons, Ltd.
The analysis of industrial synthetic polymers by electrospray droplet impact/secondary ion mass spectrometry
Authors: Asakawa Daiki , Chen Lee Chuin , Hiraoka Kenzo
Published: March 2009

Electrospray droplet impact (EDI)/secondary ion mass spectrometry (SIMS) is a new desorption/ionization technique for mass spectrometry in which highly charged water clusters produced from the atmospheric‐pressure electrospray are accelerated in vacuum by several kV and impact the sample deposited on the metal substrate. In this study, several industrial synthetic polymers, e.g. polystyrene (PS) and polyethylene glycol (PEG) were analyzed by EDI/SIMS mass spectrometry. For higher molecular weight analytes, e.g. PS4000 and PEG4600, EDI/SIMS mass spectra could be obtained when cationization salts are added. For the polymers of lower molecular weights, e.g. PEG300 and PEG600, they could be readily detected as protonated ions without the addition of cationization agents. Anionized PS was also observed in the negative ion mode of operation when acetic acid was added to the charged droplet. Compared to matrix‐assisted laser desorption/ionization (MALDI), ion signal distribution with lower background signals could be obtained particularly for the low‐molecular weight polymers. Copyright © 2009 John Wiley & Sons, Ltd.
Radial distribution of the contributions to band broadening of a silica‐based semi‐preparative monolithic column
Authors: Abia Jude A. , Mriziq Khaled S. , Guiochon Georges A.
Published: March 2009

Using an on‐column local electrochemical microdetector operated in the amperometric mode, band elution profiles were recorded at different radial locations at the exit of a 10 mm id, 100 mm long silica‐based monolithic column. HETP plots were then acquired at each of these locations, and all these results were fitted to the Knox equation. This provided a spatial distribution of the values of the eddy diffusion (A), the molecular diffusion (B), and the resistance to the kinetics of mass transfer (C) terms. Results obtained indicate that the wall region yields higher A values and smaller C values than the central core region. Significant radial fluctuations of these contributions to band broadening occur throughout the exit column cross‐section. This phenomenon is due to the structural radial heterogeneity of the column.
Solid phase extraction of polyhalogenated pollutants from freshwater using chemically modified multi‐walled carbon nanotubes and their determination by gas chromatography
Authors: Abdel Salam Mohamed , Burk Robert
Published: March 2009

This paper describes the application of pristine and chemically modified multi‐walled carbon nanotubes (MWCNTs) as packing materials for the preconcentration and determination of various polyhalogenated organic pollutants, pentachlorophenol, 2,4,5‐trichlorophenol, 3,3′,4,4′‐tetrachlorobiphenyl, and 2,2′,5,5′‐tetrabromobiphenyl from real water samples based on solid‐phase extraction. MWCNTs were chemically modified by octadecyl amine and polyethylene glycol, separately, and the resulting nano materials were used as packing materials for solid phase extraction. Method development, applicability, and suitability of the above mentioned adsorbents for the solid phase extraction were studied. Method development showed great reproducibility and sensitivity, and low limits of detection within a considerable linear range. The regeneration and reusability of the SPE cartridges were studied using Rideau River (Ottawa, Canada) surface water samples and the results showed that cartridges could be used for three cycles of adsorption/desorption with no loss of efficiency. In general, the results suggested that modification of MWCNTs affords a novel class of adsorbents, which could be used for the SPE of various analytes from aqueous solutions with great efficiency, recovery, reproducibility, sensitivity, and precision, within a wide range of analyte concentrations.
Influence of temperature on mass transfer in an incomplete trapping supported liquid membrane extraction of triazole fungicides
Authors: Chimuka Luke , Michel Monika , Cukrowska Ewa , Buszewski Boguslaw
Published: March 2009

The influence of temperature in a supported liquid membrane (SLM) extraction of triazole fungicides was investigated. The mass transfer parameters such as diffusion coefficient, flux and apparent viscosity were determined at temperatures ranging from 5 to 40°C. Increase in temperature led to an increase in diffusion coefficient and flux with a flowing acceptor solution. The apparent viscosity also decreased with an increase in temperature. However, the increase in mass transfer parameters did not result in an overall increase in extraction efficiency with a stagnant or circulation acceptor phase. Stripping of the analytes from the membrane into the acceptor phase as well as the configuration of the extraction unit could have limited the influence of temperature on mass transfer. The partition coefficient of analytes from the acceptor solution to the membrane, KA, was found to be much higher than that from the donor solution to the membrane KD, thus triazole compounds preferred to remain in the membrane even with an increased extraction temperature.
Epoxycarotenoids esters analysis in intact orange juices using two‐dimensional comprehensive liquid chromatography
Authors: Dugo Paola , Giuffrida Daniele , Herrero Miguel , Donato Paola , Mondello Luigi
Published: March 2009

In this work, the native carotenoid pattern of different orange juices was studied by LC×LC‐DAD/APCI‐IT‐TOF‐MS for the first time. Special attention was given to the epoxycarotenoids components. It has been already proposed that the relative proportions and composition of these epoxycarotenoids can be used to estimate the age and freshness of an orange juice. Re‐arrangements from 5,6‐ to 5,8‐epoxides can occur with time, partially due to the natural acidity of the juices. Thus, the study of these carotenoids in their intact form, that is, esterified with fatty acids, is of great interest. Besides, other free carotenoid and carotenoids esters were identified in seven different monovarietal orange juices and a commercial orange juice. Moreover, the higher separation power of the present LC×LC approach allowed a clearer identification of the compounds contained in the sample compared to the more commonly used approach which uses C30 stationary phases in conventional LC, thanks to the attainment of clearer MS spectra due to the higher resolution and separation degree obtained in LC×LC. This method could also be used to establish authenticity markers among orange varieties that could be potentially used to prevent or detect adulterations or to establish ripeness indexes.
Topology optimization of plane frames in case of random external loadings
Authors: Zier Simone
Published: March 2009

Using the first collapse–theorem, the necessary and sufficient survival conditions of an elasto–plastic structure consist of the yield condition and the equilibrium condition. In practical applications several random model parameters have to be taken into account. This leads to a stochastic optimization problem which cannot be solved using the traditional methods. Instead of that, appropriate (deterministic) substitute problems must be formulated. Here, the topology optimization of frames is considered, where the external load is supposed to be stochastic. The recourse problem will be formulated in general and in the standard form of stochastic linear programming (SLP). After the formulation of the stochastic optimization problem, the recourse problem with discretization and the expected value problem are introduced as representatives of substitute problems. Subsequently, numerical results using these methods are presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Research about transmission of the mechanical vibration done by machine‐tools on the group of bones shoulder‐neck‐head
Authors: Trutą Aurica , Pop Aurora Felicia , Arghir Mariana
Published: March 2009

Different researches have shown that long–term exposure to whole–body vibration can induce different injuries like back pain, injuries of the different part of the body, disturbing the physical and intellectual activities. The resulted diseases could be occasional or could be for ever. Bearing in mind that vibration is applied on the hand or feet, the health rick can be assessed if the forces transmitted in the shoulder during vibration are known. To estimate the forces a biomechanical model has been developed in which the shoulder, neck and head are represented by rigid bodies. The bodies are connected by visco–elastic joint elements. The applied forces are resulted from experimental measurements. To assess the health risk the forces must be divised in two components, an ascendant one and a descendent one. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On rate independent models for crack propagation
Authors: Knees Dorothee , Mielke Alexander , Zanini Chiara
Published: March 2009

We model the evolution of a single crack as a rate–independent process based on the Griffith criterion. Three approaches are presented, namely a model based on global energy minimization, a model based on a local description involving the energy release rate and a refined local model which is the limit problem of regularized, viscous models. Finally we present an example which sheds light on the different predictions of the models. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Validation and Limits of Finite Inflatable Beam Elements
Authors: Haßler Marc , Schweizerhof Karl
Published: March 2009

Although nowadays inflatable tubular beams are often used in the field of civil engineering, by now there are only few publications dealing with finite deformation inflatable beam elements, see e.g. [1], [2] and [3]. All formulations of inflatable beams have several assumptions in common, as constant cross sections throughout the deformation, a constant internal gas pressure and the negligence of circumferential stresses. These assumptions have to be validated either by experiments or numerical analysis. In the current contribution beam–like structures are investigated using a finite element shell or membrane formulation and featuring a volume dependent gas loading, see e.g. [5] and [4]. In general the formulation substitutes the internal gas pressure by an energetically equivalent volume dependent loading and thus enables to check for potential gas pressure changes during the deformation process of the inflated beam as a consequence of volume changes. Further local deformations as occurring in the vicinity of supports or almost single loads can be considered. In this paper the focus will be only on the initial assumption of the beam theory that the biaxial stress state is neglected. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐conforming FEM‐BEM coupling for wave propagation phenomena
Authors: Rüberg Thomas , Schanz Martin , Beer Gernot
Published: March 2009

In this paper, a method for coupling finite and boundary element discretizations is presented which allows for non–conforming interface discretizations. This method is applicable (but not restricted ) to static and dynamic problems of acoustics and structural mechanics. The main idea is to employ discrete Dirichlet–to–Neumann maps at each time step within the framework of a Lagrange multiplier domain decomposition method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multidimensional life cycle assessment on various moulded pulp production systems
Authors: Huo Lijiang , Saito Katsuhiko
Published: March 2009

Moulded pulp has been used as an alternative to plastic in certain packaging applications, but some problems in the production system lead to higher costs including energy consumption. Industry tends to operate on the basis of experience rather than through scientific evaluation and systematic design methods. The research aims at detecting the problems in the production system by a multidimensional life cycle assessment (MLCA) with transparent analysis. The MLCA measures the performance of the moulded pulp production system with regard to technical, economic and environmental aspects and produces quantitative results (in monetary units), and finally indicates the overall efficiency of the production system using a sustainability index (SI). A life cycle impact assessment method based on endpoint modelling (LIME) is mainly adopted in the MLCA. Three existing moulded pulp production systems for industrial packaging in China were assessed in this study. The results show that the main environmental impacts of the three production systems are the atmospheric emissions and landfill waste; the drying stage in the production systems, which is dominated by consumption of resources and environmental impacts, is the key to controlling costs; steam should be the first preferred heat source in the drying process for achieving sustainability in the moulded pulp production system. The optimum for the three cases is identified by calculating the newly developed SI. The MLCA approach can be used to assist in identifying potential improvements and practical new packaging designs. Copyright © 2009 John Wiley & Sons, Ltd.
Practical application of the vanishing tetrad test for causal indicator measurement models: An example from health‐related quality of life
Authors: Bollen Kenneth A. , Lennox Richard D. , Dahly Darren L.
Published: March 2009

Researchers are often faced with the task of trying to measure abstract concepts. The most common approach is to use multiple indicators that reflect an underlying latent variable. However, this ‘effect indicator’ measurement model is not always appropriate; sometimes the indicators instead cause the construct of interest. While the notion of ‘causal indicators’ has been known for some time, it is still too often ignored. However, there are limited means to determine whether a possible indicator should be treated as a cause or an effect of the latent construct of interest. Perhaps the best empirical way is to use the vanishing tetrad test (VTT), yet this method is still often overlooked. We speculate that one reason for this is the lack of published examples of its use in practice, written for an audience without extensive statistical training. The goal of this paper was to help fill this gap in the literature—to provide a basic example of how to use the VTT. We illustrated the VTT by looking at multiple items from a health related quality of life instrument that seem more likely to cause the latent variable rather than the other way around. Copyright © 2009 John Wiley & Sons, Ltd.
Using multiple frames in health surveys
Authors: Metcalf Patricia , Scott Alastair
Published: March 2009

In this paper, we look at a unified approach to estimation in multiple frame surveys that enables the analysis to be handled with standard survey software. We investigate how the approach performs with data from the Auckland Diabetes, Heart and Health Survey, a dual frame survey looking at risk factors for cardiovascular disease with special attention to Maori and Pacific Island people and to older people. The results suggest that the use of multiple frames might be useful in other surveys where good estimates are wanted for both the whole population and particular subgroups at the same time. Copyright © 2009 John Wiley & Sons, Ltd.
Animal models of maple syrup urine disease
Authors: Skvorak K. J.
Published: March 2009

Maple syrup urine disease (MSUD) is an inherited aminoacidopathy resulting from dysfunction of the branched‐chain keto acid dehydrogenase (BCKDH) complex. This disease is currently treated primarily by dietary restriction of branched‐chain amino acids (BCAAs). However, dietary compliance is often challenging. Conversely, liver transplantation significantly improves outcomes, but donor organs are scarce and there are high costs and potential risks associated with this invasive procedure. Therefore, improved treatment options for MSUD are needed. Development of novel treatments could be facilitated by animal models that accurately mimic the human disease. Animal models provide a useful system in which to explore disease mechanisms and new preclinical therapies. Here we review MSUD and currently available animal models and their corresponding relevance to the human disorder. Using animal models to gain a more complete understanding of the pathophysiology behind the human disease may lead to new or improved therapies to treat or potentially cure the disorder.
Conjugated Linoleic Acid Decreases MCF‐7 Human Breast Cancer Cell Growth and Insulin‐Like Growth Factor‐1 Receptor Levels
Authors: Amarù Danielle L. , Field Catherine J.
Published: March 2009

In vitro work suggests that conjugated linoleic acid (CLA) isomers (c9,t11 and t10,c12) are cytotoxic to human breast cancer cells, however the mechanism remains unknown. Using human MCF‐7 breast cancer cells, we examined the effects of c9,t11 and t10,c12 CLA compared to oleic acid (OA), linoleic acid (LA), or untreated cells on cell membrane phospholipid composition, cell survival, and the insulin‐like growth factor‐I (IGF‐I) and the downstream insulin receptor substrate‐1 (IRS‐1). Both CLA isomers were incorporated into membrane phospholipids (p < 0.05). Compared to untreated cells, c9,t11 or t10,c12 CLA significantly reduced the metabolic activity of IGF‐I stimulated MCF‐7 cells, increased lactate dehydrogenase (LDH) release, and decreased cellular concentrations of the IGF‐I receptor (IGF‐IR) and insulin receptor substrate‐1 (p < 0.05). Incubation with t10,c12 CLA also reduced the levels of phosphorylated IGF‐1R. The effects on all of these measures were greater (p < 0.05) for t10,c12 CLA compared to c9,t11 CLA. There were few differences between LA‐treated and c9,t11 CLA‐treated cells, whereas cellular metabolic activity, LDH release, and IGF‐IR concentrations differed between t10,c12 CLA‐treated and LA‐treated cells (p < 0.05). OA stimulated growth compared to the untreated condition (p < 0.05). In summary, this study demonstrated that the t10,c12 CLA isomer inhibits growth of MCF‐7 cells and suggested that this may be mediated through incorporation into cellular phospholipids and interference with the function of IGF‐I and related signaling proteins.
New 17‐Methyl‐13‐Octadecenoic and 3,16‐Docosadienoic Acids from the Sponge Polymastia penicillus
Authors: Denis Claire , Wielgosz‐Collin Gaëtane , Bretéché Anne , Ruiz Nicolas , Rabesaotra Vony , Boury‐Esnault Nicole , Kornprobst Jean‐Michel , Barnathan Gilles
Published: March 2009

The phospholipid fatty acid composition of the North‐East Atlantic sponge Polymastiapenicillus (South Brittany, France) was investigated. Sixty fatty acids (FA) were identified as methyl esters (FAME) and N‐acyl pyrrolidides (NAP) by gas chromatography–mass spectrometry (GC/MS), including eight Δ5,9 unsaturated FA and three long‐chain 2‐hydroxylated FA. The major phospholipid FA were palmitic (14.3% of the total FA mixture), vaccenic (12.7%), 15(Z)‐docosenoic (13.4%) and 5(Z),9(Z)‐hexacosadienoic (13.3%) acids. In addition to the iso‐ and anteiso‐branched saturated FA, several unusual short‐chain branched saturated FA were identified. In addition to the known Δ5,9 FA, and interestingly regarding their identification by GC–MS as N‐acyl pyrrolidides, was the co‐occurrence of unusual FA possessing a Δ3, Δ4 and Δ5 double bond such as iso‐4‐pentadecenoic, iso‐5‐heptadecenoic, anteiso‐5‐heptadecenoic and two new compounds, not hitherto found in nature, namely 17‐methyl‐13‐octadecenoic (0.8%) and 3,16‐docosadienoic (1.1%) acids.
Morphological and molecular studies on life cycle stages of Diphtherostomum brusinae (Digenea: Zoogonidae) from northern Portugal
Authors: Pina S. , Tajdari J. , Russell-Pinto F. , Rodrigues P.
Published: March 2009

Diphtherostomum brusinae was first recorded by the present study in the north of Portugal. Sporocysts, containing cercariae and encysted metacercariae, were observed in the gonads and digestive gland of the gastropod Nassarius reticulatus. Metacercariae were also found infecting the foot, mantle border and gills of the cockle Cerastoderma edule. The adult form was lodged in the rectum of the definitive host Diplodus sargus. The morphology of the three parasitic stages was studied by light (LM) and scanning electron microscopy (SEM). Despite the close similarity between cercaria and metacercaria, SEM data provided information that allowed their differentiation, namely the presence of a dense crown of microvilli around the oral cavity of the cercariae, which was absent in the metacercariae. In addition, the metacercariae presented a specific pre-acetabular rectangular band with conspicuous triangular spines. The adult showed characteristics of D. brusinae species, in particular the presence of acetabular lips, compact vitellaria and large elliptical eggs. Sequenced ITS1 data clearly demonstrated that the cercariae and metacercarial cysts from N. reticulatus, the cysts from C. edule and the adult isolated from D. sargus were life cycle stages that belonged to the same species, i.e. D. brusinae. Two transmission strategies in the life cycle of this species were observed: (1) cercariae encyst within the sporocysts of N. reticulatus and await ingestion by the definitive host; and (2) N. reticulatus naturally emits cercariae; they encyst in C. edule or the environment and are ingested by the definitive host.
Open Clusters as tracers of the Galactic disk: the Bologna Open Clusters Chemical Evolution project
Authors: Bragaglia Angela , Carretta Eugenio , Gratton Raffaele , Tosi Monica
Published: March 2009

We present an update of the Bologna Open Clusters Chemical Evolution project (BOCCE, in short). We are conducting a photometric and spectroscopic survey of Open Clusters, to be used as tracers of the Galactic disk properties and evolution. We obtain the clusters parameters (age, distance, metallicity, and detailed abundances) in a precise and homogeneous way. We have collected data for about 40 Open Clusters and have fully analyzed the photometric data for about one half and the spectra for one quarter of them. We present here results based on these works and indicate what will come next.
Spiral Arm Tangencies in the Milky Way
Authors: Benjamin Robert A.
Published: March 2009

The historical directions of spiral arm tangencies in the Milky Way are presented and compared to results of mid-infrared star counts using the Spitzer Space Telescope. While the Scutum and Centaurus tangency directions show a 20-30% excess of star counts, all other expected tangency directions show no similar increases. These two tangencies are probably associated with a density wave arm that comes off the near side of the bar of the Galaxy while the other arms whose tangencies are not detected may be compression in the gas, but not in the old stellar disk.
The Galaxy and its stellar halo - insights from a hybrid cosmological approach
Authors: De Lucia Gabriella , Helmi Amina
Published: March 2009

We use a series of high-resolution N-body simulations of a ‘Milky-Way’ halo, coupled to semi-analytic techniques, to study the formation of our own Galaxy and of its stellar halo. Our model Milky Way galaxy is a relatively young system whose physical properties are in quite good agreement with observational determinations. In our model, the stellar halo is mainly formed from a few massive satellites accreted early on during the galaxy's lifetime. The stars in the halo do not exhibit any metallicity gradient, but higher metallicity stars are more centrally concentrated than stars with lower abundances. This is due to the fact that the most massive satellites contributing to the stellar halo are also more metal rich, and dynamical friction drags them closer to the inner regions of the host halo.
Development and Initial Validation of an Obesity‐specific Quality‐of‐life Measure for Children: Sizing Me Up
Authors: Zeller Meg H. , Modi Avani C.
Published: March 2009

The present study describes the development and initial validation of a new obesity‐specific, self‐report measure of health‐related quality of life (HRQOL) for children aged 5–13 years. Participants included 141 obese children (mean age = 9.2 years, 67% female, 55% black, mean zBMI = 2.52) and their primary caregivers. Children completed Sizing Me Up (obesity‐specific HRQOL) and the PedsQL (generic HRQOL). Item content for Sizing Me Up was based on the published child obesity and HRQOL literatures and expert opinion. Items use phrasing to orient children to respond to questions in context of his/her size (e.g., “were teased by other kids because of your size”). Caregivers completed Sizing Them Up, a parallel parent‐proxy, obesity‐specific HRQOL measure. Initial psychometric evaluation of Sizing Me Up was completed by conducting a factor analysis and determining internal consistency, test–retest reliability, and convergent and construct validity. Sizing Me Up is a 22‐item measure with five scales (i.e., Emotional Functioning, Physical Functioning, Social Avoidance, Positive Social Attributes, and Teasing/Marginalization) that account for 57% of the variance and a total HRQOL score. Internal consistency coefficients range from 0.68 to 0.85. Test–retest reliabilities range from 0.53 to 0.78. Good convergent validity was demonstrated with the PedsQL (rs = 0.35–0.65) and the parent‐proxy Sizing Them Up (rs = 0.22–0.44). Sizing Me Up represents the first obesity‐specific HRQOL measure developed specifically for younger school‐aged children (aged 5–13 years) with preliminary evidence of strong psychometric properties that likely has both clinical and research utility in a variety of settings.
Accelerated coarsening of Ag adatom islands on Ag(111) due to trace amounts of S: Mass-transport mediated by Ag–S complexes
Authors: Shen Mingmin , Liu Da-Jiang , Jenks C. J. , Thiel P. A. , Evans J. W.
Published: March 2009

Scanning tunneling microscopy studies reveal that trace amounts of adsorbed S below a critical coverage on the order of 10mML have little effect on the coarsening and decay of monolayer Ag adatom islands on Ag(111) at 300K. In contrast, above this critical coverage, decay is greatly accelerated. This critical value appears to be determined by whether all S can be accommodated at step edges. Accelerated coarsening derives from the feature that the excess S (above that incorporated at steps) produces significant populations on the terraces of metal-sulfur complexes, which are stabilized by strong Ag–S bonding. These include AgS2, Ag2S2, Ag2S3, and Ag3S3. Such complexes are sufficiently populous and mobile that they can potentially lead to greatly enhanced metal mass transport across the surface. This picture is supported by density functional theory analysis of the relevant energetics, as well as by reaction-diffusion equation modeling to assess the mechanism and degree of enhanced coarsening.
High-quality MeV protons from laser interaction with umbrellalike cavity target
Authors: Ma Y. Y. , Sheng Z. M. , Gu Y. Q. , Yu M. Y. , Yin Y. , Shao F. Q. , Yu T. P. , Chang W. W.
Published: March 2009

A scheme for producing high-intensity collimated MeV protons from laser interaction with an umbrellalike (cone cavity with an axial filament stemming from the apex) target back side is investigated by two- and three-dimensional particle-in-cell simulations. The process is based on target-normal sheath acceleration. The characteristics of the proton beam are analyzed and compared to that from the recently proposed cone-shaped back side target. It is found that instead of diverging after first focusing, as in the cone-shaped target, the protons produced from the umbrellalike target are well collimated. The large transverse sheath electric field at TV/m level and the self-generated quasistatic magnetic field at hundreds of megagauss level around the filament play important roles in the collimation of the protons.
Effect of germanium substrate loss and nitrogen on dopant diffusion in germanium
Authors: Chroneos A.
Published: March 2009

Recent experimental studies demonstrate a significant germanium (Ge) substrate loss and consequently dopant loss even during low temperature annealing. Additionally, for phosphorous (P) implanted Ge the capping layer material affects P diffusion. Silicon nitride (Si3N4) capping is more efficient compared to silicon dioxide (SiO2) capping, but an accumulation of P is observed at the Ge/Si3N4 interface. In the present study, the recent experimental evidence is evaluated and with the use of electronic structure simulations the formation of relevant defects is investigated. It is predicted that the formation of clusters containing nitrogen (N) and vacancies (V) can be related to the observed accumulation of P atoms near the Ge/Si3N4 interface.
Al-centered icosahedral ordering in Cu46Zr46Al8 bulk metallic glass
Authors: Fang H. Z. , Hui X. , Chen G. L. , Liu Z. K.
Published: March 2009

Icosahedral short-range order, of which Al atoms are caged in the center of icosahedra with Cu and Zr atoms being the vertices, has been evidenced in the Cu46Zr46Al8 glassy structure by ab initio molecular dynamics simulation. These Al-centered clusters distribute irregularly in the three-dimensional space and form a “backbone” structure of the Cu46Zr46Al8 glass alloy. It is suggested that this kind of local structural feature is attributed to the requirement of efficient dense packing and the chemical affinity between Zr–Zr, Zr–Al, and Cu–Zr atoms. Our calculated results are found to be in good agreement with the experimental data.
High mobility holes in a strained Ge quantum well grown on a thin and relaxed Si0.4Ge0.6/LT-Si0.4Ge0.6/Si(001) virtual substrate
Authors: Myronov M. , Leadley D. R. , Shiraki Y.
Published: March 2009

Epitaxial growth of a compressively strained Ge quantum well (QW) on an ultrathin, 345 nm thick, Si0.4Ge0.6/LT-Si0.4Ge0.6/Si(001) virtual substrate (VS) has been demonstrated. The VS, grown with a low temperature Si0.4Ge0.6 seed layer on a Si(001) substrate, is found to be fully relaxed and the Ge QW is fully strained. The temperature dependence of Hall mobility and carrier density clearly indicates a two-dimensional hole gas in the Ge QW. At room temperature, which is more relevant for electronic devices applications, the samples show a very high Hall mobility of 1235 cm2 V−1 s−1 at a carrier density of 2.36×1012 cm−2.