bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Thermal Reactivity of β‐(1,2‐Allenyl)butenolides and 2‐Allyl‐3‐allenylcyclohex‐2‐enones
Authors: Gu Zhenhua , Ma Shengming
Published: January 2008

A series of thermal pericyclic reactions of β‐allenylfuranones have been studied. It was observed that β‐allenylfuranones would undergo 1,5‐hydrogen shift to afford a new type of trienes upon heating. Due to their high reactivity, these trienes would undergo subsequent pericyclic reactions based on the nature of the substituent group R: When R is an alkyl group, the intermediate 4 a or 4 b would undergo a further 1,7‐hydrogen shift to afford a more stable conjugated triene 3; with R being phenyl or cyclopropyl group, the 1,7‐hydrogen shift was inhibited and the 4‐type conjugated triene would form a six‐membered ring 5 via 6π‐electrocyclization. Interestingly, introducing another CC double bond into the triene intermediate (R = CHCH2), the 18‐type intermediate would undergo 8π‐electrocyclization reaction to form an eight‐membered ring. Such a transformation was also observed with 2‐allyl‐3‐allenylcyclohex‐2‐enones. The deuterium‐labeling mechanistic studies show that the alkyl groups at the allenyl moiety of 1 participated in the isomerization process via 1,7‐hydrogen shifts between 18 A, 20 A, and 29 A.
Structurally Characterized Coinage‐Metal–Ethylene Complexes (Eur. J. Inorg. Chem. 4/2008)
Authors: Dias H. V. Rasika , Wu Jiang
Published: January 2008

the cover picture shows the formation of coinage metal (copper, silver, gold) complexes of ethylene supported by scorpionate ligands on an X‐ray diffraction background (because the article focuses on the structurally characterized molecules). Thermally stable molecules containing bonds between coinage metal atoms and ethylene are still rare but have grown in number significantly over the last few years. Tris(pyrazolyl)borate (commonly known as scorpionate) ligands have played a major role in this chemistry. Indeed, they have served as the supporting ligands in the isolation of the first ethylene adduct of all three coinage metal ions. Most of the resulting complexes feature κ3‐bonded scorpionate ligands, while a few others show rare κ2‐coordination (as depicted here, a gold atom held by a scorpion with the scorpion's tail up). Details are presented in the Microreview by H. V. R. Dias and J. Wu on p. 509 ff. H. V. R. D. gratefully acknowledges the Robert A. Welch Foundation (grant Y‐1289) for providing financial support for his research.
Salinograph trends as indicators of the recession characteristics of stream components
Authors: Werner A. D. , Wood M. , Simmons C. T. , Lockington D. A.
Published: January 2008

Compared to hydrograph recession analysis, which is widely applied in engineering hydrology, the quantitative assessment of stream salinity with time (i.e. the salinograph) has received significantly less attention. In particular, while in many previous hydrological studies an inverse relationship between hydrograph and salinograph responses is apparent, the concept of salinity accession (the inversely related salinity counterpart to hydrograph recession) has not been introduced nor quantitatively evaluated in previous literature. In this study, we conduct a mathematical analysis of salinograph accession, and determine new quantitative relationships between salinity accession and hydrograph recession parameters. An equation is formulated that reproduces the general trend in salinity accession. A salinity accession parameter kc is then introduced and is shown to be the ratio of direct runoff to total stream flow recession parameters: kr/k. The groundwater recession parameter kg was estimated using a simple and rapid method that uses both salinograph and hydrograph data. Salinity accession type‐curves illustrate that under certain conditions, the relative steepness of individual salinographs is dependent upon the ratio of groundwater salinity to direct runoff salinity: Cg/Cr. The salinity accession algorithms are applied to two contrasting field settings: Scott Creek, South Australia and Sandy Creek, northern Queensland, Australia. It was found that kg > k during periods of obvious stream flow recession, for the events analysed. Salinograph accession behaviour was fairly similar for both sites, despite contrasting environments. Using assumed end‐member salinities for groundwater and direct runoff based upon field observations, the behaviour of kc from the Scott Creek site was approximately reproduced by varying the initial groundwater to runoff flow ratio: Qg0/Qr0, within reasonable parameter ranges. The use of salinograph information when used in addition to standard hydrograph analyses provided useful information on recession characteristics of stream components. Copyright © 2008 John Wiley & Sons, Ltd.
Adeno‐associated virus vector‐mediated systemic interleukin‐10 expression ameliorates hypertensive organ damage in Dahl salt‐sensitive rats
Authors: Nonaka‐Sarukawa Mutsuko , Okada Takashi , Ito Takayuki , Yamamoto Keiji , Yoshioka Toru , Nomoto Tatsuya , Hojo Yukihiro , Shimpo Masahisa , Urabe Masashi , Mizukami Hiroaki , Kume Akihiro , Ikeda Uichi , Shimada Kazuyuki , Ozawa Keiya
Published: January 2008

Background

Inflammation plays an important role in the pathogenesis of hypertension and hypertensive organ damage. Interleukin (IL)‐10, a pleiotropic anti‐inflammatory cytokine, exerts vasculoprotective effects in many animal models. In the present study, we examined the preventive effects of adeno‐associated virus (AAV) vector‐mediated sustained IL‐10 expression against hypertensive heart disease and renal dysfunction in Dahl salt‐sensitive rats.

Methods

We injected the rats intramuscularly with an AAV type 1‐based vector encoding rat IL‐10 or enhanced green fluorescent protein (EGFP) at 5 weeks of age; subsequently, the rats were fed a high‐sodium diet from 6 weeks of age.

Results

Sustained IL‐10 expression significantly improved survival rate of Dahl salt‐sensitive rats compared with EGFP expression (62.5% versus 0%, p < 0.001); it also caused 26.0% reduction in systolic blood pressure at 15 weeks (p < 0.0001). Echocardiography exhibited a 22.0% reduction in hypertrophy (p < 0.0001) and a 26.3% improvement in fractional shortening (p < 0.0001) of the rat left ventricle in the IL‐10 group compared to the EGFP group. IL‐10 expression also caused a 21.7% decrease in the heart weight/body weight index and cardiac atrial natriuretic peptide levels. Histopathological studies revealed that IL‐10 decreased inflammatory cell infiltration, fibrosis, and transforming growth factor‐β1 levels in the failing heart. Furthermore, IL‐10 expression significantly reduced urine protein excretion with increased glomerular filtration rates.

Conclusions

This is the first study to demonstrate that the anti‐inflammatory cytokine IL‐10 has a significant anti‐hypertensive effect. AAV vector‐mediated IL‐10 expression potentially prevents the progression of refractory hypertension and hypertensive organ damage in humans. Copyright © 2008 John Wiley & Sons, Ltd.
Maximizing the number of independent subsets over trees with bounded degree
Authors: Heuberger Clemens , Wagner Stephan G
Published: January 2008

The number of independent vertex subsets is a graph parameter that is, apart from its purely mathematical importance, of interest in mathematical chemistry. In particular, the problem of maximizing or minimizing the number of independent vertex subsets within a given class of graphs has already been investigated by many authors. In view of the applications of this graph parameter, trees of restricted degree are of particular interest. In the current article, we give a characterization of the trees with given maximum degree which maximize the number of independent subsets, and show that these trees also minimize the number of independent edge subsets. The structure of these trees is quite interesting and unexpected: it can be described by means of a novel digital system—in the case of maximum degree 3, we obtain a binary system using the digits 1 and 4. The proof mainly depends on an exchange lemma for branches of a tree. © 2008 Wiley Periodicals, Inc. J Graph Theory 58: 49–68, 2008
Excess thermodynamic properties in liquid binary mixtures
Authors: Aliotta F. , Saija F. , Ponterio R. C.
Published: January 2008

Excess volumes and adiabatic compressibility have been measured in several binary liquid mixtures to answer the question whether structural information can be gained through the analysis of the concentration dependence of the excess quantities. The obtained results are compared with independent indications from Raman spectroscopy, which is able to probe directly the occurrence and the nature of effective intermolecular interactions. Some doubts have arisen against the usual approach adopted for estimating the excess quantities and about the adequacy of the usual assumptions for the reference ideal behaviours. In particular, it is shown how excess compressibility can result just from statistical effects also in absence of any excess volume contribution. The leading idea is supported by the comparison of the experimental data with the results from a naive model for binary mixtures of hard spheres. The model turns out to be able to produce a very wide spectrum of structural and thermodynamic behaviours depending on the values of its parameters and on the nature (additive or non‐additive) of the hard‐sphere potential. A discussion is proposed on the re‐evaluation of excess thermodynamic data and on their ability in providing direct information on intermolecular interactions. Copyright © 2008 John Wiley & Sons, Ltd.
Texture analysis of raw and cooked tubers of short‐duration lines of cassava by multivariate and fractional conversion techniques
Authors: Sajeev Moothandassery S , Sreekumar Janardhanan , Moorthy Subramoney N , Suja Girija , Shanavas Salim
Published: January 2008

BACKGROUND:Cassava tubers are mainly consumed after boiling in water. Their cooking quality depends on the variety, maturity, growing conditions and physicochemical and starch properties. In this study the textural and gelatinisation characteristics of ten short‐duration lines of cassava were assessed. Textural changes due to cooking were modelled by fractional conversion techniques and correlated with gelatinisation and physicochemical properties by principal component analysis.

RESULTS:There was a significant variation (P< 0.05) in the textural properties of tubers and the thermal and pasting properties of flours among varieties. The degree of cooking and relative firmness of tubers were modelled by a linear equation. The thermal softening behaviour was modelled by a dual‐mechanism first‐order kinetic model with rate constant values ranging from 0.106 to 0.190 min−1. About 69.21% of the total variation in texture profile, gelatinisation and physicochemical parameters could be explained by the first three principal components.

CONCLUSION:The results indicated that the textural and gelatinisation properties varied considerably among different varieties. However, the interaction between the components of the tubers and the structural make‐up of the tuber tissues played a more important role than the physicochemical and functional properties. Copyright © 2008 Society of Chemical Industry
Copolymerization of (Meth)acrylates with Olefins Using Activators Regenerated by Electron Transfer for Atom Transfer Radical Polymerization (ARGET ATRP)
Authors: Tanaka Kenya , Matyjaszewski Krzysztof
Published: January 2008

Summary: Controlled copolymerization of polar (meth)acrylates with non‐polar olefin monomers (1‐octene, norbornene, vinylcyclohexane) was studied by ARGET (activators regenerated by electron transfer) ATRP (atom transfer radical polymerization). When a normal ATRP of n‐butyl acrylate (nBA) and 1‐octene was conducted, the polymerization resulted in relatively low conversion, limited control over the polymerization process and high polydispersity (PDI > 1.6). This was due to formation of a dormant species, by reaction of 1‐octene radicals with Cu(II) deactivator, that could not be reactivated. However, in ARGET ATRP with 10 ppm amounts of Cu‐based catalyst, higher yields and a better controlled copolymerization was obtained (PDI < 1.4), because the low concentration of Cu(II) deactivator reduced the formation of the non‐reactive dormant species. The influence of the amount of Cu catalyst, ligand structure, initiators with different halogens, the reaction temperature, and monomer feed ratio were also investigated for ARGET ATRP. In copolymerization of (meth)acrylates with non‐polar alkenes, the level of control and the total conversion in ARGET ATRP were higher than those for normal ATRP.
Synthesis of Amphiphilic ABCBA‐Type Pentablock Copolymer from Consecutive ATRPs and Self‐Assembly in Aqueous Solution
Authors: Zhang Lifen , Cheng Zhenping , Zhou Nianchen , Zhang Rongmei , Zhu Xiulin
Published: January 2008

Summary: A novel amphiphilic ABCBA‐type pentablock copolymer with properties that are sensitive to temperature and pH, poly(2‐dimethylaminoethyl methacrylate)‐block‐poly(2,2,2‐trifluoroethyl methacrylate)‐block‐poly(ε‐caprolactone)‐block‐poly(2,2,2‐ trifluoroethyl methacrylate)‐block‐poly(2‐dimethylaminoethyl methacrylate) (PDMAEMA‐ b‐PTFEMA‐b‐PCL‐b‐PTFEMA‐b‐PDMAEMA), was synthesized via consecutive atom transfer radical polymerizations (ATRPs). The copolymers obtained were characterized by gel permeation chromatography (GPC) and 1H nuclear magnetic resonance (NMR) spectroscopy, respectively. The aggregation behaviors of the pentablock copolymers in aqueous solution with different pH (pH = 4.0, 7.0 and 8.5) were studied. Transmission electron microscopic images revealed that spherical micelles from self‐assembly of the pentablock copolymer were prevalent in all cases. The mean diameters of these micelles increased from 34, 46, to 119 nm when the pH of the aqueous solution decreased from 8.5, 7.0, to 4.0, respectively.
Polymer Gel Dosimeters with Increased Solubility: A Preliminary Investigation of the NMR and Optical Dose‐Response Using Different Crosslinkers and Co‐Solvents
Authors: Koeva V. I. , Csaszar E. S. , Senden R. J. , McAuley K. B. , Schreiner L. J.
Published: January 2008

Summary: The potential of ten different crosslinkers was investigated, with the aim of improving the performance of polymer gel dosimeters used for detecting radiation dose distributions generated by cancer radiation therapy equipment. Unfortunately, none of the candidate crosslinkers was shown to be more effective than N,N′‐methylene‐bisacrylamide, the standard crosslinker used in polymer gel dosimetry applications. Two co‐solvents, glycerol and isopropanol, were used to increase the solubility of N,N′‐methylene‐bisacrylamide crosslinker in polymer gel dosimeter recipes. Using isopropanol, the crosslinker solubility increased from approximately from 3 to 10% by weight, enabling the manufacture of polymer gel dosimeters with much higher levels of crosslinking than was previously possible. The new dosimeter recipes can be imaged effectively using nuclear magnetic resonance and optical techniques, and may be suitable for read‐out using x‐ray CT (Computed Tomography).
Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand
Authors: Mavric Elvira , Wittmann Silvia , Barth Gerold , Henle Thomas
Published: January 2008

The 1,2‐dicarbonyl compounds 3‐deoxyglucosulose (3‐DG), glyoxal (GO), and methylglyoxal (MGO) were measured as the corresponding quinoxalines after derivatization with orthophenylendiamine using RP‐HPLC and UV‐detection in commercially available honey samples. Whereas for most of the samples values for 3‐DG, MGO, and GO were comparable to previously published data, for six samples of New Zealand Manuka (Leptospermum scoparium) honey very high amounts of MGO were found, ranging from 38 to 761 mg/kg, which is up to 100‐fold higher compared to conventional honeys. MGO was unambigously identified as the corresponding quinoxaline via photodiodearry detection as well as by means of mass spectroscopy. Antibacterial activity of honey and solutions of 1,2‐dicarbonyl towards Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were analyzed using an agar well diffusion assay. Minimum concentrations needed for inhibition of bacterial growth (minimum inhibitory concentration, MIC) of MGO were 1.1 mM for both types of bacteria. MIC for GO was 6.9 mM (E. coli) or 4.3 mM (S. aureus), respectively. 3‐DG showed no inhibition in concentrations up to 60 mM. Whereas most of the honey samples investigated showed no inhibition in dilutions of 80% (v/v with water) or below, the samples of Manuka honey exhibited antibacterial activity when diluted to 15–30%, which corresponded to MGO concentrations of 1.1–1.8 mM. This clearly demonstrates that the pronounced antibacterial activity of New Zealand Manuka honey directly originates from MGO.
An implicit corrected SPH formulation for thermal diffusion with linear free surface boundary conditions
Authors: Schwaiger Hans F.
Published: January 2008

The smoothed particle hydrodynamics (SPH) method has proven useful for modeling large deformation of fluids including fluids with stress‐free surfaces. Because of the Lagrangian nature of the method, it is well suited to address the thermal evolution of these free surface flows. Boundary conditions at the interface of the fluid with a solid wall are usually enforced through the use of boundary particles. However, applying conditions at free surfaces, in particular gradient boundary conditions, can be problematic with traditional SPH formulations due to the degradation of the gradient approximation in these regions. Compounding this difficulty is that traditional approximations of the Laplacian operator suffer a similar degradation near free surfaces. A new SPH formulation of the Laplacian operator is presented, which improves the accuracy near free surface boundaries. This new form is based on a gradient approximation commonly used in thermal, viscous, and pressure projection problems, but includes higher‐order terms in the appropriate Taylor series. Comparisons with other approximations of second‐order derivatives are given. The discretization is tested by solving steady‐state and transient problems of thermal diffusion using the Backward Euler method with a GMRES solver. Boundary conditions are imposed through an augmented matrix. Copyright © 2008 John Wiley & Sons, Ltd.
Mesh adaptive computation of upper and lower bounds in limit analysis
Authors: Ciria H. , Peraire J. , Bonet J.
Published: January 2008

An efficient procedure to compute strict upper and lower bounds for the exact collapse multiplier in limit analysis is presented, with a formulation that explicitly considers the exact convex yield condition. The approach consists of two main steps. First, the continuous problem, under the form of the static principle of limit analysis, is discretized twice (one per bound) using particularly chosen finite element spaces for the stresses and velocities that guarantee the attainment of an upper or a lower bound. The second step consists of solving the resulting discrete non‐linear optimization problems. These are reformulated as second‐order cone programs, which allows for the use of primal–dual interior point methods that optimally exploit the convexity and duality properties of the limit analysis model. To benefit from the fact that collapse mechanisms are typically highly localized, a novel method for adaptive meshing is introduced. The method first decomposes the total bound gap as the sum of positive contributions from each element in the mesh and then refines those elements with higher contributions. The efficiency of the methodology is illustrated with applications in plane stress and plane strain problems. Copyright © 2008 John Wiley & Sons, Ltd.
Solving variational problems by homotopy–perturbation method
Authors: Abdulaziz O. , Hashim I. , Chowdhury M. S. H.
Published: January 2008

In this paper, we consider some problems in calculus of variations. Homotopy–perturbation method (HPM) is adopted to obtain approximate analytical solutions to variational problems. The solutions are obtained in the form of rapidly convergent infinite series with easily computable terms. Numerical results reveal that HPM is very effective and simple for obtaining approximate solutions to variational problems. Copyright © 2008 John Wiley & Sons, Ltd.
New development in extended finite element modeling of large elasto‐plastic deformations
Authors: Anahid M. , Khoei A. R.
Published: January 2008

This paper presents new achievements in the extended finite element modeling of large elasto‐plastic deformation in solid problems. The computational technique is presented based on the extended finite element method (X‐FEM) coupled with the Lagrangian formulation in order to model arbitrary interfaces in large deformations. In X‐FEM, the material interfaces are represented independently of element boundaries, and the process is accomplished by partitioning the domain with some triangular sub‐elements whose Gauss points are used for integration of the domain of elements. The large elasto‐plastic deformation formulation is employed within the X‐FEM framework to simulate the non‐linear behavior of materials. The interface between two bodies is modeled by using the X‐FEM technique and applying the Heaviside‐ and level‐set‐based enrichment functions. Finally, several numerical examples are analyzed, including arbitrary material interfaces, to demonstrate the efficiency of the X‐FEM technique in large plasticity deformations. Copyright © 2008 John Wiley & Sons, Ltd.
Combining differential quadrature method with simulation technique to solve non‐linear differential equations
Authors: Girgin Zekeriya
Published: January 2008

Nowadays, most of the ordinary differential equations (ODEs) can be solved by modelica‐based approaches, such as Matlab/Simulink, Dymola and LabView, which use simulation technique (ST). However, these kinds of approaches restrict the users in the enforcement of conditions at any instant of the time domain. This limitation is one of the most important drawbacks of the ST. Another method of solution, differential quadrature method (DQM), leads to very accurate results using only a few grids on the domain. On the other hand, DQM is not flexible for the solution of non‐linear ODEs and it is not so easy to impose multiple conditions on the same location. For these reasons, the author aims to eliminate the mentioned disadvantages of the simulation technique (ST) and DQM using favorable characteristics of each method in the other. This work aims to show how the combining method (CM) works simply by solving some non‐linear problems and how the CM gives more accurate results compared with those of other methods. Copyright © 2008 John Wiley & Sons, Ltd.
Application of the higher‐order Cauchy–Born rule in mesh‐free continuum and multiscale simulation of carbon nanotubes
Authors: Sun Yuzhou , Liew K. M.
Published: January 2008

This paper investigates the application of a recently proposed higher‐order Cauchy–Born rule in the continuum simulation and multiscale analysis of carbon nanotubes (CNTs). A mesh‐free computational framework is developed to implement the numerical computation of the hyper‐elastic constitutive model that is derived from the higher‐order Cauchy–Born rule. The numerical computation reveals that the buckling pattern of a single‐walled carbon nanotube (SWCNT) can be accurately displayed by taking into consideration the second‐order deformation gradient, and fewer mesh‐free nodes can provide a good simulation of homogeneous deformation. The bridging domain method is employed to couple the developed mesh‐free method and the atomistic simulation. The coupling method is used to simulate the bending buckling of an SWCNT and the tensile failure of an SWCNT with a single‐atom vacancy defect, and good computational results are obtained. Copyright © 2008 John Wiley & Sons, Ltd.
Automated technologies and novel techniques to accelerate protein crystallography for structural genomics
Authors: Manjasetty Babu A. , Turnbull Andrew P. , Panjikar Santosh , Büssow Konrad , Chance Mark R.
Published: January 2008

The sequence infrastructure that has arisen through large‐scale genomic projects dedicated to protein analysis, has provided a wealth of information and brought together scientists and institutions from all over the world. As a consequence, the development of novel technologies and methodologies in proteomics research is helping to unravel the biochemical and physiological mechanisms of complex multivariate diseases at both a functional and molecular level. In the late sixties, when X‐ray crystallography had just been established, the idea of determining protein structure on an almost universal basis was akin to an impossible dream or a miracle. Yet only forty years after, automated protein structure determination platforms have been established. The widespread use of robotics in protein crystallography has had a huge impact at every stage of the pipeline from protein cloning, over‐expression, purification, crystallization, data collection, structure solution, refinement, validation and data management‐ all of which have become more or less automated with minimal human intervention necessary. Here, recent advances in protein crystal structure analysis in the context of structural genomics will be discussed. In addition, this review aims to give an overview of recent developments in high throughput instrumentation, and technologies and strategies to accelerate protein structure/function analysis.
Kinetics and mechanism of the reaction between 4‐hexadecylbenzenediazonium ions and vitamin C in emulsions: further evidence of the formation of diazo ether intermediates in the course of the reaction
Authors: Pastoriza‐Gallego María José , Fernández‐Alonso Alejandra , Losada‐Barreiro Sonia , Sánchez‐Paz Verónica , Bravo‐Díaz Carlos
Published: January 2008

The kinetics and mechanism of the reaction between hydrophobic 4‐hexadecylarenediazonium ions, 16‐ArN and vitamin C, VC, in a model emulsion prepared by mixing octane, acidic (HCl) water and the non‐ionic surfactant hexaethyleneglycol monododecyl ether, C12E6, were investigated. Because emulsions are opaque, linear sweep voltammetry, LSV, was employed to monitor the reaction. Voltammograms of 16‐ArN in emulsions show two reduction peaks as in aqueous systems. The half‐life for the spontaneous decomposition of 16‐ArN in the emulsion was estimated as t1/2 = 14.5 h at T = 25 °C. Upon addition of VC to the system, the first reduction peak of 16‐ArN disappears almost immediately and a new reduction peak is detected at Ep = −0.25 V. Electrochemical titration of 16‐ArN shows that the new peak corresponds to the formation of a 1:1 adduct. The iP(Ep = −0.25 V) values can be linearly correlated with [16‐ArN] and the observed rate constants, kobs, were determined by fitting the (ip, t) data to the integrated first order equation. The variation of kobs with [VC] follows a saturation kinetics profile, consistent with the formation of an intermediate in a pre‐equilibrium step. All the evidence is consistent with a reaction mechanism comprising two competitive pathways, the spontaneous DN + AN mechanism and the unimolecular decomposition of a transient diazo ether (DE) formed in a pre‐equilibrium step. The data allowed estimations of the interfacial rate constant for the reaction between 16‐ArN and VC− but did not allow the determination of the equilibrium constant for the DE formation. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of 2,3‐dimethyl‐2,3‐diisobutyl succinonitrile in laser printer emissions
Authors: Barrero‐Moreno Josefa M. , Tirendi Salvatore , Reniero Fabiano , Giordano Giuseppe , Kotzias Dimitrios
Published: January 2008

2,3‐Dimethyl‐2,3‐diisobutyl succinonitrile was identified as the main volatile organic compound (>90%) emitted from laser printers during the printing process. Experiments were carried out in a large environmental chamber of 30 m3, where the printers were placed and working simulating ‘real office setting’ conditions. Air samples were taken on Tenax TA adsorbent cartridges in the vicinity of the printers and further analyzed by thermal desorption gas chromatography/mass spectrometry (TDGC/MS). The structure of the compound has been determined and is presented in this study. Additional data obtained by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and liquid chromatography/tandem mass spectrometry (LC/MS/MS) support the proposed structure, with no reported CAS number, as 2,3‐dimethyl‐2,3‐diisobutyl succinonitrile. It is a byproduct of the thermal decomposition of 2,2′‐azobis(2,4‐dimethyl valeronitrile), a commercially available free radical polymerization initiator used in polymerization processes during the manufacture of the toners. By means of head‐space GC/MS, 15 toners used in black & white and colour printers have been investigated. Six of them contained 2,3‐dimethyl‐2,3‐diisobutyl succinonitrile, which has also been detected in the respective processed paper. Copyright © 2008 John Wiley & Sons, Ltd.
On the globally defined sensorless control of induction motors
Authors: Guerrero C. , Espinosa‐Pérez G. , Moreno J. A. , Álvarez‐Salas R.
Published: January 2008

The sensorless control problem of induction motors imposes a current challenge since the nonlinear model of this kind of machines does not exhibit global observability properties, i.e. there are some operation regimes for which speed observability is lost. One way for dealing with this unavoidable limitation, and at the same time provide globally defined controllers, is to consider that the rotor variables are estimated via an open‐loop observer. In this paper a globally defined passivity‐based speed controller that belongs to the aforementioned class is presented. It is shown that the structure of previously reported passivity‐based controllers, developed under the assumption that the mechanical variables are available for measurement, can be extended to operate under sensorless conditions if a speed observer is included in the control scheme. Since the controller design methodology leads to inherent drawbacks regarding robustness issues, to evaluate the usefulness of the proposed scheme a numerically based study is included that cover topics such as parameters and disturbance (load torque) uncertainty. The advantages and limitations of the proposed scheme are established with respect to other globally defined sensorless controllers. Copyright © 2008 John Wiley & Sons, Ltd.
A new controller for the inverted pendulum on a cart
Authors: Gordillo F. , Aracil J.
Published: January 2008

This paper presents a complete solution to the problem of swinging‐up and stabilization of the inverted pendulum on a cart, with a single control law. The resulting law has two parts: first, an energy‐shaping law is able to swing and maintain the pendulum up. Then, the second part introduces additional control to stop the cart and it is based on forwarding control with bounded input. The resulting control law is the sum of both parts and does not commute between different laws although there exist switches inside the controller. Copyright © 2008 John Wiley & Sons, Ltd.
ANODIC formation of thin Cu(I) and Ag(I) oxide films on Cu‐Au and Ag—Au alloys
Authors: Vvedenskii Alexander , Grushevskaya Svetlana , Kudryashov Dmitrii
Published: January 2008

The anodic dissolution of Cu, Ag and their alloys with gold under the conditions of the formation of copper or silver oxides was examined by the technique of cyclic voltammetry, chronoammetry and photopotential measurements. The anodic formation and cathodic reduction of Cu(I) oxide on copper and Cu‐Au alloys or Ag(I) oxide on silver and Ag‐Au alloys with XAu≤30 at.% are controlled by migration in the oxide film. The peculiarity of Ag‐Au system is connected with the duplex structure of the oxide film and the initial selective dissolution of silver from Ag15Au and Ag30Au alloys. Ag2O oxide is an n‐type semiconductor with an excess of silver atoms. Oxide layers formed on monocrystalline silver are more stoichiometric than the layer formed on polycrystalline Ag. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation, Crystal Structure, Physical Properties and Electronic Band Structure of TlScQ2 (Q = S, Se and Te)
Authors: Teske Christoph L. , Bensch Wolfgang , Mankovsky Sergey , Ebert Hubert
Published: January 2008

The title compounds were prepared by reaction of Tl2Q (Q = S, Se and Te) Sc and Q in the temperature range of 200 to 500 °C. The structures of the selenide and the telluride adopt the α‐NaFeO2 type, while TlScS2 crystallizes in the β‐RbScO2 type structure. The space group is $\rm R{\bar 3}\rm m$ for TlScSe2 and TlScTe2 with a = 3.9370(4) Å, c = 23.194(5) Å, and a = 4.2129(4) Å, c = 24.099(3) Å, respectively. The sulphide crystallizes in P63/mmc with a = 3.761(3) Å and c = 14.942(4) Å. The crystal chemical relations between the three chalcogenides are discussed. According to the electrical measurements and the band structure calculations, the compounds are semiconductors or poor metals.
Trivalent‐Intermediate Valent Cerium Ordering in Ce2RuZn4
Authors: Mishra Ratikanta , Hermes Wilfried , Rodewald Ute Ch. , Hoffmann Rolf‐Dieter , Pöttgen Rainer
Published: January 2008

The new intermetallic cerium compound Ce2RuZn4 was synthesized from the elements in a sealed tantalum tube in a water‐cooled sample chamber of an induction furnace. Ce2RuZn4 crystallizes with a new structure type: P4/nmm, Z = 2, a = 719.6(1), c = 520.2(1) pm, wR2 = 0.0816, 273 F2 values and 15 variables. The structure contains two crystallographically independent cerium atoms: Ce1 with CN 16 (12 Zn + 4 Ce) and Ce2 with CN 14 (2 Ru + 8 Zn + 4 Ce). Based on the interatomic distances the two sites can be assigned to trivalent Ce1 and intermediate valent Ce2. The trivalent‐intermediate valent cerium ordering is underlined by magnetic susceptibility measurements. Ce2RuZn4 shows modified Curie‐Weiss behaviour in the temperature range 10–290 K with an experimental magnetic moment of 2.57(1) μB per formula unit. Thus only half of the cerium atoms are trivalent in Ce2RuZn4. A remarkable feature of the Ce2RuZn4 structure are short Ce2–Ru distances of 260 pm. The crystal chemistry of Ce2RuZn4 is discussed.
Supramolecular Stuctures from Mononuclear, Binuclear and 2D Net of Copper(II) Complexes with 6‐Hydroxypicolinic Acid
Authors: Sun Chang‐Yan , Zhou Jie , Li Wen‐Jun , Jin Lin‐Pei
Published: January 2008

First examples of transition metal complexes with HpicOH [Cu(picOH)2(H2O)2] (1), [Cu(picO)(2,2′‐bpy)]·2H2O (2), [Cu(picO)(4,4′‐bpy)0.5(H2O)]n (3), and [Cu(picO)(bpe)0.5(H2O)]n (4) (HpicOH = 6‐hydroxy‐picolinic acid; 2,2′‐bpy = 2,2′‐bipyridine; 4,4′‐bpy = 4,4′‐bipyridine; bpe = 1,2‐bis(4‐pyridyl)ethane) have been synthesized and characterized by single‐crystal X‐ray diffraction. The results show that HpicOH ligand can be in the enol or ketonic form, and adopts different coordination modes under different pH value of the reaction mixture. In complex 1, HpicOH ligand is in the enol form and adopts a bidentate mode. While in complexes 2–4, as the pH rises, HpicOH ligand becomes in the ketonic form and adopts a tridentate mode. The coordination modes in complexes 1–4 have not been reported before. Because of the introduction of the terminal ligands 2,2′‐bpy, complex 2 is of binuclear species; whereas in complexes 3 and 4, picO ligands together with bridging ligands 4,4′‐bpy and bpe connect CuII ions to form 2D nets with (123)2(12)3 topology.
Synthesis and Crystal Structure of an Oligomeric Lithium Bis(amido)hydridooxidoaluminate Cluster, [{Li(C14H30N2)AlHO1/2}4]
Authors: Gardiner Michael G. , Raston Colin L.
Published: January 2008

The lithium bis(amido)hydridooxidoaluminate cluster [{Li(C14H30N2)AlHO1/2}4] has been synthesized during systematic metallation/hydrometallation studies of a series of 1,4‐diazabut‐1‐enes with lithium aluminiumhydride. Formation of the complex is presumably derived from partial hydrolysis of the related lithium bis(amido)dihydridoaluminate and has been characterized using single crystal X‐ray diffraction. The complex crystallizes in the monoclinic space group C2/c (No. 15) with a = 25.012(2) Å, b = 10.673(2) Å, c = 28.673(3) Å, β = 115.855(7)°, V = 6887(1) Å3, Z = 4. The complex exhibits an oligomeric structure of crystallographic C2 symmetry, comprised of complex multicyclic units arising from extensive metal, hydride, oxide and ligand bridging interactions. These associations give rise to edge‐fused, non‐planar NAlOLi four‐membered rings tightly binding two of the diamido‐chelated aluminate units, with these in turn aggregating further via two of the μ2‐hydrides involving lithium atoms.
Synthesis, Crystal Structure, and Emission Spectra of Lanthanum(III) Coordination Polymer with 1,5‐Naphthalenedisulfonate Ligand
Authors: Deng Zhao‐Peng , Gao Shan , Zhu Zhi‐Biao , Huo Li‐Hua
Published: January 2008

The first two‐dimensional lanthanum(III) coordination polymer, [La(1,5‐NDS)1.5(H2O)5]n (1) (1,5‐NDS2− = 1,5‐naphthalenedisulfonate), was synthesized and structurally characterized by single‐crystal X‐ray diffraction analysis. The disulfonate ligands act in the η1:η1:μ2 and η1:η1:η1:μ3 binding modes to link the LaO9 tricapped trigonal prisms into a lamellar structure. It exhibits strong purple emission in the solid state.
Clinical Application of Layered Anastomosis During Esophagogastrostomy
Authors: Zhu Zi‐Jiang , Zhao Yong‐Fan , Chen Long‐Qi , Hu Yang , Liu Lun‐Xu , Wang Yun , Kou Ying‐Li
Published: January 2008

The aim of this study was to compare the operative results in regard to reducing anastomotic leakage and stricture formation using a newly designed layered manual esophagogastric anastomosis versus a stapler esophagogastrostomy versus the conventional hand‐sewn whole‐layer anastomosis after resection for esophageal or gastric cardiac carcinoma. From January 2004 to September 2006, a total of 1024 patients with esophageal or gastric cardia carcinoma underwent a layered esophagogastric anastomosis with the assistance of a three‐leaf clipper in a single university medical center. The mucosal layers of the esophagus and stomach were sutured continuously with 4/0 Vicryl plus antibacterial suture (polyglyconate). From May 2002 to December 2003, there were also 170 patients and 69 patients who underwent stapler and conventional whole‐layer anastomosis, respectively; they served as control groups. The results were analyzed retrospectively. The operative mortality rate was 0.7% in the layered group compared to 5.9% and 7.2% for the stapler group and the whole‐layer group (p < 0.01), The anastomotic leakage rates were 0%, 3.5%, and 5.8% for the layered group, stapler group, and whole‐layer group, respectively (p < 0.01). All patients were followed postoperatively. Six patients in the layered group (0.6%) developed mild stricture formation compared to 16 patients in stapled group (9.9%) and 5 patients in the conventional whole‐layer group (7.8%) (p < 0.01). The application of layered esophagogastric anastomosis could reduce the incidence of anastomotic leakage and stricture after esophagectomy compared with the stapler and whole‐layer manual anastomoses. It is easy to apply and could be used as an alternative for esophagogastric anastomosis after resection for esophageal or cardiac carcinoma.
Bacterial population dynamics and faecal short-chain fatty acid (SCFA) concentrations in healthy humans
Authors: McOrist Alexandra L. , Abell Guy C. J. , Cooke Caroline , Nyland Kerry
Published: January 2008

Fermentation products, SCFA, particularly butyrate, are considered a sign of ‘good’ bowel health but the influence of bacterial population composition and diet on inter-individual difference in metabolites and colonic health is poorly understood. Faecal specimens were collected weekly from eight healthy human volunteers over 12 weeks. Dietary intake was self-reported and ten macronutrient factors were analysed at selected weekly periods. Faecal weight, pH and moisture were recorded, and SCFA concentrations were measured in all samples. From each specimen, DNA was prepared and eubacterial 16S rRNA gene PCR performed. Bacterial population profiles were captured by denaturing gradient gel electrophoresis (DGGE) of PCR products, and multivariate statistical analysis was performed. Faecal weight, pH and moisture varied widely within and between individuals. Average total SCFA concentrations over 12 weeks ranged from 36·9 to 144·4 mmol/kg in 48 h specimens and faecal butyrate concentrations ranged from 1·8 to 48·5 mmol/kg. Two individuals with butyrate concentrations below 10 mmol/kg were considered to be ‘low butyrate types’ and may represent an at-risk population for bowel health. Dietary fat, sugar and carbohydrate showed weak correlation with SCFA (R− 0·612,P = 0·015;R0·607,P = 0·016;R0·610,P = 0·016, respectively) and butyrate concentrations (R− 0·593,P = 0·02;R0·504,P = 0·054;R0·528,P = 0·043, respectively). Multivariate analysis of DGGE bacterial profiles demonstrated concise and repeated grouping of intra-individual samples, but these were combined with distinct inter-individual differences (analysis of similaritiesP < 0·001,R ≥ 0·99) The exact relationship of these SCFA values to the overall bacterial profiles and SCFA-producer bacterial groups was not direct nor linear.
An arachidonic acid-enriched diet does not result in more colonic inflammation as compared with fish oil- or oleic acid-enriched diets in mice with experimental colitis
Authors: Ramakers Julian D. , Mensink Ronald P. , Verstege Marleen I. , te Velde Anje A. , Plat Jogchum
Published: January 2008

Fish oils (FO) – rich in EPA and DHA – may protect against colitis development. Moreover, inflammatory bowel disease patients have elevated colonic arachidonic acid (AA) proportions. So far, effects of dietary AAv.FO on colitis have never been examined. We therefore designed three isoenergetic diets, which were fed to mice for 6 weeks preceding and during 7 d dextran sodium sulfate colitis induction. The control diet was rich in oleic acid (OA). For the other two diets, 1·0 % (w/w) OA was exchanged for EPA+DHA (FO group) or AA. At 7 d after colitis induction, the AA group had gained weight (0·46 (sem0·54) g), whereas the FO and OA groups had lost weight ( − 0·98 (sem0·81) g and − 0·79 (sem1·05) g, respectively;P < 0·01v.AA). The AA group had less diarrhoea than the FO and OA groups (P < 0·05). Weight and length of the colon, histological scores and cytokine concentrations in colon homogenates showed no differences. Myeloperoxidase concentrations in plasma and polymorphonuclear cell infiltration in colon were decreased in the FO group as compared with the OA group. We conclude that in this mice model an AA-enriched diet increased colonic AA content, but did not result in more colonic inflammation as compared with FO- and OA-enriched diets. As we only examined effects after 7 d and because the time point for evaluating effects seems to be important, the present results should be regarded as preliminary. Future studies should further elucidate differential effects of fatty acids on colitis development in time.
The distribution ofFasciola hepaticaandFasciola giganticawithin southern Tanzania – constraints associated with the intermediate host
Authors: WALKER S. M. , MAKUNDI A. E. , NAMUBA F. V. , KASSUKU A. A. , KEYYU J. , HOEY E. M. , PRÖDOHL P. , STOTHARD J. R. , TRUDGETT A.
Published: January 2008

In East Africa,Fasciola giganticais generally the causative agent of fasciolosis but there have been reports ofF. hepaticain cattle from highland regions of Kenya, Ethiopia, Uganda and Zaire. The topography of the Southern Highlands of Tanzania provides an environment where the climatic conditions exist for the sustenance of lymnaeid species capable of supporting bothFasciola hepaticaandF. gigantica. Theoretically this would allow interaction between fasciolid species and the possible creation of hybrids. In this report we present molecular data confirming the existence of the snail,Lymnaea truncatula, at high altitude on the Kitulo Plateau of the Southern Highlands, Tanzania, along with morphometric and molecular data confirming the presence ofF. hepaticain the corresponding area. At lower altitudes, where climatic conditions were unfavourable for the existence ofL. truncatula, the presence of its sister speciesL. natalensiswas confirmed by molecular data along with its preferred fasciolid parasite,F. gigantica. Analysis based on a 618 bp sequence of the 28S rRNA gene did not reveal the presence of hybrid fasciolids in our fluke samples.
Mental disorders and personality traits as determinants of impaired work functioning
Authors: Michon H. W. C. , ten Have M. , Kroon H. , van Weeghel J. , de Graaf R. , Schene A. H.
Published: January 2008

Background

Both mental disorders and personality characteristics are associated with impaired work functioning, but these determinants have not yet been studied together. The aim of this paper is to examine the impairing effects that mental disorders and personality characteristics (i.e. neuroticism, locus of control and self-esteem) have on work functioning.

Method

Data for a representative sample of 3570 working people were derived from the first two waves of the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a prospective cohort study in the Dutch adult population.

Results

Higher neuroticism, more external locus of control and lower self-esteem were each significantly associated with subsequent impairment in work functioning, independently of any effects from mental disorders. Associations between mental disorders and subsequent work impairment disappeared once personality traits were taken into account. Personality traits did not moderate the relationships between mental disorders and work functioning.

Conclusions

Working people with vulnerable personalities have a greater risk of impaired work functioning, independent of the risk from any mental disorder they may have.
The long-term longitudinal course of oppositional defiant disorder and conduct disorder in ADHD boys: findings from a controlled 10-year prospective longitudinal follow-up study
Authors: Biederman J. , Petty C. R. , Dolan C. , Hughes S. , Mick E. , Monuteaux M. C. , Faraone S. V.
Published: January 2008

Background

A better understanding of the long-term scope and impact of the co-morbidity with oppositional defiant disorder (ODD) and conduct disorder (CD) in attention deficit hyperactivity disorder (ADHD) youth has important clinical and public health implications.

Method

Subjects were assessed blindly at baseline (mean age=10.7 years), 1-year (mean age=11.9 years), 4-year (mean age=14.7 years) and 10-year follow-up (mean age=21.7 years). The subjects' lifetime diagnostic status of ADHD, ODD and CD by the 4-year follow-up were used to define four groups (Controls, ADHD, ADHD plus ODD, and ADHD plus ODD and CD). Diagnostic outcomes at the 10-year follow-up were considered positive if full criteria were met any time after the 4-year assessment (interval diagnosis). Outcomes were examined using a Kaplan–Meier survival function (persistence of ODD), logistic regression (for binary outcomes) and negative binomial regression (for count outcomes) controlling for age.

Results

ODD persisted in a substantial minority of subjects at the 10-year follow-up. Independent of co-morbid CD, ODD was associated with major depression in the interval between the 4-year and the 10-year follow-up. Although ODD significantly increased the risk for CD and antisocial personality disorder, CD conferred a much larger risk for these outcomes. Furthermore, only CD was associated with significantly increased risk for psychoactive substance use disorders, smoking, and bipolar disorder.

Conclusions

These longitudinal findings support and extend previously reported findings from this sample at the 4-year follow-up indicating that ODD and CD follow a divergent course. They also support previous findings that ODD heralds a compromised outcome for ADHD youth grown up independently of the co-morbidity with CD.
M-deformations of -simple germs from to
Authors: RIEGER J. H. , RUAS M. A. S. , ATIQUE R. WIK
Published: January 2008

All{\cA}-simple corank-1 germs from$\bR ^n$to$\bR ^{n+1}$, wheren≠ 4, have an M-deformation, that is a deformation in which the maximal numbers of isolated stable singular points are simultaneously present in the image.