bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors influencing physicians' detection of cancer patients' and relatives' distress: can a communication skills training program improve physicians' detection?
Authors: Merckaert Isabelle , Libert Yves , Delvaux Nicole , Marchal Serge , Boniver Jacques , Etienne Anne‐Marie , Klastersky Jean , Reynaert Christine , Scalliet Pierre , Slachmuylder Jean‐Louis , Razavi Darius
Published: June 2007

Purpose: This study aimed to assess the impact on physicians' detection of patients' and relatives' distress of six 3‐h consolidation workshops (CW) following a 2.5‐day communication skills basic training (BT) program and to investigate factors associated with detection of distress.

Methods: Physicians, after BT, were randomized to CW or to a waiting list. Physicians' detection of patients' and relatives' distress was measured through differences between physicians' ratings of patients' and relatives' distress (VAS) and patients' and relatives' self‐reported distress (HADS). Communication skills were analysed according to the CRCWEM.

Results: Mixed‐effects modelling of physicians' detection of patients' distress showed a positive group by time effect in favour of physicians in the CW group. Detection of patients' distress was associated negatively with patients' distress, positively with physicians' concurrent use of psychological assessment and supportive skills, and negatively with general assessment skills. Mixed‐effects modelling of physicians' detection of relatives' distress showed no significant group by time effect. Detection of relatives' distress was associated negatively with relatives' distress and with general assessment skills.

Conclusion: CW following a 2.5‐day BT are needed to improve physicians' detection of patients' distress in three‐person interviews. Results indicate the need to further improve physicians' detection of relatives' distress. Copyright © 2007 John Wiley & Sons, Ltd.
Visibility of misfit dislocations at the interface of strained Si/Si0.8Ge0.2 by EBIC
Authors: Yuan X. L. , Chen J. , Ri S. G. , Ito S. , Sekiguchi T.
Published: June 2007

We have characterized dislocations in strained‐Si/SiGe heterostructures with different doping concentration by using electron beam induced current (EBIC). Lower energy (4 keV) electron beam was used to observe the defects, namely misfit dislocations (MDs) and threading dislocations (TDs) at the interface of strained‐Si/SiGe. Fine dark lines and dark dots were appeared in the 4 keV EBIC images below 100 K. It was found that the visibility of MDs at the upper interface depends on the specimen structure and doping concentration. The results were analyzed in term of the internal electric field related to the doping concentration in samples. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
CdSe/ZnSe heteroepitaxy: Aspects of growth and self organization of nanostructures
Authors: Mahapatra S. , Kiessling T. , Margapoti E. , Astakhov G. V. , Renner J. , Bass U. , Bougerol C. , Schmidt T. , Bendounan A. , Schmitt F. , Schumacher C. , Worschech L. , Ossau W. , Geurts J. , Molenkamp L. W. , Reinert F. , Forchel A. , Brunner K.
Published: June 2007

Formation and properties of quantum dots (QDs) and related nanostructures by conventional molecular beam epitaxy (MBE) and two other variants of the technique, have been systematically investigated. While MBE growth of CdSe on ZnSe at 300 °C results in the formation of rough CdSe quantum‐well‐like structures, by one of the variants, which combines epitaxial growth of a CdSe layer at 230 °C and subsequent in‐situ annealing at 310‐340 °C, tiny but distinct three‐dimensional (3D) QDs are formed. We demonstrate that QD formation by this method, developed originally by Rabe et al. (J. Cryst. Growth 184/185, 248 (1998) [30]), essentially takes place during the annealing step, by a process of “controlled roughening” of the as‐grown quasi‐two‐dimensional (2D) CdSe layer. In comparison to conventional MBE, this process results in reduction of the areal density of the self‐organized QDs by up to two orders of magnitude, thus making them distinctly discernible. In the second variant technique, similar to that applied originally for the self‐organization of CdTe/ZnTe quantum dots by Tinjod et al. (Appl. Phys. Lett. 82, 4340 (2003) [34], QD‐formation takes place as a result of deposition of an amorphous group‐VI layer onto a strained 2D CdSe layer at ∼ 50 °C, and its subsequent re‐desorption at temperatures of 280‐320 °C. While deposition and desorption of amorphous Se leads to the formation of large isolated QDs, we show that use of amorphous Te results in the self‐assembly and ordering of a rich variety of nanostructures. Luminescence, morphology, and composition of QDs and the underlying formation mechanism of the three processes are discussed in detail. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Model computations for Cd adsorption on the (001) surface of CdTe
Authors: Patrakov A. E. , Fink R. F. , Fink K. , Engels B.
Published: June 2007

It is investigated whether cluster models can be used to describe the (001) CdTe (2×1) reconstructed surface and adsorption of Cd atoms on three different sites upon it. Surface structures and the cadmium binding energies are evaluated for clusters of different size and by slab calculations. While the structure of the pure surface depends only weakly on the surface model, a proper structure of the most stable adsorption site requires inclusion of at least the fourth next neighbor to the adsorbed Cd atom. Prediction of the structure of less bound adsorption sites is shown to be also possible with cluster models but in this case particular care has to be spent to avoid asymmetric distortions or non‐realistic geometries due to border effects of the cluster. The binding energy of a Cd atom on the (001) CdTe (2×1) surface is predicted to be 1.9‐2.1 eV. The motion of a Cd atom in (100)‐direction (along Te‐Te dimer rows) is unlikely as it requires about all of the binding energy. Adsorption of a Cd atom between two Te‐dimer rows probably leads to a reconstruction of the dimer structure. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High power and high efficiency green light emitting diode on free‐standing semipolar (11$ \bar 2 $2) bulk GaN substrate
Authors: Sato Hitoshi , Tyagi Anurag , Zhong Hong , Fellows Natalie , Chung Roy B. , Saito Makoto , Fujito Kenji , Speck James S. , DenBaars Steven P. , Nakamura Shuji
Published: June 2007

We demonstrate a high power green InGaN/GaN multiple‐quantum‐well (MQW) light emitting diode (LED) with a peak emission wavelength of 516 nm grown on low extended defect density semipolar (11$ \bar 2 $2) bulk GaN substrate by metal organic chemical vapor deposition. The output power and external quantum efficiency (EQE) at drive currents of 20 and 100 mA under direct current (DC) operation were 5.0 mW, 10.5% and 15.6 mW, 6.3%, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mimicry of phase I drug metabolism – novel methods for metabolite characterization and synthesis
Authors: Johansson Tove , Weidolf Lars , Jurva Ulrik
Published: June 2007

The extent to which electrochemical oxidation, electrochemically assisted Fenton chemistry and synthetic metalloporphines can be used to mimic cytochrome P450 catalyzed oxidations has been investigated for a large range of metabolic reactions. Most relevant metabolic oxidations can be mimicked by at least one of the three investigated systems. The EC oxidation system successfully mimics benzylic hydroxylation, hydroxylation of aromatic rings containing electron‐donating groups, N‐dealkylation, S‐oxidation, dehydrogenation and less efficiently N‐oxidation and O‐dealkylation. The EC‐Fenton system is able to mimic aliphatic hydroxylation, benzylic hydroxylation, aromatic hydroxylation, N‐dealkylation, N‐oxidation, O‐dealkylation, S‐oxidation and dehydrogenation. The porphine system mimics all types of reactions although the yields are low for some reactions. In conclusion, these three complementary systems can be used during the drug discovery and development of new drugs to elucidate the structure of metabolites that are difficult to characterize in biological matrices. Moreover, such techniques can replace the classical chemistry strategy, especially when synthesis is complicated or too time‐consuming in order to access metabolites for further testing. Copyright © 2007 John Wiley & Sons, Ltd.
Versatile inlet system for on‐line compound‐specific δD and δ13C gas chromatography–oxidation/reduction–isotope ratio mass spectrometry analysis of gaseous mixtures
Authors: Henning Mark , Strąpoć Dariusz , Lis Grzegorz P. , Sauer Peter , Fong Jon , Schimmelmann Arndt , Pratt Lisa M.
Published: June 2007

Compound‐specific δD and δ13C analyses of gas mixtures are useful indicators of geochemical and environmental factors. However, the relative concentrations of individual components in gas mixtures (e.g., H2, CO2, methane, ethane, propane, i‐butane, n‐butane) may vary over several orders of magnitude. The determination of hydrogen and carbon compound‐specific stable isotope ratios requires that the hydrogen and carbon dioxide produced from each separated component has a concentration adjusted to match the dynamic range of the stable isotope mass spectrometer. We present a custom‐built gas sampling and injection system (GASIS) linked with a Delta Plus XP mass spectrometer that provides flexibility, ease of operation, and economical use of small gas samples with wide ranges of analyte concentrations. The overall on‐line GC‐ox/red‐IRMS (Gas Chromatography – oxidation/reduction – Isotope Ratio Mass Spectrometry) system consists of (i) a customized GASIS inlet system and (ii) two alternative reactors, namely an oxidative Cu‐Ni‐Pt reactor at 950°C for production of CO2 and a reductive graphitized Al2O3 reactor at 1420°C for production of H2. In addition, the system is equipped with (iii) a liquid nitrogen spray‐cooling unit for cryo‐GC‐focusing at −20°C, and (iv) a Nafion® dryer for removal of water vapor from product CO2. The three injection loops of the GASIS inlet allow flexibility in the volume of injected analyte gas (e.g., from 0.06 to 500 µL) in order to measure reproducible δD and δ13C values for gases at concentrations ranging from 100% down to 10 ppm. We calibrate our GC‐ox/red‐IRMS system with two isotopically distinct methane references gases that are combusted off‐line and characterized using dual‐inlet IRMS. Copyright © 2007 John Wiley & Sons, Ltd.
Gas‐phase fragmentation of protonated benzodiazepines
Authors: Risoli Antonella , Cheng Joey B. Y. , Verkerk Udo H. , Zhao Junfang , Ragno Gaetano , Hopkinson Alan C. , Siu K. W. Michael
Published: June 2007

Protonated 1,4‐benzodiazepines dissociate in the gas phase by the common pathway of CO elimination and by unique pathways dictated by the substituents; the latter typically differentiate one benzodiazepine from another. Protonated 3‐dihydro‐5‐phenyl‐1,4‐benzodiazepin‐2‐one, the base diazepam devoid of substituents, dissociates by eliminating CO, HNCO, benzene, and benzonitrile. Mechanisms of these reactions are proposed with ionic products being resonance stabilized. The abundant [MH−CO]+ion dissociates to secondary products via elimination of benzene, benzonitrile, the NH2radical, and ammonia, yielding again ionic products that are stabilized by resonance. Copyright © 2007 John Wiley & Sons, Ltd.
Development and validation of a multiresidue method for the analysis of 151 pesticide residues in strawberry by gas chromatography coupled to a triple quadrupole mass analyzer
Authors: Bolaños Patricia Plaza , Moreno José Luis Fernández , Shtereva Deyana D. , Frenich Antonia Garrido , Vidal José Luis Martínez
Published: June 2007

A new method was developed and validated for the simultaneous determination of 151 pesticide residues in strawberry by gas chromatography coupled to a triple quadrupole mass analyzer (GC/QqQ‐MS/MS), mainly using the selected reaction monitoring (SRM) mode. The list of target compounds included various classes of pesticides such as organochlorine (OCPs), organophosphorus (OPPs), carbamates, pyrethroids, triazoles and dicarboximides. A single extraction of 10 g of sample with acetonitrile followed by liquid‐liquid partition formed by the addition of 4 g of MgSO4 and 1 g of NaCl was applied in sample preparation. Cleanup of the extracts was carried out by applying dispersive solid‐phase extraction (D‐SPE) with primary secondary amine (PSA). The analysis time was 21 min. The method was subjected to a thorough validation procedure. The recovery data were obtained by spiking blank samples at two concentration levels (11.5 and 50 µg/kg), yielding recoveries in the range 70–110%. Precision values expressed as relative standard deviation (RSD) were lower than 18% and 22% for the intraday and interday precision, respectively. Linearity was studied in the range 10–200 µg/kg and determination coefficients (R2) were higher than 0.98% for all compounds. Limits of detection (LODs) and limits of quantification (LOQs) were established as 4 and 10 µg/kg, respectively. The overall uncertainty of the method was estimated at two different concentrations (11.5 and 50 µg/kg), being lower than 25% in both cases. According to the validation data and performance characteristics as well as the high sample throughput and low cost, the proposed method is suitable for routine application. Copyright © 2007 John Wiley & Sons, Ltd.
Investigating thein vitrometabolism of fipexide: characterization of reactive metabolites using liquid chromatography/mass spectrometry
Authors: Sleno Lekha , Staack Roland F. , Varesio Emmanuel , Hopfgartner Gérard
Published: June 2007

Thein vitrometabolism of the nootropic drug fipexide was studied using different liquid chromatography/mass spectrometry (LC/MS) techniques. This drug has been withdrawn from the market due to toxic effects. No previous reports have investigated the possible involvement of reactive metabolites in the toxicity of fipexide. The hydrolysis of this drug leads to the formation of two potentially toxic species, 3,4‐methylenedioxybenzylpiperazine (MDBP) and 4‐chlorophenoxyacetic acid (4‐CPA). Here, we investigate thein vitrometabolism of fipexide in human, rat, mouse and dog, as well as of MDBP and 4‐CPA in human and rat, while focusing on the formation of reactive metabolites. A combination of LC/MS analyses on a hybrid quadrupole‐linear ion trap instrument and accurate mass data from QqTOF measurements was employed for the characterization of these metabolites. Microsomal metabolites of fipexide were MDBP, 4‐CPA, fipexideN‐oxide or hydroxyl, demethylenated fipexide and other minor ones, all of which were investigated by tandem mass spectrometry. Reactive metabolites were detected using several trapping procedures with small molecules such as glutathione, its ethyl ester derivative andN‐acetylcysteine. The demethylenated metabolite, a catechol, formed its correspondingortho‐quinone, which readily reacts with these nucleophiles. MDBP was studied in a similar manner, due to its ability to form an analogous catechol. Because of its acidic nature, 4‐CPA was assessed for possible acylglucuronide and acyl‐CoA thioester metabolites, which could also be involved in bioactivation pathways. Several important metabolites were identified as potential mediators of toxicity via protein binding. Copyright © 2007 John Wiley & Sons, Ltd.
Validated assay for the simultaneous determination of the anti‐cancer agent gemcitabine and its metabolite 2′,2′‐difluorodeoxyuridine in human plasma by high‐performance liquid chromatography with tandem mass spectrometry
Authors: Vainchtein Liia D. , Rosing Hilde , Thijssen Bas , Schellens Jan H. M. , Beijnen Jos H.
Published: June 2007

A sensitive and specific high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) assay for the quantitative determination of gemcitabine (dFdC) and its metabolite 2′,2′‐difluorodeoxyuridine (dFdU) is presented. A 200‐µL aliquot of human plasma was spiked with a mixture of internal standards, didanosine, lamivudine and fludarabine, and extracted using solid‐phase extraction. Dried extracts were reconstituted in 1 mM ammonium acetate/acetonitrile (97:3, v/v) and 10‐µL volumes were injected onto the HPLC system. Separation was achieved on a 150 × 2.1 mm C18 bonded phase endcapped with polar groups (Synergi Hydro‐RP column) using an eluent composed of 1 mM ammonium acetate (pH 6.8)/acetonitrile (94:6, v/v). Detection was performed by positive ion electrospray ionization followed by MS/MS. The assay quantifies a range from 0.5 to 1000 ng/mL for gemcitabine and from 5 to 10 000 ng/mL for dFdU using 200 µL of human plasma sample. Validation results demonstrate that gemcitabine and dFdU concentrations can be accurately and precisely quantified in human plasma. This assay is used to support clinical pharmacologic studies with gemcitabine. Copyright © 2007 John Wiley & Sons, Ltd.
Pseudo‐downsampled iterative learning control
Authors: Zhang Bin , Wang Danwei , Zhou Keliang , Ye Yongqiang , Wang Yigang
Published: June 2007

In this paper, a simple and effective multirate iterative learning control (ILC), referred as pseudo‐downsampled ILC, is proposed to deal with initial state error. This scheme downsamples the tracking error and input signals collected from the feedback control system before they are used in the ILC learning law. The output of the ILC is interpolated to generate the input for the next cycle. Analysis shows that the exponential decay of the tracking error can be expected and convergence condition can be ensured by downsampling. Other advantages of the proposed pseudo‐downsampled ILC include no need for a filter design and reduction of memory size and computation. Experimental results demonstrate the effectiveness of the proposed scheme. Copyright © 2007 John Wiley & Sons, Ltd.
Assessing non‐inferiority: A combination approach
Authors: Gao Ping , Ware James H.
Published: June 2007

Non‐inferiority designs are growing in importance as a strategy for comparing new drugs with established therapies. Because it is not possible to show that a new drug and the established therapy have identical efficacy profiles, non‐inferiority trials are designed to demonstrate that the new drug is not inferior to an established drug (the ‘control’) relative to a prespecified ‘non‐inferiority margin’. No objective principle guides the choice of the non‐inferiority margin, and controversies about the margin have, in some cases, had important consequences for drug development.

We argue that some of these controversies have arisen because non‐inferiority trials must achieve two objectives. They must demonstrate not only that the new drug is not inferior to the control drug by the non‐inferiority margin, but also that the new drug is superior to placebo. When the second objective is not considered explicitly, it can distort the choice of the non‐inferiority margin. Some methods designed to address both objectives through the choice of the non‐inferiority margin lead to overly stringent non‐inferiority criteria.

We describe an approach to non‐inferiority analysis that combines two tests, a traditional test for non‐inferiority and a test
for superiority based on a synthetic estimate of the effect of the new treatment relative to placebo. The synthetic estimate may be ‘discounted’ to address concerns about assay inconstancy. We discuss power and sample size considerations for the proposed procedure. Copyright © 2007 John Wiley & Sons, Ltd.
Modeling heterogeneity and dependence for analysis of neuronal data
Authors: Wang Xiaofeng , Sun Jiayang , Gustafson Kenneth J. , Yue Guang H.
Published: June 2007

In this paper, we describe two types of neuroscience problems which challenge the typical statistical models assumed for analyzing neuronal data. This offers an opportunity for new modeling and statistical inference. In the first problem, the data are spatial neural counts which are often over‐dispersed and spatially correlated so that a standard Poisson regression model is inadequate. In the second problem, the data are averaged electroencephalograph signals recorded during muscle fatigue, where a time series AR(1) regression model cannot fully capture all the variation and correlation structure in the data. It is shown that an additional parameter has to be included in the modeling of the correlation structure and that the role of the parameter differs from one channel to the other. We propose appropriate generalized models for these data, develop statistical procedures under the generalized models, and apply these procedures to the real data that motivated this paper. The effect of mis‐specification of a correlation structure is also investigated. Copyright © 2007 John Wiley & Sons, Ltd.
Flexible two‐stage design with sample size reassessment for survival trials
Authors: Desseaux K. , Porcher R.
Published: June 2007

Flexible trials with adaptive design modification at interim analyses have been recently proposed as an answer to cope with some limitations of traditional designs for phase III trials. Actually, the sample size and duration of fixed design trials strongly depend on the determination, prior to the study, of key parameters such as the expected treatment effect and the event rates. A misspecification of these parameters may result in an underpowered or overpowered trial. In the flexible framework, the remainder of a design can be modified at an interim analysis, while preserving the initially specified global error rates. In this work, we present a flexible design with sample size re‐evaluation for survival trials and study its properties in practical settings. The results show that, if parameters are initially misspecified, the proposed method allows an improved power control with a reasonable increase in sample size, if any. Practical guidelines concerning the choice of the trial parameters are also given. Copyright © 2007 John Wiley & Sons, Ltd.
The impact of racial diversity on intermediate and long‐term performance: The moderating role of environmental context
Authors: Richard Orlando C. , Murthi B. P. S , Ismail Kiran
Published: June 2007

We conduct a firm‐level, 6‐year longitudinal analysis on the impact that racial diversity in human resources has on financial performance. When considering short‐term performance outcomes, we predict a curvilinear relationship between diversity and performance (i.e., firm productivity). Although we find evidence of a U‐shaped relationship between racial diversity and productivity, the relationship is stronger in service‐oriented relative to manufacturing‐oriented industries and in more stable vs. volatile environments. For longer‐term profitability, we propose and find support for more of a positive linear relationship between diversity and performance (i.e., Tobin's q) than a nonlinear one. This linear effect is stronger and more positive in munificent compared to resource‐scare environments. Thus, we aid in reconciling existing, often contradictory, studies by demonstrating the potential short‐term vs. long‐term impact of racial diversity on performance. We offer implications for future research on diversity considering the current and projected demographic landscape. Copyright © 2007 John Wiley & Sons, Ltd.
Approximate analysis of symmetrical structures consisting of different types of bents
Authors: Georgoussis George K.
Published: June 2007

An approximate analysis is presented for calculating the deflections of individual cantilever bents, under lateral loading, as a sum of deflections of two complementary subsystems: a flexural and a shear–flexure subsystem. The analysis accounts for axial deformations in the vertical members of bents, since it is based on the continuum approach as is used in the coupled wall theory, and is also applicable to other types of cantilever bents used in concrete structures, such as rigid frames and wall frame assemblies. The fact that the deflection equation of a cantilever bent may be decomposed into two components makes possible the development of an approximate method for estimating the deflections of uniform plan‐symmetrical buildings composed of different structural bents. The method provides a rapid estimate of deflections and load distribution in such multi‐bent structures and therefore it is appropriate for preliminary structural design. At this stage, it is desirable for the practising engineer to have a quick estimate of the maximum response, even if the actual sizes of the structural elements are not yet known and only assumptions can be made about the relative stiffnesses of the major structural elements. The proposed analysis, as based on distributed parameter formulations, has the advantage of providing a deep insight into the structural behaviour of high‐rise structures. Its accuracy is evaluated by comparing the approximate results with those obtained by stiffness matrix analyses. Copyright © 2007 John Wiley & Sons, Ltd.
Variability of seismic demands according to different sets of earthquake ground motions
Authors: Han Sang Whan , Kim Eung Soo , Hwang Soo Min
Published: June 2007

It is a challenging task to predict seismic demands for earthquake resistant design, particularly for tall buildings. In current seismic design provisions, seismic demands are expressed as a design base shear of which the key components are linear elastic design response spectra, force reduction factor (‘R factor’), and building weight. For tall buildings, response spectrum analysis or response history analysis is recommended in current design provisions. In recent years, new methods for predicting seismic demands have been developed, such as the capacity spectrum method (CSM) and displacement coefficient method. This study investigates the effect of different earthquake ground motion (EQGM) sets on seismic demands. Key components of the base shear and performance points in the CSM are considered as the seismic demands to be tested. For this purpose three EQGM sets are collected independently at rock sites. This study found that seismic demands can vary significantly according to different EQGM sets even though those sets were obtained at sites with similar soil conditions. This study also attempts to provide a criterion for reducing the variability in seismic demands according to different EQGM sets. Copyright © 2007 John Wiley & Sons, Ltd.
Application of GPS to monitoring of wind‐induced responses of high‐rise buildings
Authors: Park Hyo Seon , Sohn Hong Gyoo , Kim Ill Soo , Park Jae Hwan
Published: June 2007

A new monitoring system using GPS is introduced to measure wind‐induced responses of high‐rise buildings. In this paper, wind‐induced responses of a long‐period structure include relative lateral displacements, acceleration records, and torsional displacements at the top of a building. After comparing responses of a test model measured by GPS with responses obtained by the most commonly used laser displacement meters and accelerometers, the wind‐induced responses of a 66‐story high‐rise building subject to the yellow dust storm were measured by the GPS‐based monitoring system. Based on the field measurement, it is concluded that the complete motion history of a high‐rise building can be monitored by GPS. Copyright © 2007 John Wiley & Sons, Ltd.
Semi‐active control for eccentric structures with MR damper based on hybrid intelligent algorithm
Authors: Li Hong‐Nan , Chang Zhi‐Guo
Published: June 2007

In this paper, an application of the hybrid intelligent control algorithm to semi‐active control of the magnetorheological (MR) damper is presented for engineering structures. The control signal is optimized directly by the µGA approach to obtain the numerical relation between the control signal and the system output. This relation is then stored in the weight value of a trained artificial neural network, which can be available for another structure subjected to other seismic inputs. The results of a numerical example indicate that the semi‐active control of the MR damper based on the hybrid algorithm can efficiently reduce the structural responses induced by an earthquake. Copyright © 2007 John Wiley & Sons, Ltd.
Vibration characteristics of tall buildings braced by shear walls and thin‐walled open‐section structures
Authors: Meftah Sid Ahmed , Tounsi Abdelouahed
Published: June 2007

An analytical method is presented for the three‐dimensional frequency analysis of buildings braced by shear walls and thin‐walled open‐section structures. Owing to the asymmetry of the structure, the centre of gravity and the centre of flexural rigidity of the floor plan do not coincide, and hence the flexural vibration in two mutually perpendicular directions and the warping torsional vibrations are all coupled. Based on the continuum approach and D'Alembert's principle, the governing differential equation of free vibration and its corresponding eigenvalue problem for asymmetric shear walls and thin‐walled open‐section structures are derived. Based on the theory of differential equations, an analytical method of solution is proposed to solve the eigenvalue problem and a general solution is derived for determining the natural frequencies of the structures. Results obtained from the proposed method for the example structure show good agreement with those of finite element analysis. It is also shown that the proposed analysis is efficient and accurate enough to be used both at the concept design stage and for final analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Comparative study of structural material quantities of high‐rise residential buildings
Authors: Kim Sang Bum , Lee Young Hak , Scanlon Andrew
Published: June 2007

A major factor in the selection of the structural system for a high‐rise building is the initial construction cost of candidate structural systems. In Korea, composite steel and concrete construction, and cast‐in‐place concrete flat plate construction are the most commonly used structural systems. However, there is a lack of data related to the relative construction costs of these two structure types. This paper compares material quantities for representative building models up to 80 stories in height using both types of structural system. Based on a typical floor plan, six models are developed and the buildings are designed for gravity and lateral loading. Quantities of materials for each model are calculated and compared. The information presented can be used with appropriate cost data to compare construction costs for the two structural system types. Copyright © 2007 John Wiley & Sons, Ltd.
Upscaling of variational inequalities arising in nonlinear problems with unilateral constraints
Authors: Timofte C.
Published: June 2007

The aim of this paper is to study the asymptotic behavior of the solution of a nonlinear variational inequality in periodically perforated media. The domain is considered to be a fixed bounded open subset of ℝn, in which identical and periodically distributed perforations of size ϵ are made. The asymptotic behavior of the solution of such a problem is governed by an obstacle problem, associated to the homogenization of a periodic heterogeneous and perforated medium.
Optimal control of the free boundary in a two‐phase Stefan problem with flow driven by convection
Authors: Hinze M. , Ziegenbalg S.
Published: June 2007

We present an optimal control approach for the solidification process of a melt in a container. The process is described by a two phase Stefan problem including flow driven by convection and Lorentz forces. The free boundary (interface between the two phases) is modelled as a graph. We control the evolution of the free boundary using the temperature on the container wall and/or the Lorentz forces. The control goal consists in tracking a prescribed evolution of the free boundary. We achieve this goal by minimizing a appropriate cost functional. The resulting minimization problem is solved numerically by a steepest descent method with step size control, where the gradient of the cost functional is expressed in terms of the adjoint variables. Several numerical examples are presented which illustrate the performance of the method.
Non local balance laws in traffic models and crystal growth
Authors: Colombo R.M. , Corli A. , Rosini M.D.
Published: June 2007

This note addresses the well posedness of Temple systems with non local sources. The resulting theorem holds globally in time and without requiring any smallness of the initial data. Its scope comprises models for traffic flow and for crystal growth.
Cytoskeleton as a potential target in the neuropathology of maple syrup urine disease: Insight from animal studies
Authors: Pessoa‐Pureur R. , Wajner M.
Published: June 2007

In this short review we provide evidence that the branched‐chain keto acids accumulating in the neurometabolic disorder maple syrup urine disease disturb rat cerebral cytoskeleton in a developmentally regulated manner. Alterations of protein phosphorylation leading to brain cytoskeletal misregulation and neural cell death caused by these metabolites are associated with energy deprivation, oxidative stress and excitotoxicity that may ultimately disrupt normal cell function and viability.
Cardiac abnormalities in adults with the attenuated form of mucopolysaccharidosis type I
Authors: Soliman O. I. I. , Timmermans R. G. M. , Nemes A. , Vletter W. B. , Wilson J. H. P. , ten Cate F. J. , Geleijnse M. L.
Published: June 2007

Background:

Cardiac involvement in mucopolysaccharidosis type I (MPS I) has been studied primarily in its most severe forms. Cardiac involvement, particularly left ventricular (LV) systolic and diastolic function, in the attenuated form of MPS I is less well known.

Methods:

Cardiac function was prospectively investigated in 9 adult patients with the attenuated form of MPS I. All patients underwent 12‐lead electrocardiography, 24 h Holter monitoring and two‐dimensional echocardiography including tissue Doppler imaging (TDI). Eighteen age‐ and sex‐matched healthy volunteers served as a control group.

Results:

Aortic, mitral and tricuspid valve thickening was seen in, respectively, 5 (56%), 4 (44%) and 2 (22%) patients. Moderate mitral valve stenosis was seen in 1 patient and moderate aortic stenosis in 2 patients. All patients had mild‐to‐moderate aortic and mitral valve regurgitation and 6 patients (67%) had mild‐to‐moderate tricuspid valve regurgitation. Despite normal LV dimensions, ejection fraction and mass index, MPS patients had lower mean systolic mitral annular velocities (6.1±0.6 vs 9.1±1.4 cm/s, p<0.01) compared to normal control subjects. Similarly, mean early diastolic mitral annular velocities were lower in MPS patients (7.8;±0.9 vs 13.3±3.3 cm/s, p<0.01).

Conclusion:

MPS I patients with the attenuated phenotype have not only valvular abnormalities but also LV diastolic and systolic abnormalities.
First ISNS Reference Preparation for Neonatal Screening for thyrotropin, phenylalanine and 17α‐hydroxyprogesterone in blood spots
Authors: Elvers L. H. , Loeber J. G. , Dhondt J.‐L. , Fukushi M. , Hannon W. H. , Torresani T. , Webster D.
Published: June 2007

Background

Neonatal screening for congenital disorders like phenylketonuria (PKU), congenital hypothyroidism (CH) and congenital adrenal hyperplasia (CAH) is generally performed in dried blood spots on filter paper. The analytes of interest for testing for PKU, CH and CAH are phenylalanine, thyrotropin (TSH) and 17α‐hydroxyprogesterone (17OHP), respectively. The International Society for Neonatal Screening (ISNS) decided to prepare a combined reference preparation for the three analytes on filter paper Schleicher & Schuell #903, Whatman BFC180 and Toyo Roshi 545. This ‘First ISNS Reference Preparation for Neonatal Screening for TSH, phenylalanine and 17OHP in blood spots’ (1st ISNS‐RPNS) has been prepared by the RIVM (Bilthoven).

Method

The number of filter paper cards prepared, each with two sets of six blood spot calibrators, was 480, 42 and 69 for Schleicher & Schuell #903, Whatman BFC180 and Toyo Roshi 545, respectively. The volume of blood dispensed was 50 μl. The range of concentrations for TSH was 1–121 mIU/L blood, for phenylalanine 65–865 μmol/L blood and for 17OHP 2.2–302 nmol/L blood.

Results

The linearity of the blood spot calibrators and the homogeneity of the batch (only tested for Schleicher & Schuell) were good. The differences between the three filter papers were small: i.e. the potency of the ISNS‐RPNS on Whatman and Toyo Roshi in terms of Schleicher & Schuell was between 0.98 and 1.09 for the three analytes.

Conclusion

The 1st ISNS‐RPNS for TSH, phenylalanine and 17OHP can be said to be suitable as formal reference preparation and as a source for (re)calibrating kit calibrators.
Hereditary Neuropathy with Liability to Pressure Palsies: Case Report and Discussion
Authors: Grossman Marc J. , Feinberg Joseph , DiCarlo Edward F. , Birchansky Sherri B. , Wolfe Scott W.
Published: June 2007

Hereditary neuropathy with liability to pressure palsies (HNPP) is an uncommon diagnosis that should be considered in patients with multiple compressive neuropathies. We present the case of a woman who presented with bilateral hand numbness and weakness. Electrodiagnostic testing revealed bilateral carpal tunnel syndrome, bilateral ulnar neuropathy at the elbow, left peroneal neuropathy at the fibular head, and a primarily demyelinating generalized sensorimotor neuropathy. Subsequent genetic testing identified a deletion at chromosome 17p11.2 to confirm the diagnosis of HNPP. Treatment of this largely self-limiting disease is controversial, and this patient suffered minimal disability with treatment including splinting and surgical releases.
Primary Biodegradation of Commercial Fatty‐Alcohol Ethoxylate Surfactants: Characteristic Parameters
Authors: Jurado E. , Fernández‐Serrano M. , Núñez‐Olea J. , Lechuga M.
Published: June 2007

This paper concerns the primary biodegradation of different commercial fatty‐alcohol ethoxylate surfactants (FAEs), applying the OECD 301 E test for ready biodegradability. Changes were made both in the carbon‐chain length of the surfactants as well as in the number of units of ethylene oxide (EO) in its molecule. The biodegradation were monitored, analysing the colony‐forming units (CFU) formed during this process. From the biodegradation profiles drawn for the FAEs, parameters characteristic of the biodegradation process were defined: latency time (tL), biodegradability at 50 h of assay (B), half‐life (t1/2), mean biodegradation rate until reaching biodegradability of 85% (VM), and the residual concentration of the surfactant (SR). The analysis of these parameters enabled the establishment of the influence of surfactant concentration and structure during the biodegradation process. The increase in the surfactant concentration lowered the rate of the biodegradation process and the biodegradability of the surfactant in addition to the half‐life and residual concentration of the surfactant. The mean biodegradation rate,VM, for fatty‐alcohol ethoxylates increased with the number of EO units and molecular weight of the surfactant. At low initial test concentrations (less than 25 mg/L), the concentration of the residual surfactant rapidly diminished with biodegradation time. For higher concentrations, after an adaptation period of the microorganisms, the surfactant concentration declined exponentially and the biodegradation rate became far slower for all the surfactants. The parameters characteristic of the growth curves: specific growth‐rate,k, and the yield of biomass production per gram of surfactant,Yap, made possible the quantification and corroboration of the results during the biodegradation process.
Effects of In Ovo Administration of DHEA on Lipid Metabolism and Hepatic Lipogenetic Genes Expression in Broiler Chickens During Embryonic Development
Authors: Zhao Sumei , Ma Haitian , Zou Sixiang , Chen Weihua
Published: June 2007

In order to study the mechanism of DHEA (Dehydroepiandrosterone) in reducing fat in broiler chickens during embryonic development, fertilized eggs were administrated with DHEA before incubation and its effect on lipid metabolism and expression of hepatic lipogenetic genes was investigated. The mRNA levels of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME), apolipoprotein B100 (apoB100) and sterol regulator element binding protein‐1c (SREBP‐1c) were determined using real time quantitative PCR. Samples of livers were collected from the chickens on days 9, 14, and 19 of embryonic development as well as at hatching. Blood samples were extracted on days 14, 19 of incubation and at hatching. The results showed that DHEA decreased the concentration of triacyglycerol in the blood and the content in liver, and the mRNA levels of ACC, FAS, ME, SREBP‐1c and apoB. This suggested that DHEA decreased the expression of hepatic lipogenetic genes and suppressed triglycerols transport, by which it reduced the deposition of fat in adipose tissue in broiler chickens during embryonic development and hatching.
Seasonal Variations of Lipid Content and Composition in Perna viridis
Authors: Li Duo , Zhang Yonghua , Sinclair Andrew J.
Published: June 2007

The total lipid content, composition of main lipid classes, composition of sterols and composition of fatty acids in the main glycerolipids of Perna viridis were analyzed through four seasons using TLC‐FID and GLC. Mussel samples were collected during different seasons between 2003 and 2004 from Shengsi Island, Zhejiang Province, China and stored frozen prior to freeze‐drying and lipid extraction. Ten grams of dried mussel powder of each season were analyzed. Total lipid content ranged from 14.5 g/100 g in spring month to 7.8 g/100 g dried mussel powder in autumn month. The predominant lipid in spring month was triacylglycerol (TAG), however, in the other three seasons the phospholipids (PL) was the main lipid class. The most abundant fatty acid in TAG, PL and phosphatidylcholine (PC) was 16:0, with the summer samples having the highest proportion (24–30% of total fatty acid) and winter the lowest (14–22%). In phosphatidylethanolamine (PE), the spring samples had the highest proportions of 16:0. The predominant polyunsaturated fatty acids (PUFA) were 22:6n‐3 and 20:5n‐3 in TAG, PL, PE and PC (25–40%). The proportions of 22:6n‐3 and 20:5n‐3 were higher in spring than in other seasons in PL and PE. There were nine sterols identified, with cholesterol being the predominant sterol, and other main ones were desmostersol/brassicasterol and 24‐methylenecholesterol. Proportions of other fatty acids in different lipid fractions and the sterol compositions as well also varied seasonally. There were subject to the seasonal variations. Differences in lipid content and composition, fatty acid composition in different lipid fractions may be caused by multiple factors such as lifecycle, sex, variation of plankton in different seasons and temperature, which could influence physiological activities and metabolism.
A differential scanning calorimetry study on the oxidation of C12‐C18 saturated fatty acids and their esters
Authors: Litwinienko G. , Daniluk A. , Kasprzycka‐Guttman T.
Published: June 2007

The autoxidation of lauric, myristic, palmitic, and stearic acids, their ethyl esters, and palmitic and stearic triglycerides was investigated by means of the isothermal and nonisothermal differential scanning calorimetry methods under oxygen flow. The activation energies of oxidation of all investigated compounds were similar (106.0–134.3 kJ/mol) and did not depend on length of the carbon chain. Kinetic parameters of start of the oxidation were similar for each investigated fatty acid and ester. Esterification of carboxyl group did not interfere with the reaction rate. The study showed good agreement between isothermal and nonisothermal data.
Reliability of the bromthymol blue method for color in virgin olive oils
Authors: Moyano M. J. , Melgosa M. , Alba J. , Hita E. , Heredia F. J.
Published: June 2007

The bromthymol blue (BTB) method is currently used for the assessment of color in olive and seed oils by visual comparison with standard solutions. Two BTB scales were prepared with 2 yr difference and compared, and the recent one was used to analyze 502 virgin olive oil samples, obtained by the Abencor® technique reproducing the industrial procedure. The temporal chromatic degradation of the BTB samples after 2 yr [3.93 Commission Internationale de l’Eclairage (CIE) 1976‐(L*a*b*) (CIELAB) units, on the average], as well as the small percentage of virgin olive oils matching the colors of the samples provided by the BTB scales (13.1% with a suprathreshold color tolerance of 1.52 CIELAB units), indicates the limitations of the BTB method. Linear regression models are proposed in order to compute with acceptable accuracy the BTB indices from chromaticparameters. The use of CIELAB for the specification and future studies on color in virgin olive oils is recommended.
Determination of iodine value of palm oil by fourier transform infrared spectroscopy
Authors: Che Man Y. B. , Setiowaty G. , van de Voort F. R.
Published: June 2007

A rapid method for the quantitative determination of iodine value (IV) of palm oil products by FTIR transmission spectroscopy is described. A calibration standard was developed by blending palm stearin and superolein in specific ratios that covered a range of 27.9 to 65.3 IV units. The spectra of these standards was measured in the range between 3050 and 2984 cm−1, corresponding to the absorption band of=C‐H cis stretching vibration. A partial least squares calibration model for the prediction of IV was developed to quantify the IV of palm oil products. A validation approach was used to optimize the calibration with a correlation coefficient of R2=0.9995 and a standard error of prediction of 0.151. This study concludes that the FTIR transmission approach can be used to determine the IV of palm oil products with a total analysis time per sample of less than 2 min for liquid samples.
Synthesis of monoglycerides by glycerolysis of rapeseed oil using immobilized lipase
Authors: Elfman‐Börjesson Inger , Härröd Magnus
Published: June 2007

Reaction conditions for the synthesis of monoglycerides (MG) by enzyme‐catalyzed glycerolysis of rapeseed oil using Lipozyme® IM have been studied. Silica gel was used to adsorb the glycerol to overcome the problems of low glycerol solubility in the organic phase. An experimental design was used where temperature, time, the ratio of silica gel to glycerol (w/w), the water activity (a)w, the isooctane concentration, and the ratio of glycerol to triglycerides (mol/mol) were varied. Response surface methodology was used to evaluate initial reaction rate and yield for the different products. The best yield of MG achieved under the studied conditions was 17.4% (mol fatty acid in substance/total mol fatty acid in mixture) (75°C, 20 h, silica gel/glycerol 2:1, aw=0.17, 48% isooctane, glycerol/triglycerides 6:1). The same conditions yielded 36.8% diglycerides, 13.6% free fatty acids (FFA), and 36.9% triglycerides. This is at the same level as the equilibrium yield. The yield of MG is low compared to the final yield achieved with solid‐phase glycerolysis. However, in solid‐phase glycerolysis the reaction mixture becomes solid, and therefore the solid‐phase process is not suitable for industrial application. The formation of FFA was very fast compared to the synthesis of MG. Equilibrium for FFA was reached within 2 h, and the yield was strongly affected by the aw. Increasing aw greatly increased the formation of FFA. In the aw ratio 0.06–0.3, the yield of FFA increased from 4 to 19% while the yield of MG was nearly unaffected. As FFA is an undesired product, it is important to keep the aw as low as possible.