bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brief cognitive assessment of cancer patients: evaluation of the Mini‐Mental State Examination (MMSE) psychometric properties
Authors: Mystakidou Kyriaki , Tsilika Eleni , Parpa Efi , Galanos Antonis , Vlahos Lambros 
Published: September 2006

AbstractAim: The aim of the present study was to validate the Greek version of the MMSE in advanced‐cancer patients attending a palliative care unit.Methods: The sample consisted of 103 advanced‐cancer patients. The questionnaire was completed at baseline and three days later. Together with the MMSE, the patients also completed the EORTC QLQ‐C30 Cognitive functioning scale, while researchers recorded data on demographic characteristics, disease status and treatment regimen.Results: MMSE had overall Cronbach α 0.890. Validity as performed using known‐group analysis showed good results. MMSE discriminated well between subgroups of patients differing in disease severity as defined by ECOG performance status. Comparison between the MMSE and the EORTC Cognitive functioning scale was statistically significant (p<0.05).Conclusion: These psychometric properties of the Greek version of the MMSE confirm it as a valid and reliable measure when administered to patients with advanced cancer. Copyright © 2006 John Wiley & Sons, Ltd.
Growth of calcium phosphate mineral on carbon nanotube buckypapers
Authors: Tasis D. , Kastanis D. , Galiotis C. , Bouropoulos N. 
Published: September 2006

AbstractCalcium phosphate formation on carbon nanotube buckypapers (CNTB) was studied in vitro. Pristine and citrate‐treated CNTB were immersed in stationary buffered, calcium phosphate supersaturated solutions. The formed precipitate was identified using FTIR spectroscopy as a mixture of both octacalcium phosphate and hydroxyapatite. Scanning electron microscopy analysis revealed that spherulitic calcium phosphate crystals formed in both samples while crystal alignment was observed in the case of citrated treated CNTB. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phonon instability in nanocrystalline silicon carbide
Authors: Cleri F. , Noda T. 
Published: September 2006

AbstractIn recent experiments by a low‐pressure, low‐temperature technique, stable nanotubules of rocksalt SiC were synthetized in massive amounts. Ab‐initio perturbative density‐functional theory calculations in the bulk rocksalt phase provide evidence of drastic phonon softening at a critical pressure of about 2 GPa. To explain the exceptional persistence of the rocksalt structure at ambient conditions we propose that the high pressure induced by interfacial curvature may quench the phonon instability in the nanocrystals down to this minimum threshold, corresponding to the observed nanocrystal size of about 2 nm. Below such pressure the onset of mechanical instability forbids further growth and transformation to ordinary SiC. Nanocrystalline rocksalt SiC is a remarkable example of a material whose unstable, high‐pressure phase is stabilized at ambient conditions upon reducing the grain size in the nanometre range. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman studies of electron–phonon coupling in single walled carbon nanotubes
Authors: Doorn Stephen K. , Goupalov Serguei , Satishkumar B. C. , Shreve Andrew P. , Haroz Erik H. , Bachilo Sergei M. , Weisman R. Bruce 
Published: September 2006

AbstractWe present the results of Raman studies of the chirality dependence of electron–phonon coupling in carbon nanotubes. We demonstrate that a new parameter resulting from a tight binding derivation of the electron–phonon coupling is useful for analysing experimentally‐determined radial breathing mode (RBM) intensities. We also provide a direct comparison of RBM intensities for 6 chiralities obtained with excitation of both the E 11 and E 22 transitions. Analysis of the observed intensity trends in terms of this new parameter demonstrates that the trend to weaker intensities as one excites at resonance with higher lying transitions results from differences in excited‐state decay rates. Finally, we quantitate the magnitude of the matrix elements through modelling of RBM fundamental and overtone Raman excitation profiles using a time‐dependent Raman formalism. Results for 5 chiralities show coupling in general to be weak. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Micromachined pressure sensors for electromechanical characterization of carbon nanotubes
Authors: Stampfer C. , Helbling T. , Jungen A. , Hierold C. 
Published: September 2006

AbstractWe discuss the use of micromachined membrane‐based pressure sensors to investigate electromechanical properties of single‐walled carbon nanotubes. Among the basic transducer concept and the sensor design we mainly focus on the electromechanical transport through nanotubes. Advanced white light interferometer (WLI) based measurement techniques are used to extract the strain on nanotubes adhering to 100‐nm‐thick alumina (Al2O3) membranes. Finally, we present electromechanical measurements on strained single‐walled carbon nanotubes, and the physical nature of the piezoresistive gauge factor in carbon nanotubes and their contrast to classical silicon strain gauges is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polymeric solar cells with oriented and strong transparent carbon nanotube anode
Authors: Ulbricht R. , Jiang X. , Lee S. , Inoue K. , Zhang M. , Fang S. , Baughman R. , Zakhidov A. 
Published: September 2006

AbstractIn this study, an oriented, strong and transparent multiwall carbon nanotube sheet is used as the hole collecting electrode in polymer solar cells with RR‐P3HT as the donor material and PCBM as the acceptor material. An open circuit voltage of 0.49 V, a short circuit current of 5.47 mA/cm2, a fill factor of 0.49, and an efficiency of 1.32% have been obtained. Performance dependence on incident light intensity along with other various investigations are presented. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Double walled carbon nanotube with the smallest inner diameter: a first principles study
Authors: Kürti J. , Zólyomi V. , Yang S. , Kertesz M. 
Published: September 2006

AbstractThe smallest possible inner tube diameter in a double walled carbon nanotube is the zero diameter inner tube, in other words, an infinite linear carbon chain. In this work, we present a first principles study of the vibrational properties of the infinite carbon chain, employing a novel linear/exponential scaling scheme based on the intrinsic behavior of the long range force constant couplings in quasi one‐dimensional chains. The longitudinal optical Raman active frequency is predicted at 1870–1877 cm–1, in contrast to the widely accepted values in the 2000–2200 cm–1 range. Our results provide further evidence for the assignment of the characteristic Raman peaks near 1850 cm–1 of the recently discovered long linear carbon chains encapsulated inside multi‐walled or double walled carbon nanotubes. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Encapsulating C59N azafullerenes inside single‐wall carbon nanotubes
Authors: Simon F. , Kuzmany H. , Fülöp F. , Jánossy A. , Bernardi J. , Hauke F. , Hirsch A. 
Published: September 2006

AbstractFilling of single‐wall carbon nanotubes with C59N azafullerene derivatives is reported from toluene solvent at ambient temperature. The filling is characterized by high resolution transmission electron microscopy and Raman spectroscopy. The tube–azafullerene interaction is similar to the tube–C60 interaction. The encapsulated C59N monomer radical is observed using electron spin resonance spectroscopy after vacuum annealing of the azafullerene derivatives. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of phenyl rings in liquid crystal molecules on SWCNTs studied by Raman spectroscopy
Authors: Scalia Giusy , Lagerwall Jan P. F. , Haluska Miroslav , Dettlaff‐Weglikowska Ursula , Giesselmann Frank , Roth Siegmar 
Published: September 2006

AbstractCarbon nanotubes can be aligned by dispersing them in a liquid crystalline matrix. To control and optimize the obtained alignment it is important to understand the interactions between the molecules of the liquid crystal host phase and the carbon nanotubes. To this end we have carried out resonant Raman spectroscopy investigations of dispersions of single‐wall carbon nanotubes (SWCNTs) in a liquid crystal compound comprising molecules with a biphenyl rigid core structure. We detect a distinct wavenumber shift of the radial breathing modes, confirming that the carbon nanotubes interact with the surrounding liquid crystal molecules, most likely through aromatic interactions (π‐stacking). The interactions between liquid crystal host and nanotube guests are also evident from a polarizing microscopy study of the liquid crystal–isotropic phase transition in the proximity of bundles of nanotubes. The ordered liquid crystal phase is stable up to higher temperatures around the bundles than in areas without visible signs of CNTs. Conversely, the transition from the disordered isotropic phase to the liquid crystal phase on cooling always nucleates at the carbon nanotube bundles. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of liquid chromatography/ion trap mass spectrometry to the characterization of the related substances of clarithromycin
Authors: Leonard Stefanie , Ferraro Monica , Adams Erwin , Hoogmartens Jos , Schepdael Ann Van 
Published: September 2006

AbstractA selective reversed‐phase liquid chromatography/mass spectrometry (LC/MSn) method was developed for the characterization of components of the semi‐synthetic macrolide clarithromycin. Mass spectral data were acquired online on a LCQ ion trap mass spectrometer equipped with an electrospray ionization source operated in the positive ion mode. One unknown compound was structurally elucidated and two other unknowns were characterized using the MS/MS and MSn collision‐induced dissociation spectra of reference substances as interpretative templates, combined with knowledge of the nature of functional group fragmentation behaviour. Given the importance attached to the identification of impurities of unknown identity in pharmaceutical substances, this study is useful for companies producing clarithromycin. Copyright © 2006 John Wiley & Sons, Ltd.
Lateral resolution of secondary ion mass spectrometry–results of an inter‐laboratory comparison
Authors: Senoner M. , Unger W. E. S. 
Published: September 2006

AbstractRecently, BAM organised an inter‐laboratory comparison focussed on lateral resolution and accuracy of sub‐micron length measurements by secondary ion mass spectrometry (SIMS). Results were submitted by 16 laboratories from 10 countries. The task was to analyse a cross‐sectioned semiconductor multilayer stack. The resulting strip pattern in the surface of the sample shows narrow strips, step transitions and gratings of different periods. Imaging analysis of this pattern enables the determination of relevant parameters related to the lateral resolution: (i) The width (FWHM) of the primary ion beam, (ii) the distance between 16% and 84% intensity points in a profile across the image of a step transition and (iii) the modulation of intensity in the images of gratings with different periods. The parameter's data reported by the participants vary in a wide range. A strong variation in the data of primary ion beam width was observed for results measured with the same type of instrument. The distance between two narrow strips was measured with high accuracy. Twelve of sixteen of the submitted values are within the limits of uncertainty of the reference value 964 ± 35 nm. This result shows that the calibration of the length scale of the SIMS instruments is already rather precise in most of the participating laboratories. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of a passivation layer comprising MgOSiO2 and ZrO2
Authors: Kim Na‐Rae , Lee Yang‐Doo , Paek Kyeong‐Kap , Lee Joo‐Won , Kim Jai‐Kyeong , Hwang Sung‐Woo , Ju Byeong‐Kwon 
Published: September 2006

AbstractThin films with magnesium oxide (MgO) and silicon oxide (SiO2) compounds mixed at various mixture ratios were deposited on flexible polyether sulfone (PES) substrates by an e‐beam evaporator to investigate their potential for transparent barrier applications. In this study, as the MgO fraction increased, thin films comprising MgO and SiO2 compounds became more amorphous, and their surface morphologies became smoother and denser. In addition, zirconium oxide (ZrO2) was added to the above‐mentioned compound mixtures, and the properties of the compound mixture comprising MgSiZrO were then measured. ZrO2 made the thin mixture films more amorphous, and made the surface morphology denser and more uniform. Whole thin films of 250 ± 30 nm in thickness were formed, and their water vapor transmission rates (WVTRs) decreased rapidly. The best WVTR was obtained by depositing thin films of MgSiZrO compound among the whole thin films. The WVTRs of the PES substrate in the bare state decreased from 47 to 0.8 g m−2 day−1. This MgSiZrO compound was deposited on polyethylene terephtalate (PET) substrates again to confirm the availability of the compound mixture. Thin films on the PET substrates decreased the WVTRs remarkably from 2.96 to 0.01 g m−2 day−1. These results were similar to those of thin films on PES substrates. As the thin mixture films became more amorphous and surface morphology denser and more uniform, the WVTRs decreased. Therefore, the thin mixture films became more suitable for flexible organic light emitting displays (OLEDs) as transparent passivation layers against moisture in air. Copyright © 2006 John Wiley & Sons, Ltd.
Improved sputter depth resolution in Auger composition‐depth profiling of polycrystalline thin film systems using single grain depth profiling
Authors: Scheithauer U. 
Published: September 2006

AbstractToday in‐depth profiling of microelectronics thin film systems is one of the important applications of Auger electron spectroscopy. It is used to monitor the elemental in‐depth composition after different manufacturing processes to control the quality of these processes. For instance, the layer interdiffusion and reactions with various process gases are analyzed. In addition, interface contaminations have to be controlled, because they strongly influence the properties of the whole thin film system.For polycrystalline layers, the depth resolution of sputter depth profiling is limited by the sputter yield differences attributed to grains having different crystalline orientations relative to the incoming ion beam. If depth profiling can be performed on single grains only, the poor depth resolution caused by these sputter yield differences can be avoided. Unfortunately, the approach works only on a few samples because single grains must be identified and have to have grain sizes that are in the dimensions of the layer thickness. Using methods of in situ sample preparation, however, allows application of single grain depth profiling to an extended range of thin film systems. Copyright © 2006 John Wiley & Sons, Ltd.
Seasonal confounding in air pollution and health time‐series studies: effect on air pollution effect estimates
Authors: Touloumi G. , Samoli E. , Pipikou M. , Le Tertre A. , Atkinson R. , Katsouyanni K. 
Published: September 2006

AbstractA major statistical challenge in air pollution and health time‐series studies is to adequately control for confounding effects of time‐varying covariates. Daily health outcome counts are most commonly analysed by Poisson regression models, adjusted for overdispersion, with air pollution levels included as a linear predictor and smooth functions for calendar time and weather variables to adjust for time‐varying confounders. Various smoothers have been used so far, but the optimal strategy for choosing smoothers and their degree of smoothing remains controversial. In this work, we evaluate the performance of various smoothers with different criteria for choosing the degree of smoothing in terms of bias and efficiency of the air pollution effect estimate in a simulation study. The evaluated approaches were also applied to real mortality data from 22 European cities. The simulation study imitated a multi‐city study. Data were generated from a fully parametric model. Model selection methods which optimize prediction may lead to increased biases in the air pollution effect estimate. Minimization of the absolute value of the sum of the partial autocorrelation function of the model's residuals (PACF), as a criterion to choose the degree of smoothness, gave the smallest biases. The penalized splines (PS) method with a large number of effective dfs (e.g. 8–12 per year) could be used as the basic, relatively conservative, analysis whereas the PS and natural splines in combination with PACF could be applied to provide a reasonable range of the effect estimate. Copyright © 2006 John Wiley & Sons, Ltd.
Measuring the complexity of class diagrams in reverse engineering
Authors: Sheldon Frederick T. , Chung Hong 
Published: September 2006

AbstractComplexity metrics for object‐oriented systems are plentiful. Numerous studies have been undertaken to establish valid and meaningful measures of maintainability as they relate to the static structural characteristics of software. In general, these studies have lacked the empirical validation of their meaning and/or have only succeeded in evaluating partial aspects of the system. In this study we have determined, through limited empirical means, a practical and holistic view by analyzing and comparing the structural characteristics of UML class diagrams as those characteristics relate to or impact maintainability. Class diagrams are composed of three kinds of relation, association, generalization, and aggregation, which make their overall structure difficult to understand. We propose combining these three relations in such a way that enables a comprehensive measure of complexity. Theoretically, this measure is applicable among different class diagrams (including different domains, platforms or systems) to the extent that the measure is widely comparative and context free. Further, this property does not preclude comparison within a specific class diagram (or family) and is therefore very useful in evaluating a given class diagram's strengths and weaknesses. We are reporting empirical results that provide a small measure of validity to enable an objective appraisal of both complexity and maintainability without equating the two. Therefore, to evaluate our structural complexity metric, we determined the level of understandability of the system by measuring the time needed to reverse engineer source code into class diagrams including the number of errors produced while creating the diagram. The number of errors produced offers one indicator of maintainability. The results, as compared with other complexity metrics, indicate that our metric shows promise especially if proven to be scalable. Copyright © 2006 John Wiley & Sons, Ltd.
Degeneracy in Candecomp/Parafac Explained for p × p × 2 Arrays of Rank p + 1 or Higher
Authors: Stegeman Alwin 
Published: September 2006

AbstractThe Candecomp/Parafac (CP) model decomposes a three-way array into a prespecified number R of rank-1 arrays and a residual array, in which the sum of squares of the residual array is minimized. The practical use of CP is sometimes complicated by the occurrence of so-called degenerate solutions, in which some components are highly correlated in all three modes and the elements of these components become arbitrarily large. We consider the real-valued CP model in which p × p × 2 arrays of rank p + 1 or higher are decomposed into p rank-1 arrays and a residual array. It is shown that the CP objective function does not have a minimum in these cases, but an infimum. Moreover, any sequence of CP approximations, of which the objective value approaches the infimum, will become degenerate. This result extends Ten Berge, Kiers, & De Leeuw (1988), who consider a particular 2 × 2 × 2 array of rank 3.
Sign changing bubble tower solutions in a slightly subcritical semilinear Dirichlet problem
Authors: Weth Tobias , Pistoia Angela 
Published: September 2006

We consider the problem

−\mathrm{\Delta }u = |u|^{p−1−ɛ}u

in

Ω

,

u = 0

on

∂Ω

, where

Ω

is a bounded smooth domain in

\mathbb{R}^{N}

symmetric with respect to

x_{1},…,x_{N}

, which contains the origin,

N⩾3

,

p = \frac{N + 2}{N−2}

and

ɛ

is a positive parameter. As

ɛ

goes to zero, we construct sign changing solutions with multiple blow up at the origin. These solutions have, as

ɛ

goes to zero, more and more annular-shaped nodal domains.

Résumé

Nous considérons le problème

−\mathrm{\Delta }u = |u|^{p−1−ɛ}u

dans

Ω

,

u = 0

sur

∂Ω

, où

Ω

est un domaine borné de

\mathbb{R}^{N}

symétrique par rapport à

x_{1},…,x_{N}

qui contient l'origine,

N⩾3

,

p = \frac{N + 2}{N−2}

et

ɛ

est un paramètre positif. Quand

ɛ\rightarrow 0

, nous construisons des solutions changeant de signe qui ressemblent à une superposition de transitoires centrées dans l'origine. Ces solutions admettent, quand

ɛ\rightarrow 0

, de plus en plus de domaines nodeaux ressemblant à un anneau.
Prescribing scalar curvature on \( S^{3} \)
Authors: Schneider Matthias 
Published: September 2006

We give existence results for solutions of the prescribed scalar curvature equation on

S^{3}

, when the curvature function is a positive Morse function and satisfies an index-count condition.

Résumé

Nous démontrons l'existence de solutions de l'équation courbure scalaire sur

S^{3}

, quand la courbure scalaire est une fonction de Morse positive satisfaisant à une condition d'indice.
Strong instability of solitary waves for nonlinear Klein–Gordon equations and generalized Boussinesq equations
Authors: Liu Yue , Ohta Masahito , Todorova Grozdena 
Published: September 2006

We study here instability problems of standing waves for the nonlinear Klein–Gordon equations and solitary waves for the generalized Boussinesq equations. It is shown that those special wave solutions may be strongly unstable by blowup in finite time, depending on the range of the wave's frequency or the wave's speed of propagation and on the nonlinearity.

Résumé
On étudie des problèmes d'instabilité des ondes stationnaires pour des équations de Klein–Gordon non linéaires et des ondes solitaires pour des équations généralisées de Boussinesq. On établit que ces solutions d'ondes spéciales peuvent être fortement instables par explosion en temps fini, selon le rang de la fréquence des ondes ou la vitesse de propagation des ondes et la non-linéarité.