bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi‐actuated functionally graded piezoelectric micro‐tools design: A multiphysics topology optimization approach
Authors: Carbonari Ronny C. , Silva Emílio C. N. , Paulino Glaucio H.
Published: September 2008

Micro‐tools offer significant promise in a wide range of applications such as cell manipulation, micro‐surgery, and micro/nanotechnology processes. Such special micro‐tools consist of multi‐flexible structures actuated by two or more piezoceramic devices that must generate output displacements and forces at different specified points of the domain and at different directions. The micro‐tool structure acts as a mechanical transformer by amplifying and changing the direction of the piezoceramics output displacements. The design of these micro‐tools involves minimization of the coupling among movements generated by various piezoceramics.To obtain enhanced micro‐tool performance,the concept of multifunctional and functionally graded materials is extended by tailoring elastic and piezoelectric properties of the piezoceramics while simultaneously optimizing the multi‐flexible structural configuration using multiphysics topology optimization. The design process considers the influence of piezoceramic property gradation and also its polarization sign. The method is implemented considering continuum material distribution with special interpolation of fictitious densities in the design domain. As examples, designs of a single piezoactuator, anXYnano‐positioner actuated by two graded piezoceramics, and a micro‐gripper actuated by three graded piezoceramics are considered. The results show that material gradation plays an important role to improve actuator performance, which may also lead to optimal displacements and coupling ratios with reduced amount of piezoelectric material. The present examples are limited to two‐dimensional models because many of the applications for such micro‐tools are planar devices. Copyright © 2008 John Wiley & Sons, Ltd.
Least‐squares mixed finite elements for small strain elasto‐viscoplasticity
Authors: Schwarz A. , Schröder J. , Starke G.
Published: September 2008

The main aim of this contribution is to provide a mixed finite element for small strain elasto‐viscoplastic material behavior based on the least‐squares method. The L2‐norm minimization of the residuals of the given first‐order system of differential equations leads to a two‐field functional with displacements and stresses as process variables. For the continuous approximation of the stresses, lowest‐order Raviart–Thomas elements are used, whereas for the displacements, standard conforming elements are employed. It is shown that the non‐linear least‐squares functional provides an a posteriori error estimator, which establishes ellipticity of the proposed variational approach. Further on, details about the implementation of the least‐squares mixed finite elements are given and some numerical examples are presented. Copyright © 2008 John Wiley & Sons, Ltd.
Inhaled insulin treatment for type 1 diabetes, following major skin loss from necrotising fasciitis
Authors: Maguire D , Bodansky HJ
Published: September 2008

A 21‐year‐old female with poorly controlled type 1 diabetes was admitted with diabetic ketoacidosis and a groin abscess which was incised and drained. She developed necrotising fasciitis affecting the lower abdomen and upper thighs, which required extensive debridement. Subsequent skin grafts were successful; however, injection sites were now limited. She was commenced on inhaled insulin with meals and glargine insulin once daily.

This is an unusual indication for inhaled insulin. This case demonstrates the importance of alternative routes of administration of insulin when intensive subcutaneous therapy is not possible. Copyright © 2008 John Wiley & Sons.
Suboptimal glycaemic control in primary care: is the need for intensification of therapy recognised?
Authors: Rosindale S , Lockett H , Bromige R , Darby A , Dyer R
Published: September 2008

The United Kingdom Prospective Diabetes Study demonstrated the importance of good glycaemic control in patients with type 2 diabetes. Despite this knowledge, half of the population with diabetes have an HbA1c above 8%.

Five general practices in Torbay identified all patients with type 2 diabetes and suboptimal glycaemic control (HbA1c >7.5%) who were not on insulin. A retrospective review of the general practice records of patients was performed. Patients were categorised into: need to consider insulin; need to increase oral agents; treatment has recently been appropriately increased; patient plans to commence insulin; insulin considered inappropriate or patient declined insulin; patient under a secondary care diabetes team; patient diagnosed with diabetes within the last year.

In all, 376 patients with an HbA1c >7.5% were identified. Of these, 118 patients (31.4%) had appropriately increased their oral medication. Only 21 had discussed insulin initiation but an additional 74 were classified as needing to consider insulin therapy. Twenty‐three percent required an increase in their oral hypoglycaemic medication. Insulin was declined by the patient or thought inappropriate in 49 cases. There were 17 new diagnoses and only eight under secondary care.

In conclusion, 43% of patients with type 2 diabetes and HbA1c >7.5% required an increase in oral medication or consideration for insulin. This need had not been recognised in the majority of cases. We believe that closer liaison between primary care and specialist diabetes teams is required. Copyright © 2008 John Wiley & Sons.
Quality of life and impact of continuous subcutaneous insulin infusion for children and their parents
Authors: Barnard KD , Speight J , Skinner T C
Published: September 2008

This study aimed to identify key components of quality of life (QoL) and assess the impact of insulin pump therapy on children/adolescents with type 1 diabetes and their parents.

The Schedule for the Evaluation of Individualised Quality of Life (SEIQoL) interview was adapted to be (1) insulin pump‐specific, (2) suitable for children and their parents, and (3) suitable for telephone administration. Interviews were conducted separately with children/parents to elicit the five most important aspects of life for their QoL and to identify the impact of insulin pump therapy on those domains.

All children (and parents) who were registered on the Roche Diagnostics insulin pump user customer database were invited to participate.

Participants included 15 children/adolescents (mean age 12.07±2.71 years; range 9–17 years) and 17 parents. Mean diabetes duration was 6.67±2.42 years (range: 2–12 years). There was no significant difference in length of interview between parents and children (p = 0.281). All parents reported the impact of their children's insulin pump therapy on their own overall QoL as positive (47.1% very much better, 35.3% much better, 17.6% better). Fourteen children/adolescents answered this question and all responses were positive (28.6% very much better, 57.1% much better, 14.3% better). For parents, the most frequently reported aspects of life important for their QoL were ‘health’ and ‘family’ whilst children most frequently reported ‘family’, ‘friends’ and ‘school’.

In conclusion, all children and their parents reported the impact of pump therapy on their QoL to have been positive. Furthermore, parents perceive many benefits of importance for their own QoL from their child(ren) using insulin pump therapy. Copyright © 2008 John Wiley & Sons.
Synthesis and characterization of hybrid fluoro‐emulsion based on silica/copolymer composite particles
Authors: Qu Ailan , Wen Xiufang , Pi Pihui , Cheng Jiang , Yang Zhuoru
Published: September 2008

BACKGROUND: To create a hydrophobic surface, a commonly used two‐step process is the formation of a rough surface and its subsequent modification with materials of low surface energy. Here, a new method for making a hydrophobic surface is proposed using emulsion copolymerization with a low‐surface‐energy fluoropolymer in the presence of a high percentage of silica particles creating a well‐spread roughness.

RESULTS: Irregular core–shell structural composite particles such as of snowman shape and sandwich shape were obtained and characterized. The hydrophobicity and chemical structure of the hybrid film were investigated. It was found that strong inter‐ and intramolecular chemical bonding in the composite film may improve the properties of the hybrid film. Enrichment of fluorine on the film surface and well‐distributed roughness due to the silica particles covered by the fluoropolymer contribute to the increased hydrophobicity of the film. The water contact angle on the film increased from 106 ± 2° to 135 ± 2°.

CONCLUSION: The stable core–shell hybrid latex synthesized in this work will be of use in preparing high‐performance hydrophobic aqueous coatings. Copyright © 2008 Society of Chemical Industry
Determination of protein and RNA expression levels of common housekeeping genes in a mouse model of neurodegeneration
Authors: Calvo Ana C. , Moreno‐Igoa María , Manzano Raquel , Ordovás Laura , Yagüe Gema , Oliván Sara , Muñoz María J. , Zaragoza Pilar , Osta Rosario
Published: September 2008

The choice of housekeeping proteins or genes for internal standards should be made carefully, taking into account the cell and tissue type, the experimental conditions, and the healthy/disease state(s) under consideration. Furthermore, as the correlation between transcriptional and translational levels of commonly used housekeeping genes is often discussed, this study shed light on the transcriptional levels of β‐actin and glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and the translational levels of β‐actin, GAPDH, and β‐tubulin in an amyotrophic lateral sclerosis mouse model.
A novel method for isolation of membrane proteins: A baculovirus surface display system
Authors: Zhang Yaozhou , Lv Zhengbing , Chen Jian , Chen Qin , Quan Yanping , Kong Lingyin , Zhang Haihua , Li Si , Zheng Qingliang , Chen Jianqing , Nie Zuoming , Wang Jiang , Jin Yongfeng , Wu Xiangfu
Published: September 2008

We have developed a novel baculovirus surface display (BVSD) system for the isolation of membrane proteins. We expressed a reporter gene that encoded hemagglutinin gene fused in frame with the signal peptide and transmembrane domain of the baculovirus gp64 protein, which is displayed on the surface of BmNPV virions. The expression of this fusion protein on the virion envelope allowed us to develop two methods for isolating membrane proteins. In the first method, we isolated proteins directly from the envelope of budding BmNPV virions. In the second method, we isolated proteins from cellular membranes that had disintegrated due to viral egress. We isolated 6756 proteins. Of these, 1883 have sequence similarities to membrane proteins and 1550 proteins are homologous to known membrane proteins. This study indicates that membrane proteins can be effectively isolated using our BVSD system. Using an analogous method, membrane proteins can be isolated from other eukaryotic organisms, including human beings, by employing a host cell‐specific budding virus.
Proteomics Data Collection – 3rd ProDaC Workshop April 22nd 2008, Toledo, Spain
Authors: Eisenacher Martin , Hardt Tanja , Martens Lennart , Häkkinen Jari , Apweiler Rolf , Hamacher Michael , Meyer Helmut E. , Stephan Christian
Published: September 2008

The “Coordination Action” ProDaC (Proteomics Data Collection) – funded by the EU within the 6th framework programme – was created to support the dissemination, utilization and publication of proteomics data. Within this international consortium, standards are developed and maintained to support extensive data collection by the proteomics community. An important part of ProDaC are workshops organized on a regular basis (two per year) to allow discussions and communication between the ProDaC partners and to report on the progress of the project. The kick‐off meeting took place in October 2006 in Long Beach, CA, USA. The 1st ProDaC workshop was held in Lyon, France (April 2007) and the 2nd in Seoul, Korea in October 2007. ProDaC organized the 3rd ProDaC workshop at the Beatriz Hotel, Toledo, on 22nd April, 2008, directly before the HUPO ‐ PSI spring meeting (Human Proteome Organisation ‐ Proteomics Standards Initiative). The work package coordinators presented talks about the progress achieved during the past six months. Additionally four external speakers presented their work on data conversion and data repositories. The concluding discussion session was chaired by the Journal's representative.
1st Irish Proteomics Workshop April 17th 2008, University College Dublin, Conway Institute, Dublin, Ireland
Authors: McManus Ciara A. , English Jane A.
Published: September 2008

The workshop assembled an excellent collection of speakers from across Ireland and beyond who presented many interesting and diverse topical issues. Various proteomic applications were discussed throughout the day ranging from 2‐DE and 2‐D DIGE, to GeLC‐MS/MS, high density Protein and Antibody Arrays, with a particular focus on the importance of quantitative mass spectrometry in proteomics.
High frequency of prostate antigen‐directed T cells in cancer patients compared to healthy age‐matched individuals
Authors: Forsberg Ole , Carlsson Björn , Malmström Per‐Uno , Ullenhag Gustav , Tötterman Thomas H. , Essand Magnus
Published: September 2008

BACKGROUND

In order to obtain a sustained cytotoxic T lymphocyte (CTL) response against cancer cells it is preferable to have CTLs directed against multiple peptide epitopes from numerous tumor‐associated antigens.

METHODS

We used a Flow Cytometry‐based interferon (IFN)‐γ secretion assay with peptide‐pulsed C1R‐A2 as antigen‐presenting cells to analyze whether CD8+ T cells directed against any of 24 HLA‐A*0201‐binding peptides from 15 prostate‐associated proteins can be found in the peripheral blood of patients with localized prostate cancer. We also investigated whether multiple prostate antigen‐specific CD8+ T cells can be generated simultaneously, from a naïve T cell repertoire. In that case, dendritic cells (DCs) from peripheral blood of healthy donors were divided in six portions and separately pulsed with six peptides. The peptide‐pulsed DCs were then pooled and used to stimulate autologous T cells. The T cells were re‐stimulated with peptide‐pulsed monocytes.

RESULTS

We found prostate antigen‐restricted CD8+ T cells in the peripheral blood in 48 out of 184 (26.1%) analyzed samples from 25 cancer patients. This is significantly higher than 17 out of 214 analyzed samples (7.9%) from 10 healthy age‐matched male individuals (P = 0.0249). In the cases when antigen‐specific T cells could not be detected, we were able to generate IFN‐γ‐producing CD8+ T cells specific for up to three prostate antigens simultaneously from a naïve T cell repertoire.

CONCLUSIONS

CD8+ T cells directed against prostate antigen peptides can be found in, or generated from, peripheral blood. This indicates that such T cells could be expanded ex vivo for adoptive transfer to prostate cancer patients. Prostate 69: 70–81, 2009. © 2008 Wiley–Liss, Inc.
The study of ESD induced defects in smart power ESD protection circuits using low frequency noise measurements
Authors: Hadzi‐Vukovic J. , Jevtic M. , Glavanovics M. , Rothleitner H.
Published: September 2008

To investigate the reliability of ESD protection in smart power integrated circuits the ESD experiments are performed and degradation is analyzed by low frequency noise measurements. Combining the noise results with further failure analysis analytical methods we have examined a location and the nature of defects. Special attention was dedicated to analysis of latent defects. The possibility to apply noise as reliability indicator for repetitive testing and for use in high volume production are also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low energy loss rf circuits on nanostructured porous silicon layers
Authors: Porcher A. , Remaki B. , Malhaire C. , Barbier D.
Published: September 2008

We present a work dealing with the study of thick porous silicon (PS) as insulating substrate for radio frequency (rf) circuits. Planar LC resonant circuits of 2 mm x 2 mm were designed on 100 µm thick PS layers for uses in 10 MHz to 1 GHz frequency range. The influence of PS electrical conductivity on the energy loss is determined using an original method based on experimental data combined with numerical simulations. We have clearly shown the increase of PS conductivity with the frequency due to hopping transport mechanisms in disordered materials. The contribution of the porous substrate to the energy loss is dominant for conductivities higher than 10–3 S/cm. Finally, the insertion of a SiO2 layer between an oxidized porous substrate and the integrated micro‐coil is suggested to optimize the quality factor of integrated rf resonnant circuits. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependent EXAFS of InN
Authors: Katsikini M. , Pinakidou F. , Paloura E. C. , Komninou Ph. , Georgakilas A. , Welter E.
Published: September 2008

The effect of temperature on the bonding environment of indium in an InN epilayer is studied using X‐ray absorption fine structure (EXAFS) spectroscopy. Shell‐by‐shell fitting of the EXAFS spectra reveals that, in the temperature range 80‐245 K, the change in the nearest neighbour distances is smaller than the uncertainty of the measurement. The Debye–Waller factor of the second neighbouring shell (In–In pair) shows strong temperature dependence. Fitting using the Einstein model yields an Einstein temperature equal to 193 K ± 5%. An alternative way of extracting information on the vibrational properties of the lattice is the simulation using the equation of motion method for the determination of the Debye–Waller factors. The used values of 120 N/m and 50 N/m of the force constants for In–N and In–In bond stretching, respectively, simulate satisfactory the spectra measured at five different temperatures in the range 80– 245 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel effects in finite‐length silicon nanowires
Authors: Zdetsis A. D. , Koukaras E. N. , Garoufalis C. S.
Published: September 2008

By considering silicon nanowires in real space, we have shown by ab initio theoretical calculations that unstable nanowires bend under relaxation. These nanowires usually incorporate in their surface silicon dihydrides parallel to the nanowires axis. On the other hand, nanowires without such parallel dihydrides remain straight and are characterized by increased stability or “magicity”. Reconstructed nanowires have analogous properties but they are characterized by much higher stability. This bending of the nanowires cannot be accounted for by the usual k‐space models which use a one‐dimensional periodic arrangement of the simulation cell. Our theoretical models are based on STM images and schematic views from recent experimental results [Science 229, 1874, (2003)]. Our results are in full accord with these experimental data and interpretations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deterministic simulation of transport in MOSFETs by coupling Wigner, Poisson and Schrödinger equations
Authors: Kefi‐Ferhane J. , Poncet A.
Published: September 2008

In this paper, we present a new simulation approach for quantum transport in short and thin MOSFET channels which is based on a deterministic resolution of 1D Wigner Transport Equation and its couplings with 2D Poisson and 1D Schrödinger equations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microstructure and defect investigations of the layered manganites La2–2xCa1+2xMn2O7 (x = 0.6, 0.8 and 0.9) by HREM
Authors: Wang Yumei , Yu Richeng
Published: September 2008

The microstructure and defects of the n = 2 Ruddlesden–Popper manganites La2–2x Ca1+2x Mn2O7 (x = 0.6, 0.8 and 0.9) were investigated by electron diffraction and high‐resolution transmission electron microscopy. Besides the predominant n = 2 layered structure in the examined compounds, intergrowths with different number of the perovskite‐like layers were observed. Intergrowth of n = 1 (K2NiF4‐type) was observed only in x = 0.9 sample. Intergrowths with n ≥ 5, essential perovskite microdomains or inclusions, were seen in the x = 0.8 and 0.6 samples. The type of defects in x = 0.8 sample is much richer than that in x = 0.6 and 0.9 samples and two rare types were observed and analyzed. Some of edge dislocations in the x = 0.6 specimen were presented. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and optical studies of Eu3+ ions in alkali borate glasses
Authors: Marimuthu K. , Surendra Babu S. , Muralidharan G. , Arumugam S. , Jayasankar C. K.
Published: September 2008

Europium‐doped borate‐based glasses (Eu3+:MBE (M = Na, K and Na + K)) have been prepared by a melt quenching technique and characterized optically. FTIR spectra and XRD patterns were used to analyze the glass structure. The spectroscopic properties such as optical absorption and photoluminescence spectra and decay time measurements for the 5D0 level of Eu3+ ions were obtained. A strong red fluorescence is observed from the 5D0 level of Eu3+ ions in these glasses. Judd–Ofelt (JO) parameters have been evaluated from the luminescence intensity ratios of 5D0 → 7FJ (J = 2 and 4) to 5D0 → 7F1 transitions. These parameters have been used to derive radiative properties such as transition probabilities, branching ratios, radiative lifetimes and peak stimulated emission cross sections for the 5D0 → 7FJ transitions. The relative luminescence intensity ratio (R) of 5D0 → 7F2 to 5D0 → 7F1 transitions has been evaluated to estimate the local site symmetry around the Eu3+ ions. Relatively higher values of R and the JO parameter Ω2 for the Eu3+:MBE glasses suggest a lower symmetry for Eu3+ ions and a higher Eu–O covalence. Decay curves of the 5D0 level of Eu3+ ions have been measured by monitoring the 5D0 → 7FJ transition (at around 612 nm) at room temperature. The experimental lifetime of the 5D0 level in these glasses is found to be lower than Eu3+‐doped phosphate glasses and comparable to or higher than Eu3+‐doped niobium phosphate or tellurite glasses. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical investigations of spin‐Hamiltonian parameters for Ru3+ ions in rutile (TiO2) crystal
Authors: He Lv , Zheng Wen‐Chen
Published: September 2008

In this paper, we present two diagonalization of energy matrix methods (DEM‐I and DEM‐II) to calculate the spin‐Hamiltonian (SH) parameters of the low‐spin d5 configuration (with the ground state 2T2 and spin S = 1/2) in rhombic symmetry. The x ‐ and y‐axes in which SH parameters are expressed are taken along the bisectors of the angles between metal‐ligand bonds in crystals e.g., rutile‐type crystals. In DEM‐I, the Hamiltonian related to energy matrix within the 2T2 term does not contain the Zeeman interaction and hyperfine interaction, whereas in DEM‐II, it does. Based on the two methods, the SH parameters (g factors gi, hyperfine structure constants 99Ai and 101Ai, where i = x, y, z) of Ru3+ (4d5) ions in TiO2 are calculated. The results from both methods coincide and are also in reasonable agreement with the experimental values. So, both methods are reliable for prediction of SH parameters for the low‐spin d5 ions in crystals. The signs of hyperfine structure constants Ai are also suggested from the calculations. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical description of energy spectra of nanostructures assuming specular reflection of electron from the structure boundary
Authors: Vieira V. R. , Vorobiev Y. V. , Horley P. P. , Gorley P. M.
Published: September 2008

The quantum mechanical description of an electron in a nanostructure (like quantum dot, quantum well, organic dye molecule, etc.) strongly depends upon the boundary conditions applied. The classic free electron molecular orbital approximation uses the impenetrable walls conditions which could only be applied to the structures of the simplest geometry, and do not reflect the real character of the interaction of an electron with the structure's boundary, which in many cases is a specular (mirror‐like) reflection. We attempted to introduce the “mirror ” boundary conditions in the treatment of a particle (electron) confined in quantum wells (nanostructures) of several different geometries, assuming that for any point inside the well we could find the corresponding points reflected by all the structure “walls”, and write the boundary conditions as equivalency of the Ψ‐functions in real and reflected points. We show that for structures of sufficiently high symmetry these conditions are equivalent to the periodic ones considering that the quantum well studied together with its reflections form a periodic structure. The new “mirror” boundary conditions could be applied to a variety of cases (nanostructure's geometry), showing a reasonable agreement between the theory and the experiment without any adjustable parameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
FEMO modelling of optical properties of natural biopolymers chitin and chitosan
Authors: Luna‐Bárcenas G. , Gonzalez‐Campos B. , Elizalde‐Peña E. A. , Vivaldo‐Lima E. , Louvier‐Hernández J. F. , Vorobiev Y. V. , González‐Hernández J.
Published: September 2008

Chitin and its derivative chitosan are widely used in the food, cosmetic, agricultural and biomedical industries because of their physicochemical and biocompatible properties. In this work, we studied thin films of both materials prepared by a solvent‐cast method. The optical properties were investigated in the UV‐VIS and infrared (IR) spectral regions; both biopolymers exhibit similar absorption bands characterized by two regions at 250–500 nm and at 850–1300 nm. Chitin and chitosan have practically the same parameters of a crystalline structure. We assume that these features (similarity of the structure and of the optical properties) are not just the coincidence but reflect the essential relation between the crystalline structure symmetry and the electronic transitions. The later was modeled on the basis of the quantum mechanical Free Electron Molecular Orbital approximation, using the new type, mirror‐like boundary conditions. The calculations made on the basis of the known parameters of crystalline structure give reasonable agreement with the experimental spectra without any adjustable parameters. The difference between the optical properties of the two materials in the IR region reflects the difference in their molecular structure and composition. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanoporous oxides of refractory metals: fabrication and properties
Authors: Lazarouk S. K. , Sasinovich D. A. , Borisenko V. E.
Published: September 2008

A new approach to fabrication of nanoporous oxides of refractory metals is presented. It is based on the magnetron co‐sputtering of aluminum and refractory metal (titanium, niobium or tungsten) followed by porous electrochemical anodization of the composite film and selective etching of alumina. The nanoporous oxide films with a thickness up to 5 µm were fabricated and studied. The porosity of the oxide films characterized by the surface area of 230 – 460 m2/cm3can betuned by the aluminum content in the as‐deposited composite films. The pore diameters are found to be varied in nanometer and subnanometer ranges. The parameters of porous titania within porous alumina matrix for different titanium concentrations are presented. The fabricated porous composite oxide films are characterized by the refractive index in the range from 1.45 to 1.77. The dielectric permeability for these films is found to be varied from 6.7 to 24. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Ga on the growth of NiSi2 on Si
Authors: Mogilatenko A. , Allenstein F. , Schubert M. A. , Falke M. , Beddies G. , Hinneberg H.‐J. , Neumann W.
Published: September 2008

The study reports on the structure of thin ternary NiGaxSi2–x silicide layers grown on Si(001) by Ni/Ga codeposition at room temperature followed by subsequent annealing. The influence of both the Ga content and the annealing temperature on the phase formation and orientation of the layers was investigated for the first time. Addition of Ga leads to a decrease of the disilicide formation temperature down to less than 500 °C. Island formation is observed for the Ga content of 0.17 after annealing above 900 °C. The NiSi2‐xGax islands grow with a NiSi2–xGax(110) ‖ Si(001) texture. In contrast, closed epitaxial NiSi2–xGax layers of A‐type are obtained for the Ga content of 0.28 after annealing at 900 °C. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computer‐assisted analysis of TEM diffraction contrast images of (In,Ga)N/GaN nanostructures
Authors: Manolaki P. , Häusler I. , Kirmse H. , Mogilatenko A. , Neumann W. , Smałc‐Koziorowska J. , Skierbiszewski C.
Published: September 2008

III‐nitride semiconductor nanostructures are subject of intense studies with respect to their optoelectronic, structural and chemical properties. Important parameters for the wavelength of the emitted light are the chemical composition and the dimensionality of the nanostructures. Transmission electron microscopy is used to determine these characteristics at a nanometer scale. In this work, the information provided by diffraction contrast images of (In,Ga)N/GaN quantum wells (QWs) is studied. Experimental dark‐field images alternatively using the 0001 and the 0002 reflection show a different contrast regime. In order to understand the contrast, one has to calculate the intensity Ig of the individual diffracted beam g. The intensity of the 0002 beam is a function of the sum of the atomic scattering amplitudes of the group III and the group V element. Consequently, the 0002 reflection is strain sensitive. According to the kinematical theory the 0001 reflection is forbidden. However, it is excited in the experiment. Therefore, dynamical effects have to be taken into account. The corresponding intensity is calculated by the Howie‐Whelan equations. It turns out that the intensity of the 0001 beam strongly depends on the In content of (In,Ga)N. A good agreement of intensity profiles of 0001 dark‐field images compared to the theory is found. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deposition and electrical characterization of hafnium oxide films on silicon
Authors: Verrelli E. , Tsoukalas D. , Kouvatsos D.
Published: September 2008

Hafnium oxide dielectric is under intense investigation in recent years as a new high‐k insulator to replace silicon dioxide thus allowing further device scaling in silicon technology. In this work we investigate HfO2 deposited films using RF reactive sputtering technique and we present results on their electrical characterization using MOS capacitors. The HfO2 films have been sputtered on n or p‐type Si substrate from high purity HfO2 target at low deposition rate (0.1 Å/s) monitored by a quartz crystal. After deposition of the insulator aluminum has been evaporated and patterned to form MIS capacitors. In this paper we investigate the effect of deposition parameters and post‐deposition‐annealing on the electrical properties of the HfO2 films. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron microscopy investigation of extended defects in a‐plane gallium nitride layers grown on r‐plane sapphire by molecular beam epitaxy
Authors: Smalc‐Koziorowska J. , Komninou Ph. , Sahonta S.‐L. , Kioseoglou J. , Tsiakatouras G. , Georgakilas A.
Published: September 2008

The interfacial structure and extended defects in a‐plane (1120)‐oriented GaN layers are investigated using conventional and high resolution transmission electron microscopy (HRTEM). The a‐plane GaN epilayers have been grown by nitrogen rf plasma source molecular beam epitaxy (RFMBE) on r‐plane sapphire substrates, which have been nitrided either at 200 °C or at 800 °C for one hour. A thin interfacial layer of strained AlN, with an average thickness of about 1 nm, was formed during nitridation of the sapphire surface at both temperatures. The extended defects observed in the GaN layers are predominantly threading dislocations and basal stacking faults (BSFs), which originate from the GaN/sapphire interface. The threading dislocation density is slightly reduced in the film nitrided at 800 °C, as is the density of inversion domains, although stacking fault density does not appear to change with nitridation conditions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Flexible organic light emitting diodes (OLEDs) based on a blue emitting polyfluorene
Authors: Vasilopoulou M. , Palilis L. C. , Botsialas A. , Georgiadou D. G. , Bayiati P. , Vourdas N. , Petrou P. S. , Pistolis G. , Stathopoulos N. A. , Argitis P.
Published: September 2008

Flexible OLEDs were demonstrated using a highly efficient blue electroluminescent polyfluorene derivative. The flexible devices were fabricated on indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates with a sheet resistance of 35 Ω per sq. The emitting layer was poly[9,9‐di‐(2′‐ethylhexyl)fluorenyl‐2,7‐diyl] (PF). A significant improvement of the luminance and device efficiency was achieved by confining the exciton formation zone within PF by two wide band‐gap materials, namely PVK as a hole transport layer (HTL) and an inorganic oxide layer (IOL) as an electron transport and hole blocking layer. In order to achieve full‐color LEDs based on a common host material, we probed the use of suitable dye emitters dispersed in PF at appropriate concentrations. The selection of the emitters is based on their capability to be effective energy transfer acceptors from the blue emitting PF. In particular, energy transfer was demonstrated from blue to green for PF‐doped with the green dye emitter 1‐[4‐(dimethylamino)phenyl]‐6‐phenylhexa‐1,3,5,‐triene (DMA‐DPH), and from blue to red for PF‐doped with the red dye emitter (4‐dimethylamino‐4′‐nitrostilbene) (DANS). This demonstration paves the way for developing highly efficient blue, green and red flexible OLEDs based on a common blue emitting PF host. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Estimation of metallic contact effects on the performance of (SI) GaAs soft X‐ray radiation detectors
Authors: Theonas V. , Konstantinidis G. , Papaioannou G.
Published: September 2008

Semi‐insulating (SI) GaAs offers an attractive choice as a room temperature electromagnetic radiation detector, due to the high mean atomic number of the compound, the relatively low radiation ionization energy and high carrier's mobility. Standard detector configuration consists on a metal alloy Ohmic and a rectifying Schottky contact on either side of GaAs substrate. Metallic contacts, upon irradiation, inject fast electrons towards GaAs. These injected electrons provide an excess charge build‐up in the detectors active region. We investigated the contact thickness effect in charge build‐up and the consequent detector photo‐response, upon detectors irradiation by soft X‐ray photons. The secondary electrons induced excess photo‐current was experimentally verified at low bias conditions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Femtosecond laser‐assisted formation of channels in sapphire using KOH solution
Authors: Juodkazis Saulius , Nishi Yasufumi , Misawa Hiroaki
Published: September 2008

We report on wet etching of photomodified regions in crystalline sapphire using KOH solution. Tightly focused femtosecond laser pulses (150 fs at 800 nm wavelength) were used to create void structures enclosed in an amorphised sapphire shell inside the bulk of a crystalline host. The diameter of the amorphous regions can be controlled by pulse energy and was typically 0.5–1.5 µm. The etching rate depends on the distance between adjacent irradiation spots, pulse energy, concentration of etchant and ultrasonic agitation.

magnified image

Amorphised sapphire is etched out in KOH solution.

(© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Naringenin and hesperetin, two flavonoids derived from Citrus aurantium up‐regulate transcription of adiponectin
Authors: Liu Li , Shan Song , Zhang Kun , Ning Zhi‐Qiang , Lu Xian‐Ping , Cheng Yi‐Yu
Published: September 2008

The dried, immature fruit of Citrus aurantium L., ‘Zhiqiao’ in Chinese, has been used to treat cardiovascular diseases in traditional Chinese medicine for centuries. Naringenin and hesperetin and their glycosides present in considerable amounts (about 10∼15%) in the herb. The aim of this study is to test whether naringenin and hesperetin influence adiponectin expression, which plays an important role in glucose and lipid metabolism with antiatherogenic and anti‐inflammatory properties. Treatment with naringenin and hesperetin enhanced adiponectin transcription in differentiated 3T3‐L1 cells. Both naringenin and hesperetin induced peroxisome proliferator‐activated receptor (PPAR)γ‐controlled luciferase expression in a dose‐dependent manner (20–160 µM), whereas only naringenin possessed significant activity to activate PPARα. These results suggested the two flavonoids might exert antiatherogenic effects partly through activating PPAR and up‐regulating adiponectin expression in adipocytes. Our findings give new insight for the molecular explanations for the therapeutic effects of Zhiqiao. Copyright © 2008 John Wiley & Sons, Ltd.
On the effects of sampling parameters when surveying distribution vibrations
Authors: Rouillard Vincent , Lamb Matthew
Published: September 2008

This paper presents the initial outcomes of a study aimed at better understanding the effects of recording parameters on the outcomes of distribution surveys. With the advent of vibration recorders with increasing capacity, there has been a corresponding increase in the number of studies aimed at evaluating and characterizing the random vibrations generated by transport vehicles across a wide variety of distribution environments. Oftentimes, the sampling and recording parameters used in these studies are not given adequate attention, resulting in statistical estimates that are open to interpretation. The paper shows how the selection of the sampling and recording parameters can have significant effects on much used descriptors of random vibration processes such as the average power spectral density (PSD), the peak‐hold PSD and the root mean square distribution. The paper shows that the results of vibration surveys are most sensitive to the sampling period, especially when the vibrations are highly non‐stationary. The paper concludes by making specific recommendations for configuring high‐capacity vibration recorders to ensure that vibration surveys yield statistically sound results. Copyright © 2008 John Wiley & Sons, Ltd.
Accelerated proteolysis in alternating electric fields for peptide mapping
Authors: Wang Sheng , Bao Huimin , Liu Ting , Zhang Luyan , Yang Pengyuan , Chen Gang
Published: September 2008

Sinusoidal alternating voltages (typically 5 V) were employed to enhance the efficiency of proteolysis for peptide mapping in this work. Protein solutions containing trypsin were allowed to digest with the assistance of alternating electric fields (AEFs) between a pair of platinum wire electrodes in Eppendorf tubes. The feasibility and performance of the novel proteolysis approach were investigated by the digestion of several standard proteins. It was demonstrated that AEFs significantly accelerated in‐solution proteolysis and the digestion time was substantially reduced to 5 min. The digests were identified by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) with sequence coverages that were comparable to those obtained by using conventional 12‐h in‐solution proteolysis. The suitability of AEF‐assisted proteolysis to real protein samples was demonstrated by digesting and identifying human serum albumin in gel separated from human serum by sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS‐PAGE). The present proteolysis strategy is simple and efficient and will find a wide range of applications in protein identification. Copyright © 2008 John Wiley & Sons, Ltd.
The fallaxidin peptides from the skin secretion of the Eastern Dwarf Tree Frog Litoria fallax. Sequence determination by positive and negative ion electrospray mass spectrometry: antimicrobial activity and cDNA cloning of the fallaxidins
Authors: Jackway Rebecca J. , Bowie John H. , Bilusich Daniel , Musgrave Ian F. , Surinya‐Johnson Kathy H. , Tyler Michael J. , Eichinger Peter C. H.
Published: September 2008

The glandular skin secretion of the Eastern Dwarf Tree Frog Litoria fallax contains nine peptides named fallaxidins. The sequences of these peptides were elucidated using a combination of positive and negative electrospray mass spectrometry together with Edman sequencing. Among these peptides are: (i) fallaxidins 1.1 and 2.1 which have the sequences YFPIPI‐NH2 and FWPFM‐NH2. The activities of these peptides are unknown, but it has been shown that they are not smooth muscle active, opioids or antimicrobially active, nor do they effect proliferation of lymphocytes; (ii) two weakly active antibiotics, fallaxidins 3.1 and 3.2 (e.g. fallaxidin 3.1, GLLDLAKHVIGIASKL‐NH2), and a moderately active antibiotic fallaxidin 4.1 (GLLSFLPKVIGVIGHLIHPPS‐OH). Fallaxidin 4.1 has an unusual sequence for an antibiotic, containing three Pro residues together with a C‐terminal CO2H group. cDNA cloning has confirmed the identity of the nine isolated peptides from L. fallax, together with five additional peptides not detected in the peptide profile. The pre‐regions of the nine preprofallaxidins are conserved and similar to those of the caerin peptides from L. caerulea and L. splendida, suggesting that the fallaxidin and caerin peptides, although significantly different in sequence, originated from a common ancestor gene. Copyright © 2008 John Wiley & Sons, Ltd.
Weight loss and isotopic shifts for water drops frozen on a liquid nitrogen surface
Authors: Eguchi Keiko , Abe Osamu , Hiyama Tetsuya
Published: September 2008

A liquid nitrogen freezing method was used to collect raindrops for the determination of isotope‐size distribution. Water drops that fall onto a surface of liquid nitrogen stay suspended for 10 to 20 s, until their temperature reaches the Leidenfrost point (126 K). As their temperature falls to the freezing point, they release their heat by thermal conduction. At the freezing point, latent heat of fusion is released, along with a significant loss of water. After freezing completely, the ice droplets stay suspended, cooling by thermal conduction until they reach the Leidenfrost point. They then lose buoyancy and start sinking. Consistent isotopic changes of 1.5 ± 0.4 and 0.33 ± 0.05‰ for hydrogen and oxygen, respectively, were found for droplets with radii between 1.0 and 1.5 mm. Isotope fractionation appeared to occur at the same time as water loss, as the droplets were freezing, in what was probably a kinetic effect. Copyright © 2008 John Wiley & Sons, Ltd.
Hand‐held robotic instrument for dextrous laparoscopic interventions
Authors: Piccigallo Marco , Focacci Francesco , Tonet Oliver , Megali Giuseppe , Quaglia Claudio , Dario Paolo
Published: September 2008

Background

Surgical instruments used in many types of minimally invasive procedures are rigid or only limitedly flexible. Some common tasks like suturing, require precise and dextrous movements that are difficult to perform by means of instruments with limited degrees of freedom (DOF).

Methods

A hand‐held lightweight and ergonomic robotic instrument with a 3‐DOF roll‐pitch‐roll end‐effector has been developed, which can be controlled by the surgeon with one hand like a conventional instrument.

Results

The instrument is composed by a handle part and an end‐effector. The handle part has been developed taking into account a control mode study for laparoscopic instruments and it allows direct mapping between the orientation of handle and that of the end‐effector.

Conclusion

The instrument presented is the result of a global study involving mechanical, electronic and ergonomic aspects, with the aim of developing an instrument that enhances the dexterity of the surgeon while having an intuitive interface. Copyright © 2008 John Wiley & Sons, Ltd.
Real‐time motion tracking in image‐guided oral implantology
Authors: Chen Xiaojun , Lin Yanping , Wu Yiqun , Wang Chengtao
Published: September 2008

Background

As a crucial part of an image‐guided oral implantology system (IGOIS), intra‐operative motion tracking is important in terms of accuracy and efficiency. The tracking method, including the relevant algorithms, is described in detail.

Methods

The conventional CAD method is proposed to build the three‐dimensional (3D) surgical instrument models. With the application of the optical tracking device, calibration can be carried out. Three tracking algorithms are presented, and ‘tracking based on registration of RCS to VCS’ is regarded as the most efficient of these. In order to evaluate the tracking accuracy, the landmark coordinates are respectively obtained through pre‐operative CT data and intra‐operative tracking, so that the deviation can be calculated.

Results

The result data reveal that FRE and TRE of IGOIS are, respectively, 0.27 ± 0.11 mm and 0.77 ± 0.04 mm through a phantom experiment.

Conclusions

The experiment demonstrates the accuracy and reliability of IGOIS. The tracking method can be extended to other surgical navigation systems in various areas. Copyright © 2008 John Wiley & Sons, Ltd.
The kids coping scale
Authors: Maybery Darryl , Steer Sharon , Reupert Andrea , Goodyear Melinda
Published: September 2008

The measurement of stress and coping in adolescents has received some attention; however, the understanding and development of measures of how children cope has not kept pace. This study reports the conceptual development and psychometric properties of the Kids Coping Scale (KCS), a brief self‐report measure of problem, emotion and social support coping dimensions. Participants were 834 children aged 7–13 years of whom 390 were male (48.6 per cent) with a mean age of 9.88 years and 415 were female (49.6 per cent) with a mean age of 9.87 years. Principal components analysis did not support a hypothesized three‐factor structure; however a clear two‐factor structure (cross‐validated) distinguishing problem and emotion‐focused coping actions did emerge. The KCS returned low to moderate levels of internal consistency and low to moderate correlations with other relevant constructs (e.g. self esteem, parent responded strengths and difficulties). The findings highlight a clear problem‐ and emotion‐focused structure in a brief measure considered suitable for children 7 years and above. Weaknesses of the scale are outlined along with implications for the future developments to the KCS being identified. Copyright © 2008 John Wiley & Sons, Ltd.
Competitive dynamics, strategic consistency, and organizational survival
Authors: Lamberg Juha‐Antti , Tikkanen Henrikki , Nokelainen Tomi , Suur‐Inkeroinen Henri
Published: September 2008

This study investigates strategic consistency in competitive behavior. We construct a logically consistent evolutionary model, providing a causal argument to link a level of strategic consistency to long‐term organizational survival. According to our results, strategic consistency seems to be related to both organizational survival and the most efficient change over time concerning the key elements of a firm's strategy. One of the benefits of the model is that some of the components and processes may be manipulated through experimental or simulation interventions. This means that the model can be formally tested in future studies and managers can use it to fine‐tune patterns of competitive behavior. Copyright © 2008 John Wiley & Sons, Ltd.