bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of phases in an Al casting alloy by synchrotron tomography
Authors: Tolnai Domonkos , Degischer Hans Peter , Lendvai János
Published: June 2009

The microstructure of a gravity cast aluminium alloy is investigated, containing 8 wt% Si, 5 wt% Mg as alloying elements, and 0.6 wt% Fe as main impurity. The solidification starts with the formation of α‐Al dendrites, which are presented after subtraction of the interdendritic eutectic regions. There, α‐Al/Mg2Si eutectic solidifies from the remaining Mg‐ and Si‐rich liquid forming coral‐like so‐called ‘Chinese script’ Mg2Si. Simultaneously, an AlFeSi phase solidifies in 2D shapes. At last, the remaining liquid freezes as fine structured α‐Al/Mg2Si/Si ternary eutectic. Synchrotron tomographic measurements were carried out at ESRF ID19, to reveal the 3D microstructure with a spatial resolution of <1 µm. The phases of the eutectics, the AlFeSi phase and the α‐Al dendrites could be segmented, and quantitatively analysed by 3D image processing and analysis.
A dynamical theory for the X‐ray diffraction from the partially relaxed layers
Authors: Benediktovich Andrey , Feranchuk Ilya
Published: June 2009

The dynamical theory for X‐ray diffraction from the bilayer crystal structure with different lateral periods of the crystal unit cells (lateral mismatch) is considered in the present paper. The amplitudes of the principal diffraction waves and all harmonics conditioned by the lateral mismatch are calculated. The formation of the Bragg peaks is analysed taking into account the sphericity of the incident beam wave front set. The connection between the parameters of the coherent diffraction potential in the partially relaxed (epitaxial) crystals and the microscopic characteristics of the dislocations is also discussed.
In‐phase and anti‐phase interference fringes in Laue case
Authors: Negishi Riichirou , Fukamachi Tomoe , Yoshizawa Masami , Hirano Kenji , Hirano Keiichi , Kawamura Takaaki
Published: June 2009

By using X‐rays from synchrotron radiation, we measured the rocking curves due to only the imaginary part of the atomic scattering factor in Laue case. The interference fringes are observed which are totally different from the Pendellösung fringe. The fringes of the diffracted and transmitted rocking curves are in‐phase with each other. We studied the origin of the in‐phase fringes by using the complex dispersion surface and the electric field in the crystal, and also the relation with a coupled pendulum.
From nanoislands to nanowires: Growth of germanium on gallium‐terminated silicon surfaces
Authors: Schmidt Th. , Flege J. I. , Speckmann M. , Clausen T. , Gangopadhyay S. , Locatelli A. , Mentes T. O. , Heun S. , Guo F. Z. , Sutter P. , Falta J.
Published: June 2009

The influence of Ga pre‐adsorption on Si(111), Si(113) and Si(112) surfaces on Ge growth has been investigated by low‐energy electron diffraction and microscopy as well as X‐ray photoemission spectroscopy. On Si(111), step edges and substrate domain boundaries are decorated with Ga at high deposition temperatures, enabling selective growth and alignment of three‐dimensional Ge islands on a chemically modulated surface. On Si(113), a morphological modulation is achieved by Ga saturation, as the Si substrate decomposes into an ordered array of (112) and (115) facets. This results in the growth of Ge islands aligned at the facets. These islands exhibit an anisotropy, as they are elongated along [$1\bar 10$]. Ga pre‐adsorption on Si(112) smoothens the initially faceted bare surface, and subsequent Ge growth leads to the formation of nanoscale Ge wires. The results are discussed in terms of surface chemistry, as well as diffusion and strain relaxation anisotropy.
Anomalous X‐ray scattering study of the local structure in Ge‐Se glasses
Authors: Hosokawa S. , Oh I. , Sakurai M. , Pilgrim W.‐C. , Boudet N. , Bérar J.‐F.
Published: June 2009

Anomalous X‐ray scattering experiments on glassy GexSe1−x semiconductors have been carried out at energies close to the Ge and Se K edges in a wide concentration range from x = 0.15 to 0.333 across the rigidity percolation threshold composition of x = 0.20. The total structure factors, S(Q), show considerable variation with x in both the position and intensity of the prepeak at about 10 nm−1, while in the remaining Q range, it stays almost unchanged. The differential structure factors, ΔiS(Q), comprise characteristic features, depending on the absorption edges. Comparing them suggests that the prepeak indicating the existence of intermediate‐range order (IRO) purely originates from the Ge‐Ge partial correlations. In contrast to the S(Q), the prepeak in ΔGeS(Q) changes very slightly with varying x down to x ∼ 0.20, suggesting that the prepeak height in SGeGe(Q) largely enhances with decrease in the Ge concentration, in particular at the the rigidity percolation threshold composition. However, a sudden decrease and a shift of the Q position are seen at the Ge concentration less than the stiffness transition composition, which may relate to the sudden decrease of the GeSe4–GeSe4 connections in the floppy region of this glassy system.
Integrated intensities in Laue–Bragg cases for non‐absorbing crystals in X‐ray dynamical diffraction
Authors: Saka Takashi
Published: June 2009

Integrated power ratios in Laue–Bragg cases are obtained for non‐absorbing crystals. The reciprocity theorem is used to show that wave fields on exit surfaces in Laue–Bragg cases are identical to crystal wave fields of the Bragg case. The formulae are expressed analytically by a combination of modified Bessel and Struve functions of the first order.
High‐resolution three‐dimensional reciprocal space mapping of semiconductor nanostructures
Authors: Mariager Simon O. , Schlepütz Christian M. , Aagesen Martin , Sørensen Claus B. , Johnson Erik , Willmott Philip R. , Feidenhans'l Robert
Published: June 2009

By combining a 2D PILATUS 100 K detector and a surface diffractometer, high‐resolution 3D reciprocal space maps with a resolution up to 2 × 10−3 A−1 have been obtained, at an acquisition speed of 20 min per Bragg point. To illustrate the possibilities, the shape and facets of molecular beam epitaxy grown GaAs nanowires are identified by studying the diffuse scattering around Bragg points from the different crystal structures in the wires. The wires are bound by {111} facets from alternating domains with zincblende structure and its twin, creating a microfaceted wire with a hexagonal cross‐section.

magnified image

Isosurface of a [$11\bar 1$] Bragg point from a GaAs nanowire with crystal truncation rods originating from the wires' microfacets.
A combined X‐ray, ellipsometry and atomic force microscopy study on thin parylene‐C films
Authors: Flesch Heinz‐Georg , Werzer Oliver , Weis Martin , Jakabovič Ján , Kováč Jaroslav , Haško Daniel , Jakopič Georg , Wondergem Harry J. , Resel Roland
Published: June 2009

Parylene‐C thin films in a thickness range from 7 to 35 nm are deposited on silicon oxide and investigated for their structural and morphological properties by different methods. It is shown that spectroscopic ellipsometry (SE) is a powerful tool to obtain spatially resolved information on the homogeneity of thin films revealing relative changes in layer thickness and in the refractive index. However, the results can be considerably improved in combination with X‐ray reflectivity (XRR) which provides highly accurate results on layer thickness. The layer thickness from XRR is used as a fixed input value for the evaluation of the ellipsometry data which reveals a layer thickness dependence of the refractive index in the thin film regime. The interface roughness is determined from XRR as well as the surface rms roughness which can be compared to the roughness found by atomic force microscopy (AFM) which varies between 0.5 and 2.0 nm. Both results for the roughness show excellent agreement. Additionally a correlation of the roughness and the deposition rate is found.
Lattice parameter determination by coincidental multi‐beam X‐ray diffraction
Authors: Borcha Mariana , Fodchuk Igor , Krytsun Igor
Published: June 2009

High‐precision determination of the absolute value of lattice parameter for cubic single crystals is demonstrated by the example of silicon using coincidental multi‐beam X‐ray diffraction realized by superposition of two three‐beam reflections at fixed sample temperature. Based on a semi‐kinematical approximation of X‐ray scattering theory, the algorithm for calculation of multi‐beam diffractograms is developed enabling a more thorough quantitative analysis of experimental results.
Nano‐lightsticks: polymer nanotubes with embedded chemiluminescent dopants
Authors: Lovera Pierre , Reynolds Kenneth , Redmond Gareth
Published: June 2009

Aligned arrays of perylene doped poly(methyl methacrylate) nanotubes are synthesized by solution assisted template wetting. Optical studies yield well resolved absorption and photoluminescence spectra consistent with good dopant dispersion throughout the host material. True color photoluminescence images of tubes also reveal uniform, characteristic bright blue, perylene emission. Blue perylene chemiluminescence is observed from nanotubes on exposure to a mixture of aqueous hydrogen peroxide and oxalyl chloride in hexane with a rapid emission decay being consistent with a fast reaction between reagents and dopants. Finally, by monitoring the behavior of individual nanotubes, it is shown that single tubes may act as nanoscale chemiluminescent light sources.
Charge transport property of one‐dimensional gold–polyaniline composite networks
Authors: Mallick Kaushik , Witcomb Michael J. , Strydom Andre M.
Published: June 2009

A facile synthesis route is described for the preparation of a gold–polyaniline nanocomposite material. The gold nanoparticles were highly dispersed and stabilized throughout the polyaniline fibers that formed a metal–polymer composite material. We measured the temperature‐dependent electrical conductivity of the metal–polymer composite material. The conductivity data are commensurate with the one‐dimensional geometry of the resultant material. The temperature dependence of the Hall coefficient on the composite is in evidence of a possible contribution of a charge carrier deficit and a temperature‐dependent mobility in this material.
Preparation of tin nanocomposite as anode material by molten salts method and its application in lithium ion batteries
Authors: Hassan Mohd Faiz , Guo ZaiPing , Du GuoDong , Wexler David , Liu HuaKun
Published: June 2009

A nanocomposite material (SnO2Co3O4) has been synthesized as an anode material for lithium‐ion batteries by the molten salt method. Characterization by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the composite has a small particle size. The electrochemical performance was examined, including the charge–discharge and cycling properties. The experimental results showed that the sample containing the highest amount of Co3O4 compound exhibited a specific capacity of 355 mAh g−1 after 40 cycles, with cycling at 70 mA g−1 (35.2% higher than for the sample containing a lower amount of Co3O4). It seems that increasing the amount of Co3O4 can give good capacity retention and high specific capacity.
Investigation on internal electric field distribution of organic light‐emitting diodes (OLEDs) with Eu2O3 buffer layer
Authors: Shi Shengwei , Ma Dongge
Published: June 2009

We have found that organic light‐emitting diode (OLED) performance was highly improved by using europium oxide (Eu2O3) as a buffer layer on indium tin oxide (ITO) in OLEDs based on tris‐(8‐hydroxyquinoline) aluminium (Alq3), which showed low turn‐on voltage, high luminance, and high electroluminescent (EL) efficiency. The thickness of Eu2O3 generally was 0.5–1.5 nm. We investigated the effects of Eu2O3 on internal electric field distributions in the device through the analysis of current–voltage characteristics, and found that the introduction of the buffer layer balanced the internal electric field distributions in hole transport layer (HTL) and electron transport layer (ETL), which should fully explain the role of the buffer layer in improving device performance. Our investigation demonstrates that the hole injection is Fowler–Nordheim (FN) tunnelling and the electron injection is Richardson–Schottky (RS) thermionic emission, which are very significant in understanding the operational mechanism and improving the performance of OLEDs.
Theoretical analysis of optical gain in PbSe/Pb1–xSrxSe quantum well lasers
Authors: Sun Y. H. , Xu L. J. , Zhang B. , Xu Q. F. , Wang R. , Dai N. , Wu H. Z.
Published: June 2009

In this article, theoretical calculation of optical gain has been performed for IV–VI lead salt PbSe/Pb1–xSrxSe quantum well lasers emitting at about 4–6 µm by using an analytic gain expression. The reduced density of states and interband transition matrix elements used in the calculation were derived in the framework of the k·p model. Peak optical gain as a function of carrier concentration and radiative current density was calculated. The material parameters and laser structures that affect device performance were analyzed in details.
Effect of rapid thermal annealing on the electrical and structural properties of Ru/n‐InP (100) Schottky rectifiers
Authors: Janardhanam V. , Kumar A. Ashok , Reddy M. Bhaskar , Reddy V. Rajagopal , Reddy P. Narasimha , Balamurugan A. K. , Tyagi A. K.
Published: June 2009

The effects of rapid thermal annealing on the electrical and structural properties of Ru/n‐InP Schottky diode have been investigated by current–voltage (I–V), capacitance–voltage (C–V), X‐ray diffraction (XRD) and secondary ion‐mass spectroscopy (SIMS) techniques. Results showed that the Schottky barrier height of the as‐deposited Ru/n‐InP has been found to be 0.53 eV (I–V) and 0.69 eV (C–V). The Schottky barrier height increased to 0.54 eV (I–V) 0.73 eV (C–V), 0.56 eV (I–V) and 0.78 eV (C–V) after annealing at 300 and 400 °C for 1 min in nitrogen ambient. Further increase in the annealing temperature up to 500 °C resulted in the increase of barrier height to 0.57 eV (I–V) and 0.80 eV (C–V). However, after annealing at temperature 600 °C, the barrier height decreases to 0.51 eV (I–V) and 0.67 eV (C–V). Based on the results of XRD and SIMS studies, the formation of indium phases at Ru/n‐InP interface could be the reason for the increase of barrier height upon annealing at 500 °C. The atomic force microscopy results showed that the surface morphology of the contact annealed at 600 °C is fairly smooth with a root mean square roughness of 1.8 nm.
Phase transitions and electrical conductivity of Bi‐doped La2Mo2O9 oxide ion conductors
Authors: Voronkova Valentina , Kharitonova Elena , Krasilnikova Alexandra
Published: June 2009

La2−xBixMo2Oy (x = 0, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08, 0.1, 0.16, 0.24, 0.3) ceramic samples have been characterized by X‐ray diffraction, differential scanning calorimetry (DSC) and conductivity measurements in order to assess the dynamics of the transitions between the low‐temperature (α), high‐temperature (β) and metastable (βms) phases. Bi doping to x ≥ 0.05 fully stabilizes the cubic phase, suppressing the β → α phase transition. In addition, DSC results demonstrate that considerable doping levels give rise to a small thermal event between 450 and 500 °C, which has been identified as the βms → β phase transition between cubic phases with static and dynamic oxygen disorder. In this temperature range, the conductivity of the doped materials experiences a transition from Arrhenius to Vogel–Tammann–Fulcher behaviour. Low bismuth concentrations have a significant effect on the conductivity of La2Mo2O9.
Green photoluminescence of SrGa2S4:Sn phosphors
Authors: Nagata Mutsumi , Okamoto Shinji , Tanaka Katsu , Sakai Toshikatsu , Tamaki Akira
Published: June 2009

The phosphor SrGa2S4:Sn exhibits a new green photoluminescence (PL) whose spectrum peaks at 534 nm. The phosphor also exhibits yellow and orange PL with very broad spectral bands when the excitation wavelength of the UV light is changed. These emissions are caused by the 5p–5s transition in the 5s2 configuration of Sn2+ ions occupying Sr2+ sites. The origin of the green emission was investigated by analyzing the PL excitation spectra and the electronic states of Sn2+ substituting at three different Sr2+ sites. The electronic states were analyzed in a first‐principles calculation of the density of states.
Use of nanoparticles for preparation of rare‐earth doped silica fibers
Authors: Podrazky Ondrej , Kasik Ivan , Pospisilova Marie , Matejec Vlastimil
Published: June 2009

A new approach to preparation of rare‐earth and aluminium doped silica fibers is presented in this paper. Common Modified Chemical Vapor Deposition (MCVD) technique and solution‐doping method were employed while nanoparticle dispersions were used instead of solutions for erbium and aluminium co‐doping. Prepared preforms were analyzed by refraction index profiler, EPMA and confocal microscopy. Attenuation refractive index profile and emission of erbium fluorescence were measured in fibers prepared from preforms. Resulting fibers show better homogeneity of dopants concentration distributions and significant increase in erbium emission at 1550 nm. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of stack number on the threshold current density and emission wavelength in quantum dash/dot lasers
Authors: Zhou D. , Piron R. , Dontabactouny M. , Homeyer E. , Dehaese O. , Batte T. , Gicquel M. , Grillot F. , Tavernier K. , Even J. , Loualiche S.
Published: June 2009

InAs quantum dash and dot (QDH and QD) lasers grown by molecular beam epitaxy on InP substrate are studied. The grown lasers with active zone containing multiple stacked layers exhibit lasing wavelength at 1.55 μm. On these devices, the experimental threshold current density reaches its minimum value for a double stacked QDH/QD structure. Other basic laser properties like gain and quantum efficiency are compared. QD lasers exhibit better threshold current densities but equivalent modal gain per layer than QDH. Finally, the analysis of the modal gain on QD laser structures shows a promising potential for improvement of the laser properties. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependence of a twofold magnetic behaviour of a nanoscopic metal/silicon hybrid system – a comparison between Ni/Si and Co/Si
Authors: Rumpf K. , Granitzer P. , Poelt P. , Krenn H.
Published: June 2009

The investigated hybrid nanocomposite consists of a porous silicon template with electrochemically embedded Ni or Co nanostructures and offers magnetic characteristics which can be tailored by the electrochemical process parameters during fabrication. A twofold magnetic behaviour can be observed, a first one due to the spinmagnetism at magnetic fields below the saturation magnetization of the deposited metals and a second non‐saturating term at higher fields (> 1 T up to 7 T) above the saturation magnetization.

In case of Ni deposited within the pores this non‐saturating term shows a paramagnetic characteristic and follows exactly the Curie‐Weiss law, whereas for Co/porous silicon samples the temperature dependent magnetization shows some deviations from the Curie Weiss law. In this high field region a difference in the temperature dependence between Ni and Co is observed whereas the non‐saturating term does not depend on the geometry of the embedded nanostructures in contrast to the ferromagnetic behaviour at lower magnetic fields. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature and voltage effects in high performance magnetic junctions
Authors: Silva H. G. , Pogorelov Y. G.
Published: June 2009

Based on a quantum ballistic description of spindependent electronic transport in perfect magnetic junctions, the corrections are analyzed to the quantum resonances in their magnetoresistance (MR), due to finite temperature and to finite electric field bias. Considering them separately (varying temperature at fixed field or varying field at fixed temperature), we found monotonously decreasing MR with temperature but non‐monotonously with field. The latter behavior suggests new means for effective tuning and control of these devices and the temperature effect sets the criteria for reaching the quantum enhanced performance in real conditions (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of hydrodynamic parameters of fluidized bed adsorption on purification of nano‐bioproducts
Authors: Jahanshahi Mohsen , Najafpour Ghasem , Ebrahimpour Melika , Hajizadeh Solmaz , Shahavi Mohammad H.
Published: June 2009

The biotechnology industry has recently been demanding nanoparticulate products (20‐200 nm) such as viruses, plasmids, virus‐like particles and drug delivery assemblies. Fluidized bed/expanded bed adsorption (EBA) is a technique that can be employed for nanoparticulate purification providing practical advantages such as the potential for direct process integration as has been seen with protein products. In the present work, the hydrodynamic behaviour of an expanded bed adsorption column for obtaining the optimal conditions of bovine serum albumin (BSA) nanoparticle recovery on streamline DEAE was studied. Residence time distribution (RTD) analysis was used to acquire hydrodynamic information from changes bed expansion, column diameter and settled bed height. Fluidization behaviour was predicted from the Richardson–Zaki correlation, with experimentally determined values of the expansion index. RTD showed axial dispersion increases with bed height as well as linear velocity. However, the effect of expansion degree of the bed on bovine serum albumin (BSA) nanoparticle purification was studied and the yield of recovery of BSA nanoparticle in optimal condition was 80.71%. Hydrodynamic behaviour of expanded bed adsorption and its potential for the purification and recovery of nanoparticle bioproducts is strongly discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MC simulations of water meniscus in nanocontainers: explaining the collapse of viral particles due to capillary forces
Authors: Serena P. A. , Douas M. , Marqués M. I. , Carrasco C. , Pablo P. J. de , Miranda R. , Carrascosa J. L. , Castellanos M. , Mateu M. G.
Published: June 2009

By using a lattice‐gas model, we report numerical simulation for the action of capillary forces of water confined at the nanoscale during desiccation of viruses. Results are compared with structural effects of desiccation measured by Atomic Force Microscopy on individual viruses of the bacteriophage ϕ 29 and the minute virus of mice (MVM).

Structural integrity is found for theMVM, but not for the ϕ 29. Numerical simulations show that in the desiccation process, the meniscus shape formed inside the capsids strongly depends on the virus symmetry. This suggests that capillary forces could play a key role on the explanation of the different measured collapse processes (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification and characterization of icosahedral metallic nanowires
Authors: Peláez Samuel , Guerrero Carlo , Paredes Ricardo , Serena Pedro A. , García‐Mochales Pedro
Published: June 2009

We present and discuss an algorithm to identify ans characterize the long icosahedral structures (staggered pentagonal nanowires with 1‐5‐1‐5 atomic structure) that appear in Molecular Dynamics simulations of metallic nanowires of different species subjected to stretching. The use of the algorithm allows the identification of pentagonal rings forming the icosahedral structure as well as the determination of its number np, and the maximum length of the pentagonal nanowire Lpm. The algorithm is tested with some ideal structures to show its ability to discriminate between pentagonal rings and other ring structures. We applied the algorithm to Ni nanowires with temperatures ranging between 4 K and 865 K, stretched along the [100] direction. We studied statistically the formation of pentagonal nanowires obtaining the distributions of length Lpm and number of rings np as function of the temperature. The Lpm distribution presents a peaked shape, with peaks locate at fixes distances whose separation corresponds to the distance between two consecutive pentagonal rings. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generating hypotheses about molecular structure–activity relationships (SARs) by solving an optimization problem
Authors: Ma Junshui , Tong Christopher , Liaw Andy , Sheridan Robert , Szumiloski John , Svetnik Vladimir
Published: June 2009

This paper proposes a new automatic hypothesis‐generation algorithm for structure–activity relationship (SAR) rules, which is capable of investigating chemical compound activities in the context of multiple substructure interactions. The algorithm is formulated as an optimization problem based on a carefully selected criterion, APostDiff(s), and the globally optimal solution to the optimization problem can be obtained with a fast search algorithm developed using the data‐mining concept known as frequent set. Three public datasets are used to demonstrate the proposed method. Copyright © 2009 Wiley Periodicals, Inc. Analysis and Data Mining 1: 161‐174, 2009
A unified approach for analyzing exchangeable binary data with applications to developmental toxicity studies
Authors: Dang Xin , Keeton Stephine Lena , Peng Hanxiang
Published: June 2009

In this article, we present a general procedure to analyze exchangeable binary data that may also be viewed as realizations of binomial mixtures. Our approach unifies existing models and is practical and computationally easy. Resulting from completely monotonic functions, we introduce a rich family of parametric parsimonious binomial mixtures, including the incomplete Beta‐, Gamma‐, Normal‐, and Poisson‐binomial, generalizing the Beta‐binomial. We show that the family is closed under convex linear combinations, products, and composites. We also give the moments and the Markov property of the family. With such distributions, we can perform statistical inference on correlated binary data and, in particular, overdispersed data. We propose a regression procedure that generalizes logistic regression. We provide a forward model selection procedure. We run a small simulation to validate the inclusion of the binomial distribution. Finally, we apply the proposed procedure to analyze the 2, 4, 5‐Trichlorophenoxyacetic acid and E2 data and compare the results with existing procedures. Copyright © 2009 John Wiley & Sons, Ltd.
Controlled Assembly of Highly Raman‐Enhancing Silver Nanocap Arrays Templated by Porous Anodic Alumina Membranes
Authors: Qiu Teng , Zhang Wenjun , Lang Xianzhong , Zhou Yongjin , Cui Tiejun , Chu Paul K.
Published: June 2009

A convenient nanoscale technique is reported for the fabrication of highly ordered hemispherical silver nanocap arrays templated by porous anodic alumina (PAA) membranes as robust and cost‐efficient surface‐enhanced Raman scattering (SERS) substrates. This geometry produces a high Raman signal due to its periodic hexagonal arrangements and control of the gap between the nanostructures in the sub‐10‐nm regime. The surface structure can be tuned further to optimize the enhancement factor according to optional PAA fabrication and silver deposition parameters. Finite‐difference time‐domain calculations indicate that the structure may possess excellent SERS characteristics due to the high density and abundance of hot spots.
A Change in Practice from Epidural to Intrathecal Morphine Analgesia for Hepato‐Pancreato‐Biliary Surgery
Authors: Sakowska Magdalena , Docherty Elizabeth , Linscott David , Connor Saxon
Published: June 2009

Background

This study was designed to audit the change of anesthetic practice from thoracic epidural analgesia (TEA) to intrathecal morphine (ITM) combined with patient‐controlled analgesia (PCA) for hepato‐pancreato‐biliary (HPB) surgery.

Methods

All patients who underwent major HPB surgery and received TEA or ITM from March 2005 to March 2008 were identified. Patients who received PCA alone were used for comparison. Data were retrospectively collected and analyzed for success of TEA, perioperative intravenous fluid (IVF) volume administered, hypotension, complications, and hospital stay.

Results

During the study period, 51 (32%) patients received TEA, 79 (49%) received ITM plus PCA opiate, and 31 (19%) received PCA alone. The incidence of postoperative hypotension was significantly higher in those who received TEA compared with those who received ITM (21/51 (41%) vs. 7/79 (9%), P < 0.001). The median (range) perioperative IVF administration was higher in the TEA group compared with the ITM group for both the first 24 h (6 (3–11) liters vs. 5 (3–11) liters, P < 0.05) and in total (15.5 (5–48.5) liters vs. 9 (3–70) liters, P < 0.001). Respiratory complications occurred in five (10%) of the TEA group compared with one (1%) in the ITM group (P < 0.05). The median (range) hospital stay was longer in the TEA group compared with the ITM group (9 (3–36) days vs. 7 (3–55) days, P < 0.01).

Conclusions

In a resource‐limited setting, ITM, compared with TEA, is associated with a reduced incidence of postoperative hypotension, reduced IVF requirements, shorter hospital stay, and lowers the incidence of respiratory complication.
Isolation of tetranucleotide microsatellite loci in the burrowing parrot (Cyanoliseus patagonus)
Authors: Klauke Nadine , Masello Juan F. , Quillfeldt Petra , Segelbacher Gernot
Published: June 2009

We isolated seven novel polymorphic microsatellite DNA loci from the burrowing parrot (Cyanoliseus patagonus) and optimised them for future studies of population differentiation and genetic variation. The loci were screened for polymorphism using 38 samples from wild individuals from three neighbouring colonies in Argentina. The primers amplified highly variable loci characterised by 3–10 alleles per locus and their observed and expected heterozygosities ranged from 0.15 to 0.78 and 0.15 to 0.81, respectively. When we analysed 52 samples across Argentina and Chile, we found strong genetic differentiation between the Chilean and the Argentinean subspecies as well as significant differentiation between two geographically separated subspecies within Argentina. Our results indicate the suitability of these microsatellites for investigating further questions regarding the population genetics in this species.
Overexpression of a FAD3 Desaturase Increases Synthesis of a Polymethylene‐Interrupted Dienoic Fatty Acid in Seeds of Arabidopsis thaliana L.
Authors: Puttick Debbie , Dauk Melanie , Lozinsky Sharla , Smith Mark A.
Published: June 2009

A cDNA encoding the Arabidopsis extraplastidic linoleate desaturase (FAD3) was overexpressed in the seeds of wild‐type Arabidopsis and in a mutant line that accumulates high levels of oleic acid. In the transformed wild‐type plants, linolenic acid (18:3Δ9,12,15) increased from 19% to nearly 40% of total seed fatty acids, with a corresponding decrease in linoleate content (18:2Δ9,12). In the high oleate mutant, a large increase in the level of a fatty acid identified by gas‐chromatography/mass‐spectrometry as mangiferic acid (18:2Δ9,15) was observed. The results demonstrate that the polymethylene‐interrupted dienoic fatty acid, mangiferic acid, can be produced in seed oil through the overexpression of a fatty acid n‐3 desaturase.
Exact boundary controllability for quasilinear wave equations in a planar tree-like network of strings
Authors: Gu Qilong , Li Tatsien
Published: June 2009

In this paper the local exact boundary controllability for quasilinear wave equations on a planar tree-like network of strings is established and the number of boundary controls is equal to the number of simple nodes minus 1.
Existence of weak solutions for a non-classical sharp interface model for a two-phase flow of viscous, incompressible fluids
Authors: Abels Helmut , Röger Matthias
Published: June 2009

We introduce a new sharp interface model for the flow of two immiscible, viscous, incompressible fluids. In contrast to classical models for two-phase flows we prescribe an evolution law for the interfaces that takes diffusional effects into account. This leads to a coupled system of Navier–Stokes and Mullins–Sekerka type parts that coincides with the asymptotic limit of a diffuse interface model. We prove the long-time existence of weak solutions, which is an open problem for the classical two-phase model. We show that the phase interfaces have in almost all points a generalized mean curvature.
Differential physiological effects during tonic painful hand immersion tests using hot and ice water
Authors: Streff Anouk , Kuehl Linn K. , Michaux Gilles , Anton Fernand
Published: June 2009

The cold pressor test (CPT) is an empirically validated test commonly used in research on stress, pain and cardiovascular reactivity. Surprisingly, the equivalent test with water heated to noxious temperatures (hot water immersion test, HIT) has not been thoroughly investigated. The aim of the present study was to characterize the physiological effects and psychophysics of both tests and to analyze whether the autonomic responses are mainly induced by baroreflexes or a consequence of the pain experience itself. The study consisted of a single session including one CPT (4 ± 0.2 °C) and one HIT (47 ± 0.5 °C; cut‐off point 5 min) trial performed on 30 healthy drug free volunteers aged 19–57 (median 24) yrs. The sequence of both trials was alternated and participants were randomly assigned to sequence order and parallelized with respect to gender. Physiological parameters (cardiovascular, respiratory and electrodermal activity) and subjective pain intensity were continuously monitored. In addition, pain detection and tolerance thresholds as well as pain unpleasantness were assessed. Both tests were comparable with regard to the time course and intensity of subjective pain. However, a significantly higher increase of blood pressure could be observed during the CPT when compared to the HIT. The HIT appears less confounded with thermoregulatory baroreflex activity and therefore seems to be a more appropriate model for tonic pain.
Central pain mechanisms following combined acid and capsaicin perfusion of the human oesophagus
Authors: Brock Christina , Andresen Trine , Frøkjær Jens Brøndum , Gale Jeremy , Olesen Anne Estrup , Arendt‐Nielsen Lars , Drewes Asbjørn Mohr
Published: June 2009

Visceral afferents originating from different gut‐segments converge at the spinal level. We hypothesized that chemically‐induced hyperalgesia in the oesophagus could provoke widespread visceral hypersensitivity and also influence descending modulatory pain pathways. Fifteen healthy volunteers were studied at baseline, 30, 60 and 90 min after randomized perfusion of the distal oesophagus with either saline or 180 ml 0.1 M HCl + 2 mg capsaicin. Electro‐stimulation of the oesophagus, 8 cm proximal to the perfusion site, rectosigmoid electrical stimulation and rectal mechanical and heat stimulations were used. Evoked brain potentials were recorded after electrical stimulations before and after oesophageal perfusion. After the perfusion, rectal hyperalgesia to heat (P < 0.01, 37%) and mechanical (P = 0.01, 11%) stimulations were demonstrated. In contrast, hypoalgesia to electro‐stimulation was observed in both the oesophagus (P < 0.03, 23%) and the sigmoid colon (P < 0.001, 18%). Referred pain areas to electro‐stimulation in oesophagus were reduced by 13% after perfusion (P = 0.01). Evoked brain potentials to rectosigmoid stimulations showed decreased latencies and amplitudes of P1, N1 and P2 (P < 0.05), whereas oesophagus‐evoked brain potentials were unaffected after perfusion. In conclusion, modality‐specific hyperalgesia was demonstrated in the lower gut following chemical sensitization of the oesophagus, reflecting widespread central hyperexcitability. Conversely, hypoalgesia to electrical stimulation, decreases in referred pain and latencies of evoked brain potentials was seen. This outcome may reflect a counterbalancing activation of descending inhibitory pathways. As these findings are also seen in the clinical setting, the model may be usable for future basic and pharmacological studies.
Needs and care of migrants considered as severely mentally ill – cross-sectional and longitudinal studies of a Swedish sample
Authors: Arvidsson H. , Hultsjö S.
Published: June 2009

Purpose

Higher incidence of mental illnesses and less access to care is previously reported concerning migrants but few studies focus on the needs and care of migrant groups in psychiatry. The aim of this study was to compare differences in needs and care between migrant and nonmigrant groups of severely and persistently mentally ill (SMI) after the 1995 Swedish mental health care reform.

Methods

In a Swedish area, inventories were made in 2001 and 2006 of persons considered as SMI. These persons were interviewed and their needs were assessed. In a cross-sectional study in 2006, needs and care were compared between migrants and nonmigrants. In a longitudinal study, migrants and nonmigrants interviewed in both 2001 and 2006 were compared concerning the development of needs and care.

Results

The needs of the migrant group were less taken care of. In 2006, there were more unmet needs in this group concerning accommodation, physical health, psychological distress, basic education and economy.

Conclusion

The improvement of groups considered as SMI concerning functional disability and efforts of care found in the actual area did not seem to include the migrant group, at least not to the same degree.
The Emotional Stroop task: A comparison between schizophrenic subjects and controls
Authors: Demily C. , Attala N. , Fouldrin G. , Czernecki V. , Ménard J.-F. , Lamy S. , Dubois B. , Thibaut F.
Published: June 2009

The colour-word Emotional Stroop task (ES task) has been proposed to assess the interferences between emotion and attention. Using this task, first, we examined how attention (using reaction times) can be modified by emotionally relevant words in schizophrenics as compared with controls as a function of the emotional significance of the word; second, we tested the assumption that schizophrenics with the most negative symptoms will show higher impairment in relationship to negative emotional words. In general, schizophrenics were slower to react. In both groups, mean reaction times were slower for emotional as compared with neutral words. No significant differences were observed between negative and positive words either in schizophrenics (n = 21) or in controls (n = 20). Even in the most negative schizophrenic patients, there were no differences between negative and positive words. There were no significant interactions between type of stimulus and any clinical variables (PANSS negative or non negative categorization, etc.). Also, there were no statistically significant correlations between reaction times and neuroleptic dosage or anhedonia scores. In conclusion, schizophrenia patients showed the same degree of interference from emotional words as compared with controls. Moreover, patients with a higher level of negative symptoms did not differently experience positive and negative words.
Patterns of caffeine consumption in psychiatric patients. An Italian study
Authors: Ciapparelli A. , Paggini R. , Carmassi C. , Taponecco C. , Consoli G. , Ciampa G. , Ramacciotti C.E. , Marazziti D. , Dell’Osso L.
Published: June 2009

Purpose

The aim of the present study was to explore and compare the caffeine intake, intoxication, withdrawal and dependence prevalence in Italian psychiatric patients and healthy subjects.

Materials and methods

Three hundred and sixty-nine out- and inpatients, suffering from different psychiatric disorders, and 104 healthy subjects were included in the study. They were assessed by the SCID and by a structured interview for caffeine intoxication and withdrawal and for substance dependence applied to caffeine use.

Results

Patients and healthy subjects did not differ in terms of current caffeine intake (mg/day, mean ± SD: 281 ± 325 vs. 288 ± 148, respectively), while the maximum lifetime intake of caffeine was significantly higher in the first group (mg/day, mean SD: 630 ± 549 vs. 504 ± 344, respectively; F = 4.897,p= .03) where it was significantly related to the CGI severity item scores (rho = .107;p= .04). In both patients and healthy subjects, a lower age was related to a higher current caffeine intake, while both current and maximum lifetime caffeine intake in the healthy subjects were significantly higher in men than in women. The patients suffering from eating disorders reported higher current caffeine intake than those with anxiety or mood disorders. The prevalence of dependence and intoxication was significantly higher in the patients than in the healthy subjects, without inter-group differences. Healthy subjects showed a trend towards a higher prevalence of withdrawal.

Conclusions

Our study highlights the need that a more accurate attention should be paid to the caffeine use which seems to be strongly, although generically, related to different psychiatric disorders.
Apolipoprotein-E gene variants associated with cardiovascular risk factors in antipsychotic recipients
Authors: Clark D. , Skrobot O.A. , Adebiyi I. , Susce M.T. , de Leon J. , Blakemore AI.F. , Arranz M.J.
Published: June 2009

Interest exists in identifying the factors that specifically contribute to the increased prevalence of cardiovascular disease observed in psychiatric disease. The apolipoprotein-E (APOE) gene codes for a protein that has a key role in metabolism of cholesterol and triglycerides, with increased levels of apoE found in specific areas of post-mortem schizophrenic brains. This study investigated whether apoE variants influence the prevalence of cardiovascular risk factors (obesity, diabetes and dyslipidaemia), in patients receiving antipsychotic treatment, due to extension of the risk seen in the general population, but also due to the role of the APOE gene in mediating antipsychotic-induced side effects. Seven polymorphisms (rs741780, rs483082, rs429358, rs7412, rs10119, rs439401 and rs405509) were genotyped in 427 American Caucasian patients who were either receiving, or had been prescribed risperidone. Our results support the hypothesis that APOE gene variants influence the prevalence of diabetes and possibly overweight in psychiatric patients. Unfortunately, due to the cross sectional nature of this study, the contribution of antipsychotic treatment was not determined. These associations warrant prospective study to assess interaction between APOE gene variants and the propensity of antipsychotics to induce cardiovascular risk factors.
Serious diabetes-specific emotional problems in patients with type 2 diabetes who have different levels of comorbid depression: A Polish study from the European Depression in Diabetes (EDID) Research Consortium
Authors: Kokoszka A. , Pouwer F. , Jodko A. , Radzio R. , Mućko P. , Bieńkowska J. , Kuligowska E. , Smoczyńska O. , Skłodowska Z.
Published: June 2009

Objective

Depression is a common psychiatric problem in patients with type 2 diabetes (DM2). A common view is that the burden of having DM2 contributes to the development of depression in DM2. Aim of the present study was to compare the levels of diabetes-specific emotional problems of DM2 patients with diagnosed depression with those with a subclinical form of depression and those without depression.

Methods

A cross-sectional study was conducted in 101 DM2 patients (51 men and 50 women, mean age = 63,17; SD = 10,74) who completed a standardized, structured psychiatric diagnostic interview (MINI), the Beck Depression Inventory, the Hamilton Depression Rating Scale as well as the Problem Areas in Diabetes (PAID) scale (a 20-item measure, with an overall scale measuring diabetes-related emotional distress and four subscales [negative emotions, treatment-related problems, food-related problems, lack of social support]).

Results

A depression diagnosis was made in 35% (n = 35) of the participants, 24% (n = 24) had a subclinical form of depression, 42% (n = 42) were not diagnosed with any kind of depressive disorder. Diabetes-specific emotional problems were most common in DM2 patients with a depressive disorder (significantly highest PAID score: 39) compared to patients with subclinical depression or no depression. In the group of non-depressed patients, only 14% agreed to have four or more (somewhat) serious diabetes-specific problems. In those with subclinical depression, this percentage was 42% and in those with a depressive disorder 49% (P < 0.001).

Conclusions

Diabetes-related emotional problems are particularly common among DM2 patients with comorbid clinical depression and to a lesser extent in patients with subclinical depression, compared to non-depressed DM2 patients. Male diabetes patients with a depressive disorder are particularly vulnerable to develop high levels of diabetes-specific emotional distress. Major differences between the three groups mainly concern the diabetes-specific problems connected with the illness.
Smoking ban in a psychiatry department: Are nonsmoking employees less exposed to environmental tobacco smoke?
Authors: Vorspan F. , Bloch V. , Guillem E. , Dupuy G. , Pirnay S. , Jacob N. , Lépine J.-P.
Published: June 2009

Staff members of psychiatric facilities are at high risk of secondhand smoking. Smoking exposure was assessed in 41 nonsmoking employees of a psychiatry department before and after a ban. Subjective exposure measures decreased in 76% of the subjects. Salivary cotinine decreased in the subsample of seven subjects with high pre-ban levels (32 ±8 vs 40 ± 17 ng/ml, p = .045).
Evaluation of the association between insight and symptoms in a large sample of patients with schizophrenia
Authors: De Hert M.A.F. , Simon V. , Vidovic D. , Franic T. , Wampers M. , Peuskens J. , van Winkel R.
Published: June 2009

Background

The objective of the present study was to examine the association of insight into the illness with demographic variables and symptomatology in a sample of 1213 patients with schizophrenia.

Method

Data were collected with the Psychosis Evaluation tool for Common use by Caregivers (PECC), a semi-structured interview evaluating five symptom domains of schizophrenia and the insight items ‘awareness of having a mental disorder’ and ‘attributing symptoms to a mental disorder’.

Results

Insight was positively associated with educational level and inversely with overall symptom severity, and the positive, negative, excitatory and cognitive symptom domains. At symptom level, the items ‘delusions’, ‘grandiosity’, ‘poor rapport’, ‘social withdrawal’ and ‘guilt feelings’ showed the strongest associations with both insight items. Overall, correlations between insight and symptomatology were modest, explaining less than 30% of the variance in insight.

Conclusion

Lack of insight in schizophrenia is partially explained by clinical symptoms and demographic measures.
Personality problems are considerably associated with somatic morbidity and health care utilisation
Authors: Olssøn I. , Dahl A.A.
Published: June 2009

Purpose

To explore the associations between the presence of personality problems and somatic morbidity and health care utilisation.

Methods

The Iowa Personality Disorder Screen was administered in order to identify persons with personality problems in a Norwegian population survey (the Oslo Health Study – HUBRO). Cases consisted of 369 individuals, 30, 40 and 45 years of age with personality problems matched on age and gender with five controls each. Data on somatic morbidity and health care utilisation were collected by questionnaires.

Results

The cases more frequently reported persistent muscular pain, asthma, fibromyalgia and alcohol problems than the controls. They also more often used nonprescribed analgesics and antidepressants. The cases more frequently had consulted a general practitioner (GP) in the last 12 months, less frequently got referral to somatic specialist care and were less satisfied with their last visit to a GP.

Conclusion

In this population based study, personality problems in young adults based on DSM-IV personality disorder criteria were associated with increased occurrence of somatic morbidity and primary health care utilisation. The relevance for GP to take personality problems into account during consultations is underlined and a method for doing so is suggested.