bluuebunny/crossref_metadata_2025 huggingface dataset:
MOVPE‐grown ZnSe/ZnSSe structures for blue VCSEL with resonant periodic gain
Authors: Korostelin Y. V. , Kozlovsky V. I. , Kuznetsov P. I. , Landman A. I. , Sannikov D. A. , Tiberi M. D.
Published: March 2006

The long period ZnSe/ZnSxSe1–x (x = 0.2–0.4) MQW structures for the electron beam longitudinally pumped laser were grown by metalorganic vapour phase epitaxy on ZnSSe substrates with 5–13° misorientation from (001) to (111)A crystal plane. The best structures with up to 40 QWs had mirror like surface and high intense cathodoluminescence at room temperature (RT). The substrates were cut from ZnSSe single crystals obtained by seeded physical vapour transport. Based on the obtained structures, the etalons were fabricated for electron beam pumping. Lasing at 445 and 460 nm was achieved at T = 80 K and RT, respectively. Output power of the laser was about 1 W at T = 80 K and much less at RT. Possible reasons are discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin flip Raman spectroscopy on heavily doped ZnMnSe layers
Authors: Lentze M. , Smith L. , Wolverson D. , Grabs P. , Geurts J. , Molenkamp L.
Published: March 2006

The influence of carrier concentration on electronic spin flip transitions in the conduction band of heavily doped diluted magnetic semiconductors is analysed experimentally by spin flip Raman spectroscopy (SFRS). Bulk‐like (Zn,Mn)Se epitaxial layers with electron concentrations between n = 1016 cm–3 and n = 1019 cm–3 are investigated. Spin flip Raman signals appear in samples with doping concentration up to 1018 cm–3, i.e., near the insulator‐to‐metal transition. Varying the doping level we observe a systematic broadening of SFRS linewidth with increasing electron concentration. Furthermore, the linewidth in backward scattering geometry is significantly higher than in forward scattering. Following theoretical predictions for doped samples, from this behaviour the values of spin diffusion coefficient Ds and spin relaxation time T2 are deduced. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication and characterization of polycrystalline bulk ZnO with large grain size of ∼100 µm by the spark plasma sintering
Authors: Kougo T. , Yoshikawa A.
Published: March 2006

We investigated to fabricate polycrystalline ZnO bulk crystal with large grain size up to 100 µm by the spark plasma sintering (SPS) in the atmosphere of low‐vacuum of ∼1 Pa air or in atmospheric pressure air. 1 µm average‐size ZnO powder of 99.999% purity was used as the raw material for sintering. The shape of samples was disk‐like of which diameter and thickness were 20 mm and 0.5–1.0 mm, respectively. We studied how the sintering conditions, in particular the sintering temperature and the applied pressure, affect the properties of sintered ZnO crystals. No additive to enhance the sintering process was used in this work. It was found that the SPS was very effective to enhance the sintering itself resulting in the grain size ranging from a few µm to ∼100 µm. Further the electrical properties of the sintered ZnO crystals were found to be very sensitive to the sintering conditions, i.e., their resistivity varied in the range from 0.02 Ω cm to ∼1000 kΩ cm depending on the grain size. The resistivity saturated in the order of 0.01 Ω cm when the grain size was above about 20 µm. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study on electrical properties of II‐VI‐based distributed Bragg reflectors
Authors: Otte Kai , Kruse Carsten , Dennemarck Jens , Hommel Detlef
Published: March 2006

The key technology for electrically pumped vertical‐cavity surface‐emitting lasers (VCSEL) is the realisation of high reflectivity Bragg Mirrors (DBRs) with sufficient conductivity in vertical direction. Several nand p‐doped DBRs, consisting of ZnSSe as high index and a MgS/Zn(Cd)Se superlattice (SL) as low index material were grown on GaAs substrates. Mesa structures were prepared and furnished with metal contacts. On the one hand a sufficient conductivity of n‐doped DBRs has been achieved. The conductivity depends strongly on the period and composition of the MgS/Zn(Cd)Se‐SL. On the other hand the p‐doped DBRs showed a resistance of several orders of magnitude higher and are unlikely to be used in VCSELs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterisation of Cd1–x–yZnxBeySe crystals by spectroscopic ellipsometry and luminescence
Authors: Wronkowska A. A. , Firszt F. , Arwin H. , Wronkowski A. , Wakuła M. , Strzałkowski K. , Paszkowicz W.
Published: March 2006

Optical and luminescence properties of Cd1–x–yZnxBeySe solid solutions grown in the composition range 0 < x < 0.15 and 0 < y < 0.30 by the high pressure Bridgman method are reported. Spectroscopic ellipsometry was employed for determination of spectral dependence of the complex dielectric function ε(E), refractive index n(E) and absorption coefficient α(E) in the photon energy range 0.75–6.0 eV. The dispersion of the refractive index of the alloys was modelled using a Sellmeier‐type relation. The excitonic band‐gap energies were estimated from the ellipsometric and photoluminescence measurements. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defect formation in CdTe during laser‐induced doping and application to the manufacturing nuclear radiation detectors
Authors: Gnatyuk V. A. , Aoki T. , Hatanaka Y. , Vlasenko O. I.
Published: March 2006

The peculiarities of electrical properties of In/CdTe/Au diodes, fabricated by the laser‐induced doping procedure, have been studied. The measurements of time dependences of reverse biased current of a great number of different samples revealed three types of the leakage current density variations with time. These variations were attributed to proper CdTe defects as well as point and extended defects generated in the act of laser‐induced doping of CdTe wafers and following fabrication of pixel detectors. The optimal conditions of laser‐induced In‐doping of CdTe wafers and formation of electrodes were elaborated. The fabricated detectors had sharp I‐V characteristics with a low leakage current, possessed a high energy resolution at room temperature and showed promise for nuclear radiation imaging devices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Far infrared selective absorption in uniformly iodine doped MBE CdTe/CdMgTe quantum wells – with no energetic scaling
Authors: Szot M. , Karpierz K. , Maude D. K. , Sadowski M. L. , Kossut J. , Grynberg M.
Published: March 2006

Magnetophotoconductivity spectra of uniformly doped CdTe/Cd0.8Mg0.2Te quantum wells are presented. They were taken for fixed photon energy causing the transitions between the shallow donor levels splitted by an external magnetic field. They exhibit a surprising lack of sensitivity on the photon energy – for the energy range 2.2–13 meV the peaks in the spectra are recorded at the same magnetic field. The results are understood by taking into account the existence of local potential fluctuations in the structure which do cause localization of conducting electrons. The absorption can always occur on donors located in different regions and it leads to the mentioned lack of energetic scaling. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical manifestation of ferromagnetic ordering in phosphorus‐doped semimagnetic semiconductor Zn1–xMnxTe
Authors: Van Khoi Le , Gałązka R. R.
Published: March 2006

Zn1–x Mnx Te semimagnetic semiconductor doped with phosphorus has been investigated by means of the resistivity, Hall effect, andmagnetic susceptibilitymeasurements. Itwas demonstratedthat in Zn1–x Mnx Te:P the Mn‐Mn antiferromagetic superexchange interaction can be controlled by changing the hole concentration and that the Mn‐Mn ferromagnetic interaction was observed at the hole concentration level of 5 × 1018 cm–3. This Mn‐Mn ferromagnetic interaction has resulted in a strong temperature dependence of the resistivity, which follows log ρ ∼ 1/T 2. A phenomenological calculation has been performed taking into account the magnetic contribution to the carrier binding energy. The calculation well describes the temperature dependence of the resistivity of the highly P‐doped Zn1–x Mnx Te crystals. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of CdSe/ZnSe nanostructures grown by MBE on virtual Si/Ge substrates
Authors: Onishchenko Evgeny E. , Kazakov Igor P. , Rzaev Murvetali M.
Published: March 2006

In this paper, the luminescent properties (5–300 K) of CdSe/ZnSe quantum dot structures grown on conventionally used GaAs(100) substrates and Si(100)/Ge virtual substrates are studied. It has been established that the quantum dot structures grown on different substrates exhibit comparable high luminescence efficiency. Two peaks were observed in the luminescence spectra of some samples grown on GaAs as well as Si/Ge substrates. They are attributed to the emission from two types CdSe islands (quantum dots) between which there is no efficient exciton transfer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of in situ annealing on CdSe quantum dots grown by ALE
Authors: Morrod J. K. , Graham T. C. M. , Warburton R. J. , Prior K. A.
Published: March 2006

The effect of increasing annealing times on the emission energies and dot densities of ZnSe/CdSe quantum dots has been studied. Ensemble PL carried out at 77 K demonstrates the energy shift of the main peak attributed to fractional monolayer islands, which is due to annealing. µPL conducted at 4 K was then used to study the increased spectral separation of the emission energies from SK dots. Finally, ex‐situ AFM measurements of two samples, showed a reduction in the Stranski‐Krastanow dot density of approximately one order of magnitude due to annealing. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Manipulation of exciton spin states in a dilute magnetic semiconductor by nanostructured ferromagnets
Authors: Halm S. , Seifert F. , Kümmell T. , Bacher G. , Schuster E. , Keune W. , Puls J. , Henneberger F.
Published: March 2006

A hybrid of nanostructured Fe/Tb multilayer ferromagnets and ZnCdMnSe dilute magnetic semiconductor (DMS) quantum well was studied by magneto‐micro‐photoluminescence (µPL) spectroscopy. When the sample is magnetized in an external magnetic field an additional fringe field from the nanomagnets effectively modulates the local exciton spin states in the quantum well (QW) due to the giant Zeeman effect. Observation of 1.5% of remanent PL polarization degree from the QW gives a direct proof of remanent exciton spin polarization in the DMS. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Internal laser parameters and optical properties of laser with CdSe quantum dots in ZnSe matrix
Authors: Lutsenko E. V. , Gurskii A. L. , Pavlovskii V. N. , Zubialevich V. Z. , Yablonskii G. P. , Sedova I. V. , Sorokin S. V. , Toropov A. A. , Ivanov S. V. , Kop'ev P. S.
Published: March 2006

Photoluminescence (PL), PL excitation (PLE) spectra as well as internal laser characteristics of CdSe quantum dots (QDs) in ZnSe matrix grown by molecular beam epitaxy (MBE) and multi‐cycle migration enhanced epitaxy (MEE) were investigated. The peak PL intensity of the CdSe QDs grown by MEE in an asymmetric waveguide is by one order of magnitude more than that of the CdSe QDs grown by MBE in a symmetric waveguide. As a result, the laser characteristics have been significantly improved. The internal laser parameters were estimated to be: ΓG0 ∼ 66 cm–1, ηi ∼ 13–17%, αi ∼ 5–15 cm–1 for MBE CdSe QDs and ΓG0 ∼ 69 cm–1, ηi ∼ 42%, αi ∼ 2–10 cm–1 for MEE CdSe QDs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and optical property characterizations of ZnTe:(Al,N) layers using two co‐doping techniques
Authors: Ichiba A. , Ueno J. , Ogura K. , Katsuta S. , Kobayashi M.
Published: March 2006

In order to get around the high and activated n‐doping levels for ZnTe, the co‐doping technique known as effective method to overcome the dopant compensation was explored. The co‐doping concept is to introduce two oppositely polar atoms at the same time in a 2:1 ratio, forming metastable three‐atom complexes located at adjacent crystal sites. In this study, two types of deposition process were considered to place the co‐dopants at the intended site, and the co‐doped ZnTe:(Al, N) layers were grown on (001) oriented ZnTe substrates by molecular beam epitaxy. From the low temperature PL spectra, the increase of Al activation was confirmed by using co‐doping sequences, and the activation of N dopant was also confirmed for one doping sequence even thought the doping level was maintained the same. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation of CdO dots on atomically flat ZnO surfaces
Authors: Ebihara M. , Suemune I. , Kumano H. , Nakashita T. , Machida H.
Published: March 2006

Atomically flat terraced ZnO surfaces were prepared with thermal annealing in air. CdO dots were successfully formed on the ZnO substrate surfaces with in‐situ post‐growth thermal annealing of CdO layers grown by metalorganic molecular‐beam epitaxy. Well‐organized alignment of the CdO dots along surface atomic‐step edges on the terraced surfaces is demonstrated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphology of CdSe/ZnSe quantum dots grown by MBE
Authors: Bougerol C. , André R. , Robin I. C. , Gilles B. , van Daele B. , van Tendeloo G.
Published: March 2006

The features of CdSe/ZnSe quantum dots (QDs) grown by molecular beam epitaxy at 280 °C and 240 °C are studied by transmission electron microscopy (TEM), atomic force microscopy (AFM) and photoluminescence (PL). The epitaxial structures consist of a single layer of CdSe islands sandwiched between two 40 nm thick ZnSe layers grown on a [100]‐oriented GaAs substrate. UHV‐AFM shows that islands are formed as a result of strain relaxation in 3 ML of CdSe pseudomorphically deposited on ZnSe. After encapsulation at 240 °C, there is no change in the QDs' morphology. On the other hand, at higher temperature, interdiffusion and segregation phenomena take place. Flat islands originating from a wetting layer and pointing to the substrate are observed, with a Cd concentration much lower in their center than at the outskirts. Both size and composition are consistent with the ∼2.35 eV PL energy that we measured. Moreover the unexpected QD morphology with Cd‐rich outskirts can explain why the PL decay time depends on the samples because the confinement of holes in the QD edges makes the electron‐hole overlap very sensitive to QD size. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anisotropic magnetic properties of Zn1–xCoxO thin films grown by pulsed laser deposition
Authors: Lee J. W. , Kuroda S. , Yamada S. , Takita K.
Published: March 2006

The anisotropic magnetic and magneto‐transport properties of Zn1–x Cox O thin films were investigated. By pulsed laser deposition (PLD) technique, the (0001) plane (c ‐plane) or (11‐20) plane (a ‐plane) Zn1–x Cox O layer was deposited on the c ‐surface or r ‐surface sapphire substrate, respectively, and magnetization and magnetoresistance (MR) measurements were performed with magnetic fields parallel or perpendicular to the film plane. It was found that the magnitudes of the magnetization and MR were larger when magnetic fields were applied along a ‐ or b ‐axis than those under magnetic fields along c ‐axis, irrespective of the growth orientation of the films. The consistency of the anisotropy between magnetization and MR is considered to originate from the anisotropic electronic state of Co d ‐electrons. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ZnO crystals for substrates in micro and optoelectronic applications
Authors: Grasza K. , Mycielski A. , Domagała J. , Domukhovski V. , Paszkowicz W. , Sakowska H. , Hofman W.
Published: March 2006

Zinc oxide crystals were grown by Chemical Vapour Transport using Contactless Crystal Growth technique. To apply powdered source material and long ampoules, modified temperature field was applied. 2.5 cm diameter crystals were obtained. The largest grains yielded 0.5 cm2 single crystalline substrates. The FWHM of the rocking curve was usually exceeding 60 arcsec, but areas with FWHM as low as 29 arcsec were also found. The electrical p‐type conductivity of As‐doped crystal was identified as increased arsenic content grain surface effect. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Applicability of ZnO single crystals for ultraviolet sensors
Authors: Masuoka F. , Ooba K. , Sasaki H. , Endo H. , Chiba S. , Maeda K. , Yoneyama H. , Niikura I. , Kashiwaba Y.
Published: March 2006

Photoconductivity of ZnO single crystals grown by a hydrothermal method for ultraviolet light was measured. The ZnO single crystals have photo response in a range of wavelengths shorter than 380 nm. O‐faces of ZnO single crystals of the c ‐plane showed higher photocurrents and wider spectral response than did Zn‐faces. It is thought that band bending at the surface regions of ZnO crystals is large at the O‐face but small at the Zn‐face, because the surface state density for electron capture at the O‐face was higher than that of the Zn‐face and, therefore, carriers generated at the surface region by UV light were effectively separated at the O‐face region before their recombination. The difference between photoresponces of the O‐face and the Zn‐face is also useful for determining the polarity of a ZnO crystal. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman scattering on Mn or Co doped ZnO crystals
Authors: Jouanne M. , Morhange J. F. , Szuszkiewicz W. , Gołacki Z. , Mycielski A.
Published: March 2006

Single crystals of bulk ZnO containing up to about 3% of Mn or Co were grown by chemical vapour transport method and characterized by Raman scattering. By comparison with Raman data taken on pure ZnO samples, a few new structures were observed in the spectra of the doped crystals. The determined frequencies of the new modes were compared with existing Raman data, corresponding to ZnO crystals containing various dopants, taken from the literature. A possible attribution of the observed modes to local impurity modes is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mobile donors in undoped ZnO
Authors: Markevich I. V. , Kushnirenko V. I. , Borkovska L. V. , Bulakh B. M.
Published: March 2006

Direct evidence that dominant shallow donors in undoped ZnO are mobile defects has been obtained. It has been found that these donors influence not only electrical conductivity, but also optical absorption and luminescence. Migration of mobile donors in crystal lattice, which can be already observed at 300 K, results in instability of ZnO characteristics. Common analysis of obtained results and literature data has led to the conclusion that dominant donors in undoped ZnO are zinc interstitials. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical properties of ZnO/GaN heterostructures and photoresponsivity of ZnO layers
Authors: Oh D. C. , Suzuki T. , Makino H. , Hanada T. , Ko H. J. , Yao T.
Published: March 2006

We report on the electrical properties of ZnO/GaN heterostructures and the photoresponsivity of ZnO Schottky barrier diodes for the applications of heterojunction transistors and ultraviolet photodetectors, respectivly. ZnO/GaN heterostructures exhibit a large plateau region of 6.5 V in 10 kHz capacitance‐voltage curves. Moreover, it is found that a high electron density of ∼1018 cm–3 is accumulated at the heterointerface in depth profile. ZnO Schottky barrier diodes show a rapid increase of photocurrent of ∼102 A at the long‐wavelength cutoff of 390 nm with maitaining stable diode characteristics. And, it is observed that ZnO Schottky barrier diodes respond to photosignal within 1 ∼ 2 msec with a time constant of 0.35 msec. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spontaneous phase condensation of CdTe exciton‐polaritons
Authors: Kasprzak J. , Richard M. , André R. , Romestain† R. , Malpuech G. , Kavokin A. , Si Dang Le
Published: March 2006

The cover picture of this issue of physica status solidi (c) has been taken from the article [1].
Trichopus zeylanicus combats fatigue without amphetamine‐mimetic activity
Authors: Tharakan Binu , Dhanasekaran Muralikrishnan , Brown‐Borg Holly M. , Manyam Bala V.
Published: March 2006

Chronic fatigue is a complex and little understood symptom for which there is no safe and effective pharmacotherapy. The present study was conducted to investigate the effectiveness of Trichopus zeylanicus whole plant powder on fatigue in young Sprague Dawley rats, and aged normal and long‐living mutant Ames dwarf mice. Fatigue was evaluated by subjecting the animals to a forced swim test. Trichopus zeylanicus (250 and 500 mg/kg) treated young Sprague‐Dawley rats resisted fatigue at a significant level (p < 0.005) compared with controls by an extended swim time in the forced swim test. Oral Trichopus zeylanicus (500 mg/kg) treatment for 2 weeks significantly increased the mobility time in the aged mutant (p < 0.05) and normal mice (p < 0.01) and significantly increased the swim time in the forced swim test in the aged normal mice (p < 0.05). Amphetamine‐mimetic activity in Trichopus zeylanicus was excluded by suitable tests. These results show that Trichopus zeylanicus whole plant powder has anti‐fatigue effects in young Sprague‐Dawley rats and aged normal and mutant Ames dwarf mice providing scientific evidence for the Kani tribal practice in India. Copyright © 2006 John Wiley & Sons, Ltd.
Absorption, resonance, and near‐resonance Raman studies of the tetracyanoquinodimethane neutral and its monoanion in terms of density functional theory and complete active space self‐consistent field methods
Authors: Makowski Marcin , Pawlikowski Marek T.
Published: March 2006

The electronic structure of the 11B1u and 12B3u excited electronic states of the tetracyanoquinodimethane (TCNQ) neutral and its charged derivative are studied within the framework of complete active space self‐consistent field (CASSCF) and Becke's three‐parameter hybrid method with Lee–Yang–Parr correlation functional (B3LYP) methods applied to the level aug‐cc‐p‐VDZ basis set. Both CASSCF/aug‐cc‐p‐VDZ and B3LYP/aug‐cc‐p‐VDZ treatments provide the ground‐state and the excited state geometries; these are then used to assess the Franck–Condon (FC) parameters in the 11B1u state of the neutral TCNQ and in the 12B3u state of the TCNQ monoanion. The quality of numerical results is then tested on the base of available experimental near‐resonance and resonance Raman data. The studies are performed in terms of the vibronic model, which takes both FC and mode‐mixing (Dushinsky) effects into account. This somewhat simplified vibronic model leads to very good agreement between the theory and the Raman experiments concerning both neutral TCNQ and its monoanion. In particular, the calculated excitation profiles of the ν2 = 2215 cm−1, ν4 = 1389 cm−1, ν5 = 1195 cm−1, and ν9 = 336 cm−1 fundamentals are shown to be in excellent agreement with those for the TCNQ monoanion. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Separation and measurement of flame‐formed high molecular weight polycyclic aromatic hydrocarbons by size‐exclusion chromatography and laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Apicella B. , Millan M. , Herod A. A. , Carpentieri A. , Pucci P. , Ciajolo A.
Published: March 2006

The partial contribution of polycyclic aromatic hydrocarbons (PAH), capable of being detected by gas chromatography (GC‐PAH), both to the total mass of the extractable organic fraction of flame‐formed carbon particulates and to its UV‐visible absorption and fluorescence spectra, has been determined by previous work. This contribution indicates the presence of PAH of molecular weight (MW) greater than 400 Da not accessible to conventional analysis. The detection of species in this higher MW range is important for both their potential toxicology and their possible role in soot formation. In the present work extracts of soots have been analyzed by linear mode laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF‐MS) to extend the MW range that can be analyzed beyond the GC‐PAH. The results have been compared with both analysis by reflector mode LDI‐TOF‐MS and the MW evaluation obtained by SEC analysis, as the shortcomings and advantages of both techniques appear to be complementary. Matching the results from the two techniques could give interesting insights in the molecular mass range between GC‐PAH and the first soot particles (of mass > 2000 Da). Mass spectra in this molecular mass range have been obtained with a main ion sequence spacing of 24 Th and a minor ion sequence also with a spacing of 24 Th but off‐set by 12 Th with respect to the main sequence. The two ion progressions have been interpreted by attributing the predominant peaks mainly to PAH with even‐carbon numbers and the smaller ones to cyclopenta‐fused ring PAH. These distributions indicate the occurrence of two competitive mechanisms in the growth of PAH and soot nucleation, i.e. the addition of acetylene (HACA mechanism) and the incorporation of pentagons by large polycyclic aromatic molecules into their aromatic bonding network. Copyright © 2006 John Wiley & Sons, Ltd.
The role of stable isotopes in human identification: a longitudinal study into the variability of isotopic signals in human hair and nails
Authors: Fraser I. , Meier‐Augenstein W. , Kalin R. M.
Published: March 2006

Recent natural catastrophes with large‐scale loss of life have demonstrated the need for a new technique to provide information for disaster victim identification when DNA methods fail to yield the identification of an individual, or in other situations where authorities need to determine the recent geographical life history of people. The latter may be in relation to the identification of individuals detained on suspicion of terrorism or in relation to people‐trafficking or smuggling. One proposed solution is the use of stable isotope profiling (SIP) using isotope ratio mass spectrometry (IRMS). Exploiting the link between the isotopic signal of dietary components and the isotopic composition of body tissue, the aim of this study was to refine a non‐invasive method of analysing human material such as scalp hair and fingernails using SIP and to assess the degree of natural variability in these profiles. Scalp hair and fingernail samples were collected from British and non‐British volunteers at Queen's University Belfast every 2 weeks for a minimum of 8 months. Samples were analysed using IRMS to determine their isotopic composition for 13C, 15N, 2H and 18O. The results of this longitudinal study yielded information on the natural variability of the isotopic composition of these tissues. The data demonstrate the relatively low degree of natural variation in the 13C/15N isotopic abundance of scalp hair and fingernails whilst greater variations were recorded in the hydrogen and oxygen values of the same samples. The 15N and 18O values of nail are noticeably more variable than that of scalp hair from the same subject. A hypothesis explaining this trend is put forward based on the faster rate of formation of hair than of nails. This means that there is less time for the compounds forming hair to be affected by biochemical processes that could alter their isotopic signature. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of phthalates in milk and milk products by liquid chromatography/tandem mass spectrometry
Authors: Sørensen Lambert K.
Published: March 2006

A liquid chromatographic/tandem mass spectrometric method using pneumatically assisted electrospray ionisation (LC/ESI‐MS/MS) was developed for determination of dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di‐2‐ethylhexyl phthalate (DEHP), di‐‘isononyl’ phthalate (DINP) and di‐‘isodecyl’ phthalate (DIDP) in milk and milk products including infant formulas. The phthalates were extracted by a mixture of tert‐butyl methyl ether and hexane from liquid samples. DBP, BBP and DEHP were removed from fats by liquid/liquid extraction into acetonitrile while DINP and DIDP were cleaned up on deactivated silica. The phthalates were detected in positive ion mode after separation on a reversed‐phase C5 analytical column. Two transition products were monitored for each compound. The detection limits related to the transition products of lowest abundance were in the range 5–9 µg/kg. Copyright © 2006 John Wiley & Sons, Ltd.
Evaluation of a surface‐sampling probe electrospray mass spectrometry system for the analysis of surface‐deposited and affinity‐captured proteins
Authors: Van Berkel Gary J. , Ford Michael J. , Doktycz Mitchel J. , Kennel Stephen J.
Published: March 2006

A combined self‐aspirating electrospray emitter/surfacing‐sampling probe coupled with an ion trap mass spectrometer was used to sample and mass analyze proteins from surfaces. The sampling probe mass spectrometer system was used to sample and detect lysozyme that had been deposited onto a glass slide using a piezoelectric spotter or murine gamma‐interferon affinity captured on a glass slide using surface‐immobilized anti‐gamma‐interferon antibody. The detection level for surface‐deposited lysozyme (spot size ≤200 µm) was approximately 1.0 fmol (∼100 fmol/mm2) as determined from the ability to measure accurately the protein molecular mass from the mass spectrum acquired by sampling the deposit. These detection limits may be sufficient for certain applications in which protein fractions from a separation method are collected onto a surface. Radiolabeled proteins were used to quantify the surface density of immobilized antibody and the efficiency of capture of the gamma‐interferon on glass and higher surface area ceramic supports. The capture density of gamma‐interferon at surface saturation ranged from about 23 to 50 fmol/mm2 depending on the capture surface. Nonetheless, mass spectrometric detection of affinity capture protein was successful in some cases, but the results were not reproducible. Thus, improvement of the sampling system, ionization efficiency and/or capture density will be necessary for practical sampling of affinity‐captured proteins. The means to accomplish improved sampling system detection limits and to increase the absolute amounts of protein captured per unit area are discussed. Published in 2006 by John Wiley & Sons, Ltd.
Isotopic pattern and accurate mass determination in urine drug screening by liquid chromatography/time‐of‐flight mass spectrometry
Authors: Ojanperä Suvi , Pelander Anna , Pelzing Matthias , Krebs Ilmari , Vuori Erkki , Ojanperä Ilkka
Published: March 2006

An efficient method was developed for toxicological drug screening in urine by liquid chromatography coupled with electrospray ionization time‐of‐flight mass spectrometry. The method relies on a large target database of exact monoisotopic masses representing the elemental formulae of reference drugs and their metabolites. Mass spectral identification is based on matching measured accurate mass and isotopic pattern (SigmaFit™) of a sample component with those in the database. Data post‐processing software was developed for automated reporting of findings in an easily interpretable form. The mean and median of SigmaFit™ for true‐positive findings were 0.0066 and 0.0051, respectively. The mean and median of mass error absolute values for true‐positive findings were 2.51 and 2.17 ppm, respectively, corresponding to 0.65 and 0.60 mTh. For routine screening practice, a SigmaFit™ tolerance of 0.03 and a mass tolerance of 10 ppm were chosen. Ion abundance differences from urine extracts did not affect the accuracy of the automatically acquired SigmaFit™ or mass values. The results show that isotopic pattern matching by SigmaFit™ is a powerful means of identification in addition to accurate mass measurement. Copyright © 2006 John Wiley & Sons, Ltd.
A tool for converting Linux device drivers into Solaris compatible binaries
Authors: McIlwain Sean , Miller Barton P.
Published: March 2006

The Linux operating system is quickly becoming a standard, attracting a wide user community and supporting a broad variety of applications and devices. Other vendors, such as Sun, have provided Linux‐compatible system call interfaces to their kernels, but are constrained by the lack of device support. To address this problem, we present a system (called PITS) to build device drivers, in this case for Solaris x86, from Linux source code. To accomplish this goal, we designed tools and Linux kernel emulation code to handle the myriad incompatibilities. These incompatibilities require the ability to resolve symbol conflicts, emulate internal Linux kernel data structures, handle module initialization, and generate module dependencies. With our method, we show that converting Linux device drivers is possible, but has a few technical difficulties. Issues arise with sparse documentation, external user interfaces, and modular driver implementations. There are also fundamental differences between the two operating systems, such as interrupt and DMA handling. We describe each of these issues and their current solutions to build a functional driver in the Solaris environment. Using the IOzone file system benchmark, we also demonstrate comparable performance between our generated SCSI driver set and their corresponding native counterparts. Copyright © 2006 John Wiley & Sons, Ltd.
Distribution and persistence as aspects
Authors: Soares Sérgio , Borba Paulo , Laureano Eduardo
Published: March 2006

This paper reports our experience using AspectJ, a general‐purpose aspect‐oriented extension to Java, to implement distribution and persistence concerns in a Web‐based information system. This system was originally implemented in Java and restructured with AspectJ. Our main contribution is to show that AspectJ is useful for implementing several persistence and distribution concerns in the considered application, but also in similar applications. We have also identified interferences between the implemented aspects and a few drawbacks in the language, so we suggest some minor language modifications that could significantly improve similar implementations. Despite those problems, we argue that the AspectJ implementation is superior to the pure Java implementation. Some of the aspects implemented in our experiment are abstract and constitute a simple aspect framework. The other aspects are application specific but we suggest that different implementations might follow the same aspect patterns. The framework and the patterns allow us to propose architecture‐specific guidelines that provide practical advice for both restructuring and implementing certain kinds of persistent and distributed applications with AspectJ. Copyright © 2006 John Wiley & Sons, Ltd.
Experiment on and analysis of mobile content transformation using XSLT
Authors: Ishikawa Norihiro , Suzuki Hideharu , Ueno Hidetoshi , Gotoh Tetsuya
Published: March 2006

Much attention is being paid to the services that are accessed via the Internet from mobile phones and PDAs. For such mobile Internet services, the WAP Forum issued the WAP 2.0 standard based on IETF/W3C standards. WAP 2.0 adopted the subset of eXtensible HyperText Markup Language (XHTML) and Cascading Style Sheets (CSS) standardized by World Wide Web Consortium (W3C), as its markup language. The i‐mode service in Japan was launched in February 1999, and has acquired over 40 million users, as of January 2004. The markup language adopted in the i‐mode service is called i‐mode HTML, and was designed around Compact HTML. To ease the migration from i‐mode HTML to the WAP 2.0 markup language, the functional compatibility of the languages should be assured. To this end, we proposed functions unique to i‐mode HTML to the WAP Forum. The WAP Forum accepted all of our proposals. For making the migration more cost‐effective, software tools that support the transformation of i‐mode HTML content to the WAP 2.0 equivalents must be established. There are two approaches to content transformation: software‐based and rule‐based. Since the software‐based approach has some drawbacks such as a lack of extensibility and a lack of accountability, we have taken the rule‐based approach. We focused on eXtensible Stylesheet Language Transformation (XSLT) as the content transformation technique, because XSLT has been standardized by W3C for rule‐based transformation between XML contents. To technically verify the applicability of XSLT for content transformation from i‐mode HTML to the WAP 2.0 markup language, we performed an extensive XSLT transformation experiment using existing i‐mode service contents. In this paper, we describe content transformation using XSLT, overview the content transformation system, and analyze the results of the content transformation experiment. Copyright © 2006 John Wiley & Sons, Ltd.
Socioscience and ethics in science classrooms: Teacher perspectives and strategies
Authors: Sadler Troy D. , Amirshokoohi Aidin , Kazempour Mahsa , Allspaw Kathleen M.
Published: March 2006

This study explored teacher perspectives on the use of socioscientific issues (SSI) and on dealing with ethics in the context of science instruction. Twenty‐two middle and high school science teachers from three US states participated in semi‐structured interviews, and researchers employed inductive analyses to explore emergent patterns relative to the following two questions. (1) How do science teachers conceptualize the place of ethics in science and science education? (2) How do science teachers handle topics with ethical implications and expression of their own values in their classrooms? Profiles were developed to capture the views and reported practices, relative to the place of ethics in science and science classrooms, of participants. Profile A comprising teachers who embraced the notion of infusing science curricula with SSI and cited examples of using controversial topics in their classes. Profile B participants supported SSI curricula in theory but reported significant constraints which prohibited them from actualizing these goals. Profile C described teachers who were non‐committal with respect to focusing instruction on SSI and ethics. Profile D was based on the position that science and science education should be value‐free. Profile E transcended the question of ethics in science education; these teachers felt very strongly that all education should contribute to their students' ethical development. Participants also expressed a wide range of perspectives regarding the expression of their own values in the classroom. Implications of this research for science education are discussed. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 353–376, 2006
Primary observations on rutting behavior of the captive red goral
Authors: Xie Yan
Published: March 2006

The rutting behavior of the red goral (Naemorhedus cranbrooki) was studied at the Breeding Center of Shanghai Zoo from September 16–November 21, 2004. Twenty‐three qualitatively distinct behavior patterns was observed. Males showed a more extensive repertoire (18 patterns, 15 carried out only by males) than did females (10 patterns, 6 carried out only by females). Smelling and licking behavior was used most by males, whereas escape was used most by females. Zoo Biol 0:1–7, 2006. © 2006 Wiley‐Liss, Inc.
Urinary cortisol sampling: a non‐invasive technique for examining cortisol concentrations in the Weddell seal, Leptonychotes weddellii
Authors: Constable Sophie , Parslow Arana , Dutton Geoff , Rogers Tracey , Hogg Carolyn
Published: March 2006

This study investigated the feasibility and validity of using non‐invasively collected ice urine samples to measure cortisol concentrations in Weddell seals. Radio‐immunoassays were used to determine urinary cortisol, and spectrophotometric assay was used to determine creatinine concentrations. This allowed for urinary cortisol/creatinine ratios (UCCR) to be compared between pure urine and urine collected from the ice. Urinary cortisol/creatinine ratios values of ice urine proved an effective method of studying cortisol concentrations in Weddell seals as there was no difference between pure urine and ice urine UCCR values. There were no inter‐sexual or age‐related differences in UCCR values in either pure or ice urine. Zoo Biol 0:1–8, 2006. © 2006 Wiley‐Liss, Inc.
A test for top‐down cascade in a detritus‐based food web by litter‐dwelling web spiders
Authors: Miyashita Tadashi , Niwa Shigeru
Published: March 2006

A top‐down cascade in detritus‐based food webs has the potential to alter ecosystem functioning but its prevalence in terrestrial systems remains unclear. We manipulated the density of the dominant web spiderNeriene brongersmaifor 1.5 years to see whether the cascading effect would propagate down to the litter decomposition rate in the forest‐floor of a Japanese cedar forest. Decreasing spider abundance increased collembolan density, but it did not change the biomass of microorganisms or the litter decomposition rate. We propose possible explanations for the absence of a top‐down cascade and discuss the difficulty in generalizing the presence and absence of a cascading effect in soil ecosystems.
Imaging of hyperalgesia in rats by functional MRI
Authors: Hess Andreas , Sergejeva Marina , Budinsky Lubos , Zeilhofer Hanns Ulrich , Brune Kay
Published: March 2006

Cerebral activation in response to sequences of temperature boosts at the hindpaw was observed in functional magnetic resonance imaging (fMRI) experiments in isoflurane anesthetized rats. Cingulate, retrosplenial, sensory‐motor and insular cortex, medial and lateral posterior thalamic nuclei, pretectal area, hypothalamus and periaqueductal gray were the most consistently, often bilaterally activated regions. With the same experimental paradigm, activity changes in the brain following subcutaneous zymosan injection into one hindpaw were detected. These changes developed over time (up to 4 h) in parallel with the temporal development of hyperalgesia shown by a modified Hargreaves test, thus reflecting processes of peripheral and central sensitization. When the heat stimuli were applied to the inflamed paw, the hyperalgesia manifested itself as a volume increase of the activated areas and/or an enhanced functional blood oxygenation level dependent (BOLD) signal in all the above‐mentioned brain regions. Enhanced BOLD signals were also observed in response to stimulation of the contralateral non‐injected paw. They were significant in higher associative regions and more pronounced in output‐related than in input‐related brain structures. This indicates additional sensitization processes in the brain, which we named cerebral sensitization.

Long lasting zymosan‐induced hyperalgesia could be monitored with high resolution fMRI in rats under isoflurane anaesthesia. This technique may provide an effective method for testing new analgesics and studying structure specific pain processing.
GABP complex regulates transcription of eIF6 (p27BBP), an essential trans‐acting factor in ribosome biogenesis
Authors: Donadini Alessandra , Giacopelli Francesca , Ravazzolo Roberto , Gandin Valentina , Marchisio Pier Carlo , Biffo Stefano
Published: March 2006

Eukaryotic initiation factor 6 (eIF6, alias p27BBP) is required for the biogenesis of 60S ribosomal subunits. eIF6 expression levels are tightly regulated in vivo, where they correlate with cellular growth. We analyzed how transcriptional regulation of eIF6 is achieved. We show that the human eIF6 promoter contains consensus sites for the GABP (GA‐binding protein) transcription factor complex. Functional analysis of GABP consensus sequences by point mutations, EMSA (electrophoretic mobility shift assay) and a dominant negative mutant indicates that GABP is essential for eIF6 promoter activity. These data strengthen the hypothesis that GABP is a global regulator of ribosome synthesis.
Identification and characterization of a G‐protein regulatory motif in WAVE1
Authors: Song Kyoung Seob , Peterson Yuri K. , Freidman Andrew , Blumer Joe B. , Sato Motohiko , Lanier S.M.
Published: March 2006

The G‐protein regulatory (GPR) motif is a ∼25 amino acid sequence that stabilizes the GDP‐bound conformation of Giα. To identify additional GPR motifs, we expanded a motif‐based search strategy and identified an additional 4 mammalian proteins (WAVE1–3, rat GHRH) and 10 plant proteins with candidate GPR motifs. The WAVE1 GPR peptide inhibited GTPγS binding to purified G‐protein. Endogenous Giα and WAVE1 coimmunoprecipitated from brain lysates. A WAVE1–G‐protein complex was also observed following transfection of COS7 cells with Giα3 and WAVE1. The docking of Giα within a WAVE1 scaffolding complex may facilitate dynamic cycling and/or targeting for efficient and localized control of actin polymerization.
Tuning up inflammation: How DNA sequence and chromatin organization control the induction of inflammatory genes by NF‐κB
Authors: Natoli Gioacchino
Published: March 2006

NF‐κB is a collective name given to a family of ubiquitous transcription factors (TFs) activated in response to inflammatory stimuli and environmental stressors, and required for the activation of many crucial inflammatory and immune response genes. NF‐κB is activated by degradation of its cytoplasmic anchors, the IκBs, and subsequent nuclear translocation and accumulation. Once entered in the nucleus NF‐κB activates transcription of hundreds of genes; however, each inflammatory gene must be expressed and turned off with peculiar kinetics that suit its specific function. Chromatin organization plays a major role in controlling the kinetics of NF‐κB recruitment to target genes and it represents an integration point mediating TF cooperativity.
The Moberg Deltoid-Triceps Replacement and Key-Pinch Operations in Quadriplegia: Preliminary Experiences
Authors: BRYAN RICHARD S.
Published: March 2006

The use of the tendons of the lateral four extensors of the toes in order to transfer the pull of the posterior deltoid to extend the elbow is successful in the OCu:2 quadriplegic patient. The Moberg operation for key pinch in its various modifications also improves the function of these patients and is well received by them. The necessity for prolonged protection (three months) and for simplicity in surgical procedures in these patients is illustrated in seven patients.
The Use of the Key Grip Procedure for Improving Hand Function in Quadriplegia
Authors: NEWMAN J. H.
Published: March 2006

Reconstruction of the quadriplegic hand can give marked functional improvement. In 1975 the key grip procedure was introduced on the Spinal Injuries Unit at Rancho Los Amigos Hospital. Twenty of the first twenty-four cases operated on have obtained a useful improvement, and the reasons for the four failures are readily seen. In correctly selected cases the key grip procedure is of benefit to the patient and complications are relatively minor.
Trigger Finger Following Partial Flexor Tendon Laceration
Authors: BILOS Z. JOHN , HUI PETER W. T. , STAMELOS SPIROS
Published: March 2006

An uncommon cause of trigger finger, caused by partial laceration of superficialis flexor tendon is illustrated in two patients.
Functional Disability in the Rheumatoid Hand
Authors: HARVEY KEMBLE J. V.
Published: March 2006

The investigation of sixty-one rheumatoid patients relates their hand function to measured hand deformity. Certain deformities are related to a reduction in function; others are not. The dominant hand, used more frequently, deteriorates more quickly than the non-dominant. The benefit on hand function of synovectomy is limited in duration and should be accompanied by some procedure to defer or correct deformity.

Study of the metacarpophalangeal joints by radiography and at operation shows that degeneration starts where the metacarpal head first loses articulation with the base of the phalanx, and spreads out from there across the metacarpal head as deformity increases.