bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the GaN‐rich side of GaNP grown by metal‐organic chemical vapor deposition
Authors: Tsuda Yuhzoh , Mouri Hirokazu , Araki Masahiro , Ueta Yoshihiro , Yuasa Takayuki , Taneya Mototaka 
Published: November 2003

AbstractWe have investigated the growth of the GaN‐rich side of GaNP films by metalorganic chemical vapor deposition (MOCVD). The GaNP samples were mainly analysed by using X‐ray diffraction (XRD) and Auger electron spectroscopy (AES). From the XRD measurement, we have found that the c‐axial lattice constant and the a‐axial lattice constant of our GaNP were smaller than those of GaN. Moreover, we have confirmed that these lattice constants decreased with increasing PH3 flow rate. According to the AES analysis, the nitrogen concentration in GaNP hardly changed along with increasing the PH3 flow rate, but the gallium concentration tended to decrease. This fact implies that a phosphorus atom would be replaced with not a nitrogen atom but a gallium atom on III‐group site. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Giant second‐harmonic generation due to quasi‐phase matching in a one‐dimensional GaN photonic crystal
Authors: Torres J. , Coquillat D. , Legros R. , Lascaray J. P. , Ruffenach S. , Briot O. , Aulombard R. L. , Peyrade D. , Chen Y. , Le Vassor d'Yerville M. , Centeno E. , Cassagne D. , Albert J. P. 
Published: November 2003

AbstractWe have demonstrated the giant enhancement of second‐harmonic generation in a one‐dimensional GaN photonic crystal structure caused by the simultaneous achievement of strong fundamental field confinement and quasi‐phase matching conditions. We have firstly measured the linear dispersive properties of the resonant modes for various azimuthal directions to predict the quasi‐phase matching conditions. The theory based on a rigorous scattering matrix method has provided a good description of the equi‐frequency surfaces. We have then shown that the equi‐frequency surfaces may be used to identify the angular situations for which the quasi‐phase matching conditions can be satisfied. The SHG enhancement achieved due to the double resonance was 5000 times greater than for the unpatterned GaN layer. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton localization in InGaN/GaN single quantum well structures
Authors: Graham D. M. , Vala A. Soltani , Dawson P. , Godfrey M. J. , Kappers M. J. , Smeeton T. M. , Barnard J. S. , Humphreys C. J. , Thrush E. J. 
Published: November 2003

AbstractWe have performed a detailed investigation of the low temperature (T = 6 K) photoluminescence spectra and recombination lifetimes of localized excitons in a set of InGaN/GaN single quantum wells in which the indium fraction in the quantum well was varied. We found that with increasing indium fraction the photoluminescence peak emission moved to lower energy and the intensities of the phonon replicas relative to the zero‐phonon line increased. From a multi‐Gaussian fit of the experimental data, we extracted the Huang–Rhys factor (S), a measure of the strength of the exciton coupling with LO‐phonons. By comparing experimental S factors with the results of a theoretical model, we found that the excitons localize on a length scale of ∼2 nm in our samples. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoreflectance studiesof N‐ and Ga‐face AlGaN/GaN heterostructures confininga polarisation induced 2DEG
Authors: Winzer A. T. , Goldhahn R. , Buchheim C. , Ambacher O. , Link A. , Stutzmann M. , Smorchkova Y. , Mishra U. K. , Speck J. S. 
Published: November 2003

AbstractPhotoreflectance measurements have been carried out in order to determine the electric field strength F within the topmost layers of Ga‐face polarity AlxGa1−xN/GaN and N‐face polarity GaN/AlxGa1−xN/GaN heterostructures containing high‐mobile polarisation induced 2DEGs. For both types of samples F decreased from 400 kV/cm at room temperature up to 200 kV/cm when cooling down the structure to T = 5 K. Our results strongly emphasise the existence of surface donor and surface acceptor states of the Ga‐ and N‐face samples, respectively. The temperature dependence of F is explained by the change of the piezoelectric and spontaneous polarization. From self‐consistent conduction band calculations the bare surface potential was obtained. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measurement of optical nonlinearities from intersubband transitions in GaN/AlGaN quantum wells at 1.5 μm
Authors: Chen Gang , Rapaport R. , Mitrofanov O. , Gmachl C. , Ng H. M. 
Published: November 2003

AbstractWe measured the resonant nonlinear optical absorption and refraction due to intersubband transitions in GaN/AlGaN multiple quantum well structures at 1.5 μm. The measured values are much smaller than that predicted by theoretical studies. This is attributed to a larger than expected dephasing of excited electrons. At high excitation intensity, the absorption can be saturated. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Angular dependence of the in‐plane polarization anisotropy in the absorption coefficient of strained M‐plane GaN films on γ‐LiAlO2
Authors: Misra Pranob , Sun Y. J. , Brandt O. , Grahn H. T. 
Published: November 2003

AbstractWe investigate the in‐plane polarization properties of GaN films grown by plasma‐assisted molecular‐beam epitaxy on LiAlO2(100). Due to the crystal symmetry of LiAlO2(100), GaN films can be realized in a nonpolar (M‐plane) configuration, i.e., the c‐axis of the wurtzite unit cell lies in the growth plane. For strained M‐plane GaN films, the band structure of the valence band changes in such a way that the optical transmittance is completely linearly polarized for two orthogonal in‐plane directions, where one of these directions is parallel to the c‐axis of the GaN film. The transmittance for an arbitrary in‐plane polarization angle can be described as a linear combination of the transmittance for two orthogonal polarization, one of which is parallel to the c‐axis. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence and Raman study of hexagonal InN and In‐rich InGaN alloys
Authors: Davydov V. Yu. , Klochikhin A. A. , Emtsev V. V. , Smirnov A. N. , Goncharuk I. N. , Sakharov A. V. , Kurdyukov D. A. , Baidakova M. V. , Vekshin V. A. , Ivanov S. V. , Aderhold J. , Graul J. , Hashimoto A. , Yamamoto A. 
Published: November 2003

AbstractWe present results of a detailed study of X‐ray, photoluminescence, and Raman measurements of hexagonal InN, In‐rich InxGa1−xN (0.36 < x < 1) alloys, and InN samples annealed in oxygen. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Localized biexcitons in AlxGa1−xN ternary alloy epitaxial layers
Authors: Yamada Y. , Sasaki C. , Ueki Y. , Taguchi T. , Tanaka S. , Nakagawa Y. 
Published: November 2003

AbstractExcitonic optical properties of AlxGa1−xN ternary alloy epitaxial layers have been studied by means of photoluminescence (PL), time‐resolved PL, and PL excitation (PLE) spectroscopy. The luminescence line due to radiative recombination of biexcitons was clearly observed in an Al0.08Ga0.92N epitaxial layer. The PL decay time of excitons and biexcitons was estimated to be 350 and 210 ps, respectively. PLE spectroscopy of biexcitons enabled us to observe a two‐photon absorption process of biexcitons. On the basis of the energy separation between exciton resonance and two‐photon biexciton resonance, the binding energy of biexcitons in Al0.08Ga0.92N was estimated to be 15 ± 2 meV. This value was approximately 2.5 times as large as the binding energy of biexcitons in GaN. This value was also found to be comparable to the observed energy separation between the exciton luminescence and the biexciton luminescence, which indicated the strong localization of biexcitons. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of MOVPE‐grown GaN layers on GaAs (111)B with a cubic‐GaN (111) epitaxial intermediate layer
Authors: Sanorpim S. , Takuma E. , Katayama R. , Ichinose H. , Onabe K. , Shiraki Y. 
Published: November 2003

AbstractWe have proposed the use of cubic‐GaN (c‐GaN) as an intermediate layer for the metalorganic vapor phase epitaxy (MOVPE) growth of hexagonal‐GaN (h‐GaN) on GaAs (111)B substrates. Insertion of the c‐GaN layer at the h‐GaN (0001)/GaAs (111) interface significantly improves the crystallinity of the h‐GaN layer. Although, we have used [111]‐oriented c‐GaN layer so far, the lattice‐mismatch between h‐GaN (0001) and c‐GaN (111) is expected to be less than 0.1%, which is much smaller than that for the other commonly used substrate materials. Furthermore, the c‐GaN layer was grown at a relatively low growth temperature (Tg = 600 °C) to prevent the GaAs substrate from thermal decomposition and to provide a strain relief template layer. This technique enables us to succeed in obtaining nearly strain free h‐GaN layers on GaAs (111)B substrates. In this report, the relationship between the nature of the c‐GaN intermediate layer and the cubic‐to‐hexagonal structural transition machanisms are discussed. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Narrow bandgap group III‐nitride alloys
Authors: Wu J. , Walukiewicz W. , Yu K. M. , Ager III J. W. , Haller E. E. , Lu Hai , Schaff William J. 
Published: November 2003

AbstractHigh‐quality wurtzite In‐rich In1−xGaxN (0 ≤ x ≤ 0.5) and In1−yAlyN films (0 ≤ y ≤ 0.25) were grown on sapphire substrates by molecular‐beam epitaxy. Optical absorption, photoluminescence and photomodulated reflectance measurements demonstrate that the fundamental bandgap for InN is only about 0.7 eV. The free electron effective mass is found to vary with free electron concentration, the consequence of a strongly non‐parabolic conduction band caused by the k · p interaction with the valence bands across the narrow bandgap. The bandgap gradually increases with increasing Ga or Al content in In1−xGaxN or In1−yAlyN alloys. The composition dependencies of the bandgaps are well described by bowing parameters of 1.4 eV for In1−xGaxN and 3.0 eV for In1−yAlyN. The direct gaps of the group III‐nitride alloy system cover a very broad spectral range from the near‐infrared in InN to deep‐ultraviolet in AlN. This offers unique opportunities for the use of these alloys in a wide range of optoelectronic and photovoltaic devices. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarization‐induced surface band bendings of GaN films studied by synchrotron radiation photoemission spectroscopy
Authors: Jang Ho Won , Ihm Kyu Wook , Kang Tai‐Hee , Lee Jung‐Hee , Lee Jong‐Lam 
Published: November 2003

AbstractThe change in the surface band bandings of GaN films with crystal polarity and strain was investigated using synchrotron radiation photoemission spectroscopy. The Ga‐face GaN sample showed larger surface band bending than the N‐face one by 1.4 eV due to spontaneous polarization‐induced sheet charges at the surface, resulting in a higher Schottky barrier height of a Pt contact. For both n‐type and p‐type GaN, the shift of the surface Fermi level with longitudinal tensile strain (∼4 × 10−3) is negligible, while that with compressive strain (∼3 × 10−3) is significant. This could be attributable to combined effects of piezoelectric polarization‐induced sheet charges and the change of bandgap energy with the strains near the surface region. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of Amylose in the Maintenance of the Configuration of Rice Starch Granules
Authors: Seguchi Masaharu , Hayashi Miho , Suzuki Yasuhiro , Sano Yoshio , Hirano Hiro‐Yuki 
Published: November 2003

AbstractAmylose contents in 39 strains of rice starch, including waxy starch, low amylose containing starch, and non‐waxy starch, were measured. Seguchi et al. [1] reported that waxy wheat starch exhibits a ghost appearance by staining and swelling with 25% KI/10%I2 solution at 25 °C. We subjected the 39 rice strains to staining in the same manner. We found that the relative ghost area (%) in a rice starch, which is a measure of granule swelling in 25%KI/10%I2 solution, , is related to its amylose content (r = ‐0.78). As the relative ghost area (%) of the rice starch increased rapidly when the amylose content decreased below 5%, we concluded that at least 5% of amylose is required to maintain the structure of rice starch granules. Furthermore, the red‐brown central region in ghostly appearing granules decreases with amylose level and the surrounding light brown region increases. When the starch does not contain amylose, the ghost is entirely light brown. The decrease in the area of the red‐brown central region with decreasing amylose content suggests that amylose is concentrated in the red‐brown central region of the ghost.
Crystallinity and Pasting Properties of Freeze‐Thawed High Amylose Maize Starch
Authors: Jeong Hyo‐Young , Lim Seung‐Taik 
Published: November 2003

AbstractNative and defatted high amylose (about 70%) maize starch gels were freeze‐dried or repeatedly freeze‐thawed, and the effects of the treatments on the crystallinity, pasting viscosity, and resistance to digestive enzymes of the dried starch were examined. Both native and defatted starches showed a B‐type crystal structure in the X‐ray diffractogram, but the crystallinity was decreased by repeating the freeze‐thawing cycle. In the DSC thermogram, the freeze‐thawed starches exhibited two endothermic transitions in the temperature ranges of 90—110 °C and 130—160 °C, representing amyloselipid complexes and amylose‐amylose double helix crystals, respectively. By defatting, the melting enthalpy for the amylose double helices was increased, indicating that the residual lipids inhibited the amylose crystal formation. Ice crystals in the starch gel matrix became smaller and the ice cell membrane became thinner as freeze‐thawing was repeated. The freeze‐dried or freeze‐thawed starch powders swelled to a paste by heating in water as did typical granular starch, but the setback by cooling was significantly high due to the rapid retrogradation of leached amylose. By the treatments, the resistance of the starch to digestive enzymes was also raised. The defatted starches displayed greater paste viscosity and resistance to digestive enzymes than the native starches. But the overall viscosity was decreased as the number of freeze‐thawing cycles increased.
Impregnation of Kraft Paper with Cassava‐Starch Acetate — Analysis of the Tensile Strength, Water Absorption and Water Vapor Permeability
Authors: Larotonda Fábio D. S. , Matsui Kátia S. , Paes Sabrina S. , Laurindo João Borges 
Published: November 2003

AbstractKraft paper is widely used in the manufacture of packing, but its hygroscopic properties and water vapor barrier are not suitable for the storage of dehydrated products for long periods. The objective of this work was to study the influence of the impregnation of this paper with cassava‐starch acetate (CSA, degree of substitution, DS, 1.41) and the consequent modification of tensile strength, water absorption and water vapor permeability. SEM‐micrographs were taken and experiments of water absorption, tensile strength, water vapor permeability and water sorption isotherms were carried out for original and CSA‐impregnated Kraft paper. The results obtained showed that the impregnation of the Kraft paper with CSA significantly decreases the water absorption and the water vapor permeability. Water sorption isotherms showed great differences only at high relative humidity. In relation to mechanical properties, the tensile strength of the Kraft paper increased with its impregnation by CSA. Therefore, CSA impregnation was demonstrated to be a very interesting and new alternative for the use of cassava starch to obtain waterproof paper.
Involvement of myosin in intracellular motility and cytomorphogenesis in Micrasterias
Authors: Oertel Anke , Holzinger Andreas , Lütz‐Meindl Ursula 
Published: November 2003

AbstractMyosin was detected on Western blots of Micrasterias denticulata extracts by use of antibodies from different sources. Inhibitors with different targets of the actomyosin system, such as the myosin ATPase‐blockers N‐ethylmaleimide (NEM) and 2,3‐butanedione monoxime (BDM), or the myosin light chain kinase inhibitor 1‐(5‐iodonaphthalene‐1‐sulfonyl)‐1H‐hexhydro‐1,4‐diazapine (ML7), had similar effects on intracellular motility during cell development in the green alga Micrasterias, thus pointing towards a participation of myosin in these processes. The drugs markedly altered the mode of postmitotic nuclear migration, slowed down cytoplasmic streaming, changed cell pattern development and prevented normal chloroplast distribution and spreading into the growing semicell. In addition, an increase and dilatations in ER cisternae and marked morphological changes of the Golgi system were observed by transmission electron microscopy after exposure of growing cells to BDM.Neither BDM nor ML7 exhibited any effect on the distribution or arrangement of the cortical F‐actin network nor on the F‐actin basket around the nucleus, characteristic of untreated growing Micrasterias cells (J Cell Sci 107 (1994) 1929). This is particularly interesting since BDM caused disintegration of the microtubule system co‐localized to the F‐actin cage during normal nuclear migration. Together with the fact that other microtubules not connected to the F‐actin system remained uninfluenced by BDM, this observation is evidence of an integrative function of myosin between the cytoskeleton elements.
Impact of glafenine hydrochloride on human endothelial cells and human vascular smooth muscle cells: a substance reducing proliferation, migration and extracellular matrix synthesis
Authors: Schöber Wolfgang , Tran Quoc Bao , Muringaseril Matthew , Wiskirchen Jakub , Kehlbach Rainer , Rodegerdts Enno , Wiesinger Benjamin , Claussen Claus D , Duda Stephan H 
Published: November 2003

AbstractThe aim of this study was to examine the effects of glafenine hydrochloride (a nonsteroidal anti‐inflammatory drug) on proliferation, clonogenic activity, cell‐cycle, migration, and the extracellular matrix protein tenascin of human aortic smooth muscle cells (haSMCs) and human endothelial cells (ECs) in vitro.HaSMCs and ECs were seeded in tissue culture flasks. The cells were treated for 4 days with glafenine hydrochloride (10 μM, 50 μM, 100 μM). Half of the treated groups were incubated again with glafenine hydrochloride, the other half received medium free of glafenine hydrochloride every 4 days until day 20. The growth kinetics and clonogenic activity were assessed. Cell cycle distribution was investigated by FACS, migratory ability was evaluated, and effects on extracellular matrix synthesis were assessed by immunofluorescence.Glafenine hydrochloride inhibited the proliferation and clonogenic activity of haSMCs and ECs in a dose‐dependent manner. A block in the G2/M phase and a reduction in the G1 phase occurred. The migratory ability of haSMCs was impaired in a dose‐dependent manner and the extracellular matrix protein tenascin was reduced. As glafenine hydrochloride has the ability to fully inhibit proliferation and to partially inhibit migration in haSMCs, it could be an interesting substance for further research in the field of restenosis therapy.
Women have later onset than men in schizophrenia—but only in its paranoid form. Results of the DSP project
Authors: Salokangas Raimo K.R. , Honkonen Teija , Saarinen Soile 
Published: November 2003

AbstractAccording to the literature, schizophrenia begins in men earlier than in women. It has been argued that the gender-bound age difference is due to the protective antidopaminergic effect of estrogens in women. However, the effect of gender on the age of onset may vary between different types of schizophrenias, and can also be modulated by marital status and by age at onset of illness. Comprehensive data were collected on 3306 DSM IIR schizophrenia patients, aged 15–64 years, who had been discharged from psychiatric hospitals in Finland in 1982, 1986 and 1990. The age of onset of illness (AOI) was defined by the age at the first admission (AFA). Male patients were admitted earlier than female patients, and a small second peak in women appeared at the age of 40–44. However, there were no gender differences in AFA within diagnostic subgroups, except in paranoid schizophrenia in which AFA was lower in men than in women even when marital status was taken into account. Within paranoid schizophrenia, this effect of gender was significant only in those of the patients whose AFA was higher than 30 years. It is suggested that there is no gender difference in AOI in early onset schizophrenia. In later onset, paranoid schizophrenia, the illness seems to manifest in women later than in men.
Lithium augmentation in venlafaxine non-responders: an open study
Authors: Bertschy G. , Ragama-Pardos E. , Aït-Ameur A. , Muscionico M. , Favre S. , Roth L. 
Published: November 2003

AbstractThirteen major depressive patients not responding to a 4-week venlafaxine 300 mg treatment were eligible for a 4-week open trial of lithium addition. Two patients had to stop lithium for a possible moderate serotonin syndrome and five patients became responders, including one dramatic response and two semi-rapid responses.
Gender differences and outcome in schizophrenia: a 2-year follow-up study in a large community sample
Authors: Usall J. , Ochoa S. , Araya S. , Márquez M. ,   NEDES group (Assessment Research Group in Schizophrenia)
Published: November 2003

AbstractThis study examined gender differences in the short-term (2 years) course of schizophrenia in a sample of 200 schizophrenic (DSM-IV criteria) outpatients (74 women and 126 men). Number and length of hospitalizations during the prospective follow-up were recorded. After 2 years, men were found to have more hospitalizations and longer stays than women. Among subjects who had at least one hospitalization (12 women and 38 men), men had greater length of hospitalization. In conclusion, schizophrenic women had a significantly better short-term outcome.
Clients with long-term mental disabilities in a Swedish county—conditions of life, needs of support and unmet needs of service provided by the public health and social service sectors
Authors: Jansson Lennart , Sonnander Karin , Wiesel Frits-Axel 
Published: November 2003

AbstractObjectiveThe purpose of the study was to identify and describe conditions of life and needs of support and public service for clients with a mental disability in a Swedish county population.MethodsPublic health care and social service providers identified clients and completed a questionnaire concerning the clients’ conditions of life and their special needs. A consecutively recruited sample of clients completed a similar questionnaire.ResultsTotally, 1261 clients were identified. The prevalence of clients with mental disabilities was in the urban and rural areas, 6.4/1000 inhabitants and 4.5/1000 inhabitants, respectively. The most prevalent unmet need (42.9%) was to participate in social and scheduled activities. Almost half of the group was reported to need support in activities of daily living. Clients living in urban settings more often needed support with activities of daily living (P < 0.001), whereas clients living in rural settings more often needed support with job training (P < 0.001) or finding work (P < 0.01). Clients and psychiatric care providers reported the needs of the clients in the same areas; however, clients reported a fewer number of needs than did the care providers.ConclusionsBy using both psychiatric care and social service providers, effective case findings of clients with a mental disability were possible to achieve. In general, there was high agreement between psychiatric care providers and clients regarding the clients’ number of needs of support and their unmet needs of service. However, at the individual level, the agreement between client and psychiatric care providers was lower.