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  • 1
    Digitale Medien
    Digitale Medien
    Physical and electrical characterization of Hafnium oxide and Hafnium silicate sputtered films (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 6466-6475 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Hafnium oxides and hafnium silicate films were investigated as a possible replacement for the SiO2 gate dielectric. Hafnium oxide films were formed by reactive sputtering from a single Hf oxide target in a predominantly Ar atmosphere containing small additions of oxygen. Hafnium silicates were made by adding a He-diluted silane gas for Si incorporation. By changing the silane gas flow, different Si atomic concentrations were incorporated into the Hf oxide films. Depositions were performed with the substrate held at temperatures of 22 °C and 500 °C. The chemical composition of the films was determined with nuclear techniques. Optical reflectivity was used to measure the optical band gap. The film morphology was investigated by transmission electron microscopy (TEM) and the electrical properties were measured with capacitance–voltage and current–voltage measurements using aluminum gate capacitors. TEM and electrical measurement showed that a SiO2 interfacial layer of about 3 nm formed at the Si interface due to the oxidizing sputter ambient. This precluded the growth of Hf based high-K films with small equivalent thickness. After correction for the interfacial oxide layer, the dielectric constant was found to decrease from about 21 for Hf oxide to about 4–5 for the Hafnium silicates with low Hf content (3 at. % Hf and 32 at. % Si). The optical band gap was found to increase from 5.8 eV for Hf oxide to about 7 eV for the silicate films. After annealing at 1000 °C followed by a 300 °C postmetallization anneal, negligible flat band voltage shift were measured on hafnium silicate films and good interface passivation was observed. However, leakage currents increased due to the high temperature processing. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1417991
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  • 2
    Digitale Medien
    Digitale Medien
    Modified magnetic resonance imaging score compared with orthopaedic and radiological scores for the evaluation of haemophilic arthropathy (2002)
    Oxford UK : Blackwell Science Ltd
    Haemophilia 8 (2002), S. 0 
    Details
    ISSN: 1365-2516
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Twenty-four joints (10 knees and 14 ankles), with at least one manifestation of bleeding (proven by sonographic assessment), of 15 patients with haemophilia were investigated prospectively. For magnetic resonance imaging (MRI) evaluation, the MRI scale of Nuss et al. was modified to a MRI score (max. 13 points/joint) to allow a comparison with the physical examination score (max. 12 points) and the radiological score (Pettersson score; max. 13 points). The number of joint bleeds correlated well with the degree of arthropathy P 〈 0.01). In all 16 joints with a maximum of two bleeds, no alterations were found by physical examination, or radiological and MRI assessment. Joints with three bleeds had physical examination scores between 0 and 2, Pettersson scores from 0 to 3 and MRI scores of 2. Joints with four or more bleeds had physical examination scores ranging between 3 and 7, radiological scores between 7 and 12 and MRI scores between 3 and 8. The MRI score describes initial joint alterations more precisely and earlier than other assessments, allowing a discerning estimation of the degree of arthropathy, as well as a follow-up of haemophilic arthropathy and an improvement after change of treatment. In addition, the modified MRI score seems to differentiate better between early and advanced signs of arthropathy than the MRI scale of Nuss et al.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2516.2002.00585.x
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  • 3
    Digitale Medien
    Digitale Medien
    New vacuum solutions of conformal Weyl gravity (2000)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 41 (2000), S. 3007-3015 
    Details
    ISSN: 1089-7658
    Quelle: AIP Digital Archive
    Thema: Mathematik , Physik
    Notizen: The Bach equation, i.e., the vacuum field equation following from the Lagrangian L=CijklCijkl, will be completely solved for the case that the metric is conformally related to the Cartesian product of two two-spaces; this covers the spherically and the plane symmetric space–times as special subcases. Contrary to other approaches, we make a covariant 2+2-decomposition of the field equation, and so we are able to apply results from two-dimensional gravity. Finally, some cosmological solutions will be presented and discussed. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.533287
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  • 4
    Digitale Medien
    Digitale Medien
    Self-diffusion studies of 15N in amorphous Si3BC4.3N2 ceramics with ion implantation and secondary ion mass spectrometry (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 1827-1830 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Nitrogen self-diffusion studies in amorphous precursor-derived Si3BC4.3N2 ceramics were carried out, using ion implanted stable 15N isotopes as tracers and secondary ion mass spectrometry for depth profiling. The analysis of the diffusion profiles in the range of 1500–1700 °C did not show the typical Gaussian broadening of the implantation profiles. Instead, we observed the occurrence of a high concentration region where the width of the implantation profile is nearly unchanged due to implantation damage, and a low concentration region where diffusion occurs. The experimentally determined diffusivities obey an Arrhenius behavior with an activation enthalpy of about H=7 eV and a pre-exponential factor D0 in the order of 5 m2/s which indicates a diffusion mechanism via vacancy-like defects. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1305903
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  • 5
    Digitale Medien
    Digitale Medien
    Coherent magnetization reversal of nanoparticles with crystal and shape anisotropy (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 507-513 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We discuss coherent magnetization reversal in single-domain particles with cubic or uniaxial crystal anisotropy and present the derivation and simulation of the nucleation field in the important case of particles with shape anisotropy and a random orientation of a cubic crystal anisotropy axis. We analyze the interplay of shape and crystal anisotropy as a function of crystal orientation with respect to the applied field. In addition, we present simulations for particles with uniaxial crystal anisotropy and derive the values for remanence and coercive field of an ensemble of particles from calculated hysteresis loops in each case. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1323519
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  • 6
    Digitale Medien
    Digitale Medien
    All-optical wavelength converter and switch based on electromagnetically induced transparency (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 3173-3175 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We propose a method for all-optical switching and wavelength conversion using electromagnetically induced transparency (EIT). We discuss the mechanism for the transfer of information in this scheme and determine the conditions for which N×N wavelength conversion can be realized. We compare the properties and limits of an EIT-based switch to conventional wavelength converters. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.126620
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  • 7
    Digitale Medien
    Digitale Medien
    Congenital adrenal hyperplasia and acne in male patients (2003)
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 148 (2003), S. 0 
    Details
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Summary Seborrhoea is one pathogenic factor for acne. Androgens induce sebum production, and excess androgen may provoke or aggravate acne. In women an androgen disorder is frequently suspected when acne is accompanied by hirsutism or menstrual irregularities. In men acne may be the only symptom of androgen excess. We report three male acne patients in whom hormonal screening revealed irregularities of androgen metabolism suggestive of late-onset congenital adrenal hyperplasia and who benefitted from low-dose glucocorticoids. Disorders of androgen metabolism may influence acne not only in women, but also in men, and these patients may benefit from low-dose glucocorticoid therapy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2133.2003.05369.x
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  • 8
    Digitale Medien
    Digitale Medien
    Mutations in the NOD2/CARD15 gene in Crohn's disease are associated with ileocecal resection and are a risk factor for reoperation (2004)
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 19 (2004), S. 0 
    Details
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background : Mutations within the NOD2/CARD15 gene have recently been shown to be associated with Crohn's disease.Aims : To investigate the clinical impact of the three common NOD2/CARD15 mutations in patients with Crohn's disease.Methods : We investigated the prevalence of the three common NOD2/CARD15 mutations (Arg702Trp, Gly908Arg, 3020insC) in 180 patients with Crohn's disease, 70 patients with ulcerative colitis and 97 controls. In patients with Crohn's disease, prevalence of NOD2/CARD15 mutations were correlated to clinical and demographical parameters.Results : In Crohn's disease patients, 35.6% carried at least one mutant allele of NOD2/CARD15 mutations compared with 14.3% of patients with ulcerative colitis (P = 0.006) and to 15.5% of controls (P = 0.0001). Genotype phenotype analyses revealed that NOD2/CARD15 mutations determined younger age at disease diagnosis (P = 0.03), ileal disease location (P = 0.01) and ileocecal resections (P = 0.0002). Interestingly, reoperation with resection of the anastomosis was significantly more frequent in patients with NOD2/CARD15 mutations (P = 0.01).Conclusions : Our investigations support the current hypothesis that NOD2/CARD15 mutations are associated with a phenotype of Crohn's disease with younger age at diagnosis, ileal involvement, ileocecal resections and a high risk of postoperative relapse and reoperation. NOD2/CARD15 mutations might therefore be used to identify high risk patients for relapse prevention strategies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2036.2004.01967.x
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  • 9
    Digitale Medien
    Digitale Medien
    Serum antibody reactivity against recombinant PrtC of Porphyromonas gingivalis following periodontal therapy (2003)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of periodontal research 38 (2003), S. 0 
    Details
    ISSN: 1600-0765
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Objectives:  In 34 patients with chronic periodontitis, the presence of IgA, IgG, and IgG subclass serum antibodies against recombinant PrtC (rPrtC) of Porphyromonas gingivalis was assessed by immunoblot analysis 24 months after therapy.Methods:  rPrtC was produced from P. gingivalis ATTC 33277 using the plasmid pGEX-2T. In addition, intraoral colonization with P. gingivalis was detected by PCR in subgingival plaque and swab samples from buccal mucosae, tonsils and tongue at baseline, 10 d, and 3, 6, 9, 12, 18, and 24 months.Results:  All patients were found to harbor P. gingivalis in the oral cavity at least once during the observation period. The identified antibody responses against the rPrtC of P. gingivalis were IgA (97%, i.e. 33/34 patients) and IgG (100%, i.e. 34/34), with an IgG subclass distribution of IgG2 (65%, i.e. 22/34 patients) 〉 IgG3 (47%, i.e. 16/34) 〉 IgG1 (38%, i.e. 13/34) 〉 IgG4 (29%, i.e. 10/34). Anti-rPrtC IgA and IgG antibody reactivity was found in all but one patients (anti-rPrtC IgA negative), who tested negative for P. gingivalis at all of the assessed intraoral sites for at least 6 months before sera collection. There was no association between IgG subclass reactivity against the rPrtC of P. gingivalis and progression of periodontal attachment loss.Conclusion:  The results indicated that anti-rPrtC IgA and IgG antibodies may serve as an indicator for past or present intraoral colonization with P. gingivalis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1034/j.1600-0765.2003.01405.x
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  • 10
    Digitale Medien
    Digitale Medien
    Kinematical two-dimensional multiple-diffraction intensity profiles. Application to ω–ψ scans of silicon and diamond obtained with synchrotron radiation (2001)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 34 (2001), S. 157-165 
    Details
    ISSN: 1600-5767
    Quelle: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Thema: Geologie und Paläontologie , Physik
    Notizen: In a previous paper by Rossmanith [J. Appl. Cryst. (2000), 33, 1405–1414], expressions for the calculation of multiple-diffraction patterns observed in ω–ψ scans of Bragg reflections were derived within the framework of the kinematical theory, taking into account the divergence and wavelength spread of the incident beam, as well as the mosaic structure of the crystal sample. Agreement with Cu Kα experiments was demonstrated. In this paper, it is shown that the theoretical expressions are also suitable for synchrotron radiation experiments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1107/S0021889801001352
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