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  • 1
    Digitale Medien
    Digitale Medien
    Photoluminescence studies of GaN layers grown by hydride vapor phase epitaxy (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 1692-1695 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Photoluminescence of gallium nitride (GaN) layers 7.5–870 μm thick was studied with changes in temperature and excitation intensity. These layers were grown by hydride vapor phase epitaxy on a buffer layer of aluminum nitride (AlN). The photoluminescence emission consists of the shallow-donor bound exciton at 3.471 eV and the free hole-to-electron bound to a donor (possibly a nitrogen vacancy VN or oxygen) transition at 3.40–3.433 eV. The peak position varies depending on the thickness of the GaN and AlN layers. The localized donor due to donor concentration fluctuation is attributed to the variable peak position. The observed 3.269 eV emission is attributed to a donor–acceptor pair transition. The relationship between the peak and the excitation intensity is described accurately by a theoretical description which yields Ed=32 meV and Ea=230 meV, which originate, respectively, from a silicon donor and carbon acceptor. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1337589
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  • 2
    Digitale Medien
    Digitale Medien
    Characterization of catastrophic optical damage in Al-free InGaAs/InGaP 0.98 μm high-power lasers (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 2567-2569 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Catastrophic optical damage (COD) in Al-free InGaAs/InGaP 0.98 μm lasers has been investigated using real-time electroluminescence (EL) and transmission electron microscopy (TEM). From EL images, we observed that multiple bright spots initiated from one of the facets and then propagated to the center of the cavity during the COD process. It is clarified by the TEM analysis that the propagation of bright spots resulted in 60-nm-wide Moiré fringe along the cavity and the crystalline phase of the active area became polycrystalline. Highly nonradiative polycrystalline phase of the active area is the major cause of COD failure in the Al-free 0.98 μm lasers. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.122557
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  • 3
    Digitale Medien
    Digitale Medien
    Substrate dependence on the optical properties of Al2O3 films grown by atomic layer deposition (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 3604-3606 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The atomic layer deposition technique has been applied to the growth of Al2O3 thin films on the substrates of Si(100), 100-nm-thick SiO2 covered Si(100) [SiO2/Si(100)], and 90-nm-thick TiN covered SiO2/Si(100). The growth rate of Al2O3 films was 0.19 nm/cycle and identical for all substrates employed under the surface controlled process. However, the optical properties of Al2O3 films were significantly affected by different substrates. The average interband-oscillator energy and refractive index parameter were determined to be 3.330 eV and 2.992×10−14 eV m2 for Al2O3 film grown on Si(100), while those for the film grown on SiO2/Si(100) were 4.492 eV and 2.074×10−14 eV m2, respectively. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.120454
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  • 4
    Digitale Medien
    Digitale Medien
    Stereocontrolled catalytic asymmetric reduction of ketones with oxazaborolidines derived from new chiral amino alcohols (1993)
    s.l. : American Chemical Society
    The @journal of organic chemistry 58 (1993), S. 4511-4512 
    Details
    ISSN: 1520-6904
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/jo00069a002
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  • 5
    Digitale Medien
    Digitale Medien
    Steroid Hormones and the Kidney (1981)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Physiology 43 (1981), S. 637-649 
    Details
    ISSN: 0066-4278
    Quelle: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Thema: Medizin , Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1146/annurev.ph.43.030181.003225
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  • 6
    Digitale Medien
    Digitale Medien
    Properties of WNx films and WNx/GaAs Schottky diodes prepared by ion beam assisted deposition technique (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 1134-1136 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Low energy ion beam assisted deposition (IBAD) of refractory tungsten nitride films onto GaAs is attempted for the first time. This ion beam technique provides lower process pressure, and less ion damage to substrates and films than conventional reactive sputter deposition. Schottky diode characteristics of W/ and WNx/GaAs and their thermal stability were investigated by capping the refractory films with SiO2 films and subsequent annealing at 700–900 °C for 30 min. While both tungsten and tungsten nitride contacts were stable up to 850 °C, the tungsten nitride contact showed better thermal stability and higher Schottky barrier height. The Schottky barrier heights of W/ and WN0.27/GaAs diodes annealed at 850 °C were 0.71 and 0.84 eV, respectively. These preliminary results are comparable to those of the best results reported with the conventional sputtering methods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.345759
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  • 7
    Digitale Medien
    Digitale Medien
    A stable seeding method for Porphyra pseudolinearis Ueda (Rhodophyta): developing a new species for cultivation of Porphyra in Korea (2003)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 34 (2003), S. 0 
    Details
    ISSN: 1365-2109
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2109.2003.00886.x
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  • 8
    Digitale Medien
    Digitale Medien
    Association of thromboxane A2 receptor gene polymorphism with the phenotype of acetyl salicylic acid-intolerant asthma (2005)
    Oxford, UK : Blackwell Science Ltd
    Clinical & experimental allergy 35 (2005), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background and objective The thromboxane A2 receptor (TBXA2R) is a receptor for a potent bronchoconstrictor, TBXA2 which is known to be related to bronchial asthma and myocardial infarction. TBXA2R antagonist and TBX synthase inhibitors have been found to be effective in the management of asthmatic patients. This study was aimed to evaluate whether genetic variants of TBXA2R may be related with development of acetyl salicylic acid (ASA)-intolerant asthma (AIA).Methods TBXA2R gene polymorphisms (TBXA2R+795T〉C, TBXA2R+924T〉C) were determined using a single-base extension method in 93 AIA patients compared with 172 patients with ASA-tolerant asthma (ATA) and 118 normal controls (NCs) recruited from the Korean population. HLA DPB1*0301 genotype was performed using a direct sequencing method.Results The rare C allele frequency of TBXA2R+795T〉C was significantly higher in AIA than in ATA (P=0.03) and the TBXA2R+795T〉C polymorphism was also associated with extent of percent fall in forced expiratory volume in 1 s (FEV1) after the inhalation of lysine–acetyl salicylic acid in AIA patients (P=0.009); AIA patients homozygous for the +795 C allele had a greater percent fall of FEV1 compared with individuals with TBXA2R+795 CT or TT genotypes. The frequency of patients carrying both the TBXA2R+795T〉C rare allele and HLA DPB1*0301 was significantly higher in AIA patients (29.4%) than in ATA patients (7.3%) (P=0.008, odds ratio=5.3).Conclusion These results suggest that the polymorphism of TBXA2R+795T〉C may increase bronchoconstrictive response to ASA, which could contribute to the development of the AIA phenotype.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2222.2005.02220.x
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  • 9
    Digitale Medien
    Digitale Medien
    ADAM33 polymorphism: association with bronchial hyper-responsiveness in Korean asthmatics (2004)
    Oxford, UK : Blackwell Science Ltd
    Clinical & experimental allergy 34 (2004), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background A disintegrin and metalloprotease 33 (ADAM33) is expressed in the lung by fibroblasts and bronchial smooth muscle cells. Given its structure and cellular provenance, ADAM33 may be associated with airway remodelling and bronchial hyper-responsiveness. Single nucleotide polymorphisms (SNPs) and haplotypes of the ADAM33 gene have previously been associated with asthma susceptibility in the Caucasian population.Objective and Methods To assess whether genetic variants of ADAM33 are related to asthma in a Korean population, we conducted an association study of the ADAM33 gene with asthma susceptibility, bronchial hyper-reactivity and serum IgE in Korean asthmatics (n=326) and normal controls (n=151). Five of the 14 polymorphisms originally reported to be associated with asthma development (S1 G〉A, T1 T〉C, V-1 C〉A, V1 T〉A, V4 C〉G) were genotyped using single base extension and electrophoresis. Haplotypes and their frequencies were inferred using the algorithm implemented by the software Arlequin. Allele frequencies of each SNP and haplotypes were compared between the patients and the normal controls using logistic regression analysis.Results There was no significant difference in the distribution of SNPs and the six haplotypes between asthmatics and normal controls. All single SNPs and six haplotypes in ADAM33 were also analysed for the association with level of PC20 using general linear models. The distribution of the T1 T〉C SNP and one haplotype (ht4: GCGG) showed significant association with log-transformed PC20 methacholine level in the asthma patients (P=0.03 and 0.0007, respectively, using a co-dominant model).Conclusion Polymorphism of ADAM33 may contribute to development of BHR in asthma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2222.2004.01977.x
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  • 10
    Digitale Medien
    Digitale Medien
    Association of interleukin 18 (IL18) polymorphisms with specific IgE levels to mite allergens among asthmatic patients (2005)
    Oxford, UK : Munksgaard International Publishers
    Allergy 60 (2005), S. 0 
    Details
    ISSN: 1398-9995
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background:  Allergy is regarded as a multifactorial condition. Its onset and severity are influenced by both genetic and environmental factors. Identification of genetic factors involved in asthma development and related phenotypes is a major task in understanding the genetic background of asthma. The possible involvement of IL18 polymorphisms in asthma was examined in a Korean asthma cohort.Methods:  Direct sequencing was performed to discover single-nucleotide polymorphisms (SNPs) in the IL18 gene. Single-base extension (SBE) method was employed for genotyping. Genotypic influence of IL18 was analysed using logistic and multiple-regression models.Results:  Although no polymorphisms in the IL18 gene showed significant association with the risk of asthma development, analyses of the association with specific serum IgE levels to Dermatophagoides farinae (D.f.) and D. pteronyssinus (D.p.) among asthmatic patients revealed significant associations with two completely linked SNPs, i.e. −148G〉C and +13925A〉C(Ser35Ser) (P = 0.01–0.11 for D.f. and P = 0.005–0.11 for D.p.). Both C allele of −148G〉C and C allele of +13925A〉C showed gene dose-dependent effects on the levels of specific IgE. The lowest IgE levels in homozygotes of minor alleles (1.13 and 1.22 of D.f.; 1.38 and 1.33 of D.p., respectively), intermediate IgE levels in heterozygotes (1.60 and 1.70 of D.f.; 1.84 and 1.92 of D.p., respectively), and the highest levels in homozygotes for major allele (1.93 and 1.93 of D.f.; 2.24 and 2.24 of D.p., respectively), were found.Conclusion:  The genetic relevance of IL18 to specific IgE might offer an important step in understanding the genetic background of allergic diseases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1398-9995.2005.00619.x
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