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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 6262-6267 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A mechanism explaining the breakdown of dielectrics with high intrinsic inhomogeneity like natural rocks and concrete is proposed and proved experimentally. This work has a very promising industrial application in the drilling and demolition of natural and artificial solid materials by electric pulses. The mechanism includes the breakdown of gas cavities inside the dielectric and on its surface. At a very high applied voltage, the high electric field causes the breakdown in the cavities. The displacement and conduction currents flowing through a number of such cavities result in the heating of the plasma and high pressure pulse generation. The pulsed pressure results in crack formation and finally, in the destruction of a solid material. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] The origin of the cosmic X-ray background radiation, has remained mysterious since its discovery thirty-five years ago. Investigation of its origin has been difficult because instruments have had insufficient resolution to distinguish small, faint sources in the hard X-ray band (above ...
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-0428
    Schlagwort(e): Keywords Type II (non-insulin-dependent) diabetes mellitus ; gene ; inwardly rectifier potassium channel ; mutation.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The K+ inwardly rectifier channel (KIR) is one of the two sub-units of the pancreatic islet ATP-sensitive potassium channel complex (IKATP), which has a key role in glucose-stimulated insulin secretion and thus is a potential candidate for a genetic defect in Type II (non-insulin-dependent) diabetes mellitus. We did a molecular screening of the KIR6.2 gene by single strand conformational polymorphism (SSCP) and direct sequencing in 72 French Caucasian Type II diabetic families. We identified three nucleotide substitutions resulting in three amino acid changes (E23K, L270V and I337V), that have also been identified in other Caucasian Type II diabetic subjects. These variants were genotyped in French cohorts of 191 unrelated Type II diabetic probands and 119 normoglycaemic control subjects and association studies were done. The genotype frequencies of the L270V and I337V variants were not very different between Type II diabetic subjects and control groups. In contrast, analysis of the E23K variant showed that the KK homozygocity was more frequent in Type II diabetic than in control subjects (27 vs 14 %, p = 0.015). Analyses in a recessive model (KK vs EK/EE) tended to show a stronger association of the K allele with diabetes (p = 0.0097, corrected p-value for multiple testing 〈 0.02). The data for the E23K variant obtained here and those obtained from three other Caucasian groups studied so far were combined and investigated by meta-analysis. Overall, the E23K variant was found to be significantly associated with Type II diabetes (0.001 ≤p≤ 0.0016, corrected p-values for multiple testing p≤ 0.01). This study shows that KIR6.2 polymorphisms are frequently associated with Type II diabetes in French Caucasians. Furthermore, a meta-analysis combining different Caucasian groups suggests an significant role of KIR6.2 in the polygenic context of Type II diabetes. [Diabetologia (1998) 41: 1511–1515]
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-0983
    Schlagwort(e): Key wordsNeurospora crassa ; Nucleotide excision repair ; mus-38 ; RAD1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A Neurospora crassa gene encoding a product with homology to the Saccharomyces cerevisiae Rad1 nucleotide excision repair (NER) protein was isolated by degenerate PCR. The predicted protein consists of 892 amino acids with a molecular weight of 100.4 kDa, and 32–37% identity to the XPF/ERCC4 protein family. The homolog was mapped to the left arm of linkage group I, the location of the mus-38 gene. Subsequently, gene inactivation and complementation studies identified the RAD1 homolog as mus-38. Immunological assays showed that the mus-18 (UV-specific endonuclease) and mus-38 strains have partial and normal UV-damage excision activities, respectively, but removal of thymine dimers and TC (6-4) photoproducts is abolished in the mus-18 mus-38 double mutant. The double mutant also was synergistically more sensitive to UV than either single mutant. The data suggest that mus-38 may participate in a different NER pathway from that involving the mus-18 gene.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-0630
    Schlagwort(e): PACS: 61.16.-d; 68.35.Bs; 73.20.At
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: 9  atoms/cm2. In this study, in order to achieve an elementary analysis of each atom on the Si surface, metal atoms on the Si(001) surface are analyzed by STS and the result is evaluated with the first principles calculations of quantum mechanics. As metallic contaminations, sub-monolayer of Aluminum is evaporated on Si(001)2×1. The Local Density of State (LDOS) on the Al/Si(001)2×1 is measured by STS at room temperature. The measured LDOS at an Al dimer is in good agreement with that obtained from the calculation.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Abdominal imaging 23 (1998), S. 191-193 
    ISSN: 1432-0509
    Schlagwort(e): Key words: Intrapancreatic accessory spleen—CT—MRI.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. We report a rare case of intrapancreatic accessory spleen which radiologically mimicked a pancreatic hypervascular tumor. The diagnosis of an intrapancreatic accessory spleen should be considered when a pancreatic mass has the CT densities and/or MR signal intensities similar to those of the spleen, with and without contrast medium.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Journal of sol gel science and technology 11 (1998), S. 117-124 
    ISSN: 1573-4846
    Schlagwort(e): gold metal particles ; coating films ; gas diffusion method ; surface plasma resonance ; hydroxypropyl cellulose
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Au particles dispersed thin metal oxide films were prepared from precursor films containing HAuCl4 with H2S gas diffusion method. HAuCl4 was uniformly dissolved in the films as promoted by hydroxypropyl cellulose (HPC). The mechanism of the Au particle formation was studied. It was found that HAuCl4 was converted directly to Au metal particles upon contacting with H2S gas. Au particles generated by this method were characterized with small particle size, sharp size distribution and high volume fraction in the films. The surface plasma resonance absorption of Au particles shifted to longer wavelength when TiO2 component was introduced in the matrix.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Journal of materials science 33 (1998), S. 749-754 
    ISSN: 1573-4803
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract CaO–Al2O3–SiO2 –La2O3–Nd2O3 glass was prepared and their physical properties, such as density, glass transition temperature and crystallization temperature, were measured. The heat treatment of these glasses precipitated Ca2La8(SiO4)6O2 oxyapatite (CLS) crystal for 20CaO–10Al2O3–60SiO2–10La2O3 (mol%) glass and Ca2Nd8(SiO4)6O2 oxyapatite (CNS) crystal was precipitated with Nd2O3 substitution. Crystallization of these glasses was observed at the surface and internally within the samples. The spherical and stick-like crystals were observed throughout the bulk of the glasses and the surface crystal layer of oxyapatite crystals were strongly oriented along the c-axis. The apparent activation energies of crystal growth were estimated as 360 kJ mol−1.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Archives of orthopaedic and trauma surgery 118 (1998), S. 136-139 
    ISSN: 1434-3916
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We performed five reconstructions by bone transport in patients with bone sarcoma: three osteosarcomas, one Ewing’s sarcoma and one chondrosarcoma. Four sacromas were in the distal femur and one in the shaft of the tibia. Four patients received multidrug chemotherapy. The average length of the skeletal defect after tumour resection was 17 (range 10–25) cm. All patients underwent double elongation from both proximal and distal sites of the bone defect. The average follow-up period was 48 (range 40–66) months, and the average duration of external fixation was 32 months (range 579–1340 days). In one case, bone formation was satisfactory, but in the other cases, it was poor and slow. The average treatment index was 95 (range 53–191) days per 1 cm of elongation. In one case, the bone fragment disappeared during the bone transport. In one case, the end of the bone protruded from the skin, and osteomyelitis set in. This patient underwent above-knee amputation due to failure of infection control. Three patients suffered talipes equinus. One patient died of pulmonary metastasis. Two patients had fair and three had poor function. This method is not recommended for patients with bone sarcoma who may have a poor prognosis, as it has an unacceptably high complication rate.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1617-4623
    Schlagwort(e): Key wordslah-1 ; cpc-1 ; Laccase ; Cycloheximide-inducible genes ; Neurospora crassa
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In Neurospora crassa, expression of the laccase gene is induced by treatment with the protein synthesis inhibitor cycloheximide (CHX). This expression is mediated by CPC1, which acts as a general transcriptional activator when mycelia are treated with CHX or starved for any one of the amino acids. A laccase-derepressed mutant, lah-1, shows pleiotropic deficiencies in growth, hyphal morphology, CHX sensitivity, and production of protoperithecia. Moreover, in the lah-1 mutant, transcript levels of CHX-inducible genes, including lacc, tub-2, tef-1, and amino acid biosynthetic genes such as cpc-1, trp-3, and arg-12, are increased without exposure to CHX. All of the defects exhibited in the lah-1 mutant are suppressed by a mutation in the cpc-1 locus. These findings suggest that the cpc-1 mutation is epistatic to the lah-1 mutation and that the pleiotropic defects in the lah-1 mutant are attributable to constitutive expression of CPC1. These conclusions are supported by a developmental Northern blot analysis of the CHX-inducible genes. Based on these results, the lah-1 gene product appears to regulate expression of the cpc-1 gene negatively. Expression of the CHX-inducible genes was induced by CHX treatment in the lah-1 cpc-1 mutant, as well as in the cpc-1 mutant. This observation indicates that LAH1 is not a component of CHX-responsive pathway itself.
    Materialart: Digitale Medien
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