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  • 1
    ISSN: 1420-9071
    Keywords: Bradyrhizobium ; communication ; competitiveness ; Rhizobium ; vesicular-arbuscular (VA) mycorrhiza fungi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract After a short summary on the ecology and rhizosphere biology of symbiotic bacteria and vesicular-arbuscular (VA) mycorrhiza fungi and their application as microbial inocula, results on competitiveness and communication are summarized. Stress factors such as high temperature, low soil pH, aluminium concentrations and phytoalexins produced by the host plants were studied withRhizobium leguminosarum bv.phaseoli andRhizobium tropici onPhaseolus beans. Quantitative data for competitiveness were obtained by usinggus + (glucoronidase) labelled strains, which produce blue-coloured nodules. ForPhaseolus-nodulating rhizobia, a group specific DNA probe was also developed, which did not hybridize with more than 20 other common soil and rhizosphere bacteria. Results from several laboratories contributing to knowledge of signal exchange and communication in theRhizobium/Bradyrhizobium legume system are summarized in a new scheme, including also defense reactions at the early stages of legume nodule initiation. Stimulating effects of flavonoids on germination and growth of VA mycorrhiza fungi were also found. A constitutive antifungal compound in pea roots, β-isoxazolinonyl-alanine, was characterized.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0789
    Keywords: Earthworm burrows ; X-ray computed tomography ; three-dimensional visualization ; Allolobophora caliginosa ; Octolasium cyaneum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Earthworm burrows of endogeic species (Allolobophora caliginosa, Octolasium cyaneum) in artificially packed soil columns were examined using X-ray computed tomography. By means of digital image processing, it was possible to reconstruct and visualize the burrow system in three dimensions. The reconstruction revealed morphological features of the burrows which were not obvious from two-dimensional section images.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0630
    Keywords: 68.55 ; 68.65 ; 78.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Mo/Si multilayers are fabricated by electron-beam evaporation in UHV at different temperatures (30° C, 150° C, 200° C) during deposition. After completion their thermal stability is tested by baking them at temperatures (T bak) between 200° C and 800° C in steps of 50° C or 100° C. After each baking step the multilayers are characterized by small angle CuKα-X-ray diffraction. Additionally, the normal incidence soft-X-ray reflectivity for wavelengths between 11 nm and 19 nm is determined after baking at 500° C. Furthermore, the layer structure of the multilayers is investigated by means of Rutherford Backscattering Spectroscopy (RBS) and sputter/Auger Electron Spectroscopy (AES) technique. While the reflectivity turns out to be highest for a deposition temperature of 150° C, the thermal stability of the multilayer increases with deposition temperature. The multilayer deposited at 200° C stands even a 20 min 500° C baking without considerable changes in the reflectivity behaviour.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1076
    Keywords: Osteogenesis imperfecta ; Joint contractures ; Collagen fibrils ; Mineralization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We describe a male patient with osteogenesis imperfecta (OI) who was born with contractures of the knee, elbow and ankle joints. During the first 4 years he suffered from recurrent fractures. He has white sclerae, mild dentinogenesis imperfecta, multiple wormian bones, severe scoliosis and short stature. Morphological analysis of cortical bone revealed typical characteristics of OI including varying width of the osteoid, swollen mitochondria and a dilated endoplasmic reticulum of the osteoblasts. Collagen fibrils of the osteoid had a varying diameter, a feature not found in typical OI patients. Analysis of compact bone showed that the size of apatite crystals and the extractability of collagen with pepsin were markedly elevated compared to controls and other OI type III and IV patients. Lysyl hydroxylation of collagen from the organic bone matrix and the electrophoretic mobility of collagen α1(I)- and α2(I)-chains were normal. Our results provide evidence that this patient belongs to a subtype of OI. The biochemical studies indicate that the underlying defect involves defective fibril-formation of collagen type I leading to an altered mineralization of bone.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1041
    Keywords: Repaglinide ; Glibenclamide ; Diabetes mellitus ; oral hypoglycaemic agent ; Phase II study ; metabolic control ; non-insulin-dependent diabetes ; adverse effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary We have evaluated the effects of repaglinide, a new non-sulphonylurea oral hypoglycaemic agent that has a stimulatory effect on insulin secretion. Forty-four patients with NIDDM, already treated with a sulphonylurea, took part in an open, randomised, group comparison study of 12 weeks duration, during which they received either repaglinide or glibenclamide twice daily. While glibenclamide had a greater effect on fasting blood glucose (10.4 to 8.6 mmol·l−1), repaglinide significantly lowered postprandial blood glucose (13.8 to 12.2 mmol· l−1). Glycosylated haemoglobin remained unchanged in both groups, and serum fructosamine showed a tendency to fall. With both treatments total cholesterol was significantly decreased after 12 weeks, while HDL-cholesterol and triglycerides did not change. Fasting plasma insulin in the repaglinide group decreased from 80 (median value) to 67 pmol·l−1; it did not change in the glibenclamide group. Two patients in the repaglinide group did not complete the study, one for personal reasons, and one because of a rise in blood glucose. No abnormal findings attributable to repaglinide were observed in clinical and laboratory examinations, and no hypoglycaemic symptoms caused by it were observed.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 580 (1990), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of structural, chemical, and extreme ultraviolet (EUV) characterization of Si/Mo multilayers grown by sputtering and by UHV evaporation. This study includes mirrors designed for normal incidence with peak reflectivities Rpeak between 22 and 24 nm, and 45° mirrors having Rpeak between 16 and 19 nm. The deposition conditions were varied to produce multilayers with a wide range of interface morphologies. A variety of techniques were used to determine the structure and composition of the multilayers, including x-ray diffraction, transmission electron microscopy, Rutherford backscattering spectroscopy, and Auger depth profiling. All of the mirrors have amorphous Si layers and polycrystalline Mo layers with thin amorphous alloy interlayers. We obtain good fits to the low-angle x-ray diffraction data only when these interlayers are taken into account. The best sputter-deposited mirrors were made at the lowest Ar pressure studied, 3 mTorr. The best evaporated mirrors were produced at a substrate temperature of 200 °C. The EUV reflectivity as a function of wavelength was measured using synchrotron radiation. Both the multilayer structure and surface contamination significantly affect the EUV reflectivity, and must be considered to obtain good fits to the reflectivity curves. The best 45° mirror had a peak reflectivity of 53% at 18.6 nm for 100% S-polarized light, and the best normal-incidence mirror had a peak reflectivity of 33% at 23.6 nm.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 3814-3821 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Semi-insulating Fe-doped 〈100〉-InP wafers were implanted in a nonchanneling direction with 300 keV Si+ and 600 keV Se++ ions in the dose range of 1×1012–1×1016 cm−2. The implantation temperature was varied between room temperature and 425 K. The samples were capped and short time annealed by means of a graphite strip heater at 700–975 °C. The defect investigation of the as-implanted as well as of the annealed samples was performed with Rutherford backscattering spectrometry. A simple vacancy diffusion model is applied to describe the damage production, which yields critical implantation temperatures for amorphization. These temperatures are approximately 390 K for Si and 420 K for Se, for higher temperatures amorphization is not possible in InP. The electrical properties of the annealed layers are measured by the van der Pauw–Hall technique. The results are discussed with respect to the residual damage after annealing. Saturation values of the electrical activation were achieved at 3×1014 cm−2 for Si and 4×1014 cm−2 for Se, respectively.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 65 (1994), S. 3229-3232 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new beamline for radiometric applications (e.g., detector calibration and reflectometry) has been installed and characterized at the laboratory of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY. The beamline is equipped with a SX700 type plane grating monochromator and a toroidal mirror behind the exit slit of the monochromator for collimating the radiation to allow angle resolved reflectometry. A divergence of 0.1 mrad has been achieved. The beamline has been optimized for high spectral purity of the radiation. Within the photon energy range from 40 to about 1500 eV the total amount of stray light and higher order radiation stays below 1%. A photon flux of up to 1011 s−1 has been measured in the focal point of the toroidal mirror. It corresponds to a radiant power of a few μW and thus allows use of a cryogenic radiometer for detector calibration. The details of the beamline layout and the results of the performance characterization are presented.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 2207-2209 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Multilayer soft x-ray mirrors with an absorber consisting of the mixture Mo0.5Si0.5 have been fabricated by electron-beam evaporation in UHV. This has been done to get soft x-ray normal incidence mirrors for 80–100 eV photon energy with enhanced thermal stability and still high reflectivity. The thermal stability is studied by baking them at temperatures between 600 and 950 °C. The results were compared with multilayers of pure Mo and Si, which were also fabricated by electron-beam evaporation. After each baking step the x-ray mirrors are characterized by small angle CuKα x-ray diffraction. The reflectivity of the first-order Bragg peak is nearly constant up to 20 min baking at 900 °C. Further we present the normal incidence soft x-ray reflectivity for wavelengths between 12 and 18 nm of a Mo0.5Si0.5/Si mirror with 12 double layers (N=12) and of a Mo0.5Si0.5/Si mirror as deposited with 33 double layers (N=33). With the latter a reflectivity of 46% is achieved.
    Type of Medium: Electronic Resource
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