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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 724-728 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In order to study the formation of thermal vacancies in the Ti–Al alloy system, high-temperature positron lifetime measurements together with a modeling of defect formation in the framework of nearest-neighbor pair bonds were performed for α2Ti3Al and compared to recent results on γTiAl [U. Brossmann, R. Würschum, K. Badura, and H.-E. Schaefer, Phys. Rev. B 49, 6457 (1994)]. Substantial increases of the positron lifetime τ were observed for Ti65.6Al34.4 and Ti77.1Al22.9 in the temperature range T(approximately-greater-than)1200 K where thermal vacancy concentrations above the detection limit of positron annihilation are expected from the model calculations for the α2 phase. Within the high-temperature increase of the positron lifetime in the α2 and the β phase single-component positron lifetime spectra were observed. This behavior is in contrast to the two-component spectra observed conventionally at intermediate positron trapping rates and is attributed to a fast detrapping and retrapping of positrons at vacancies due to a low positron–vacancy binding energy. For this case, a vacancy formation enthalpy of HFV=(1.55±0.2) eV in α2Ti65.6Al34.4 and HFV=(1.8±0.2) eV in βTi77.1Al22.9 can be derived. These results are discussed in the context of recent 44Ti tracer diffusion studies. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 5143-5145 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In order to study the influence of the nanocrystalline microstructure on the magnetic properties of pure nanocrystalline metals, in situ magnetic measurements of high-purity nanocrystalline nickel, prepared by a gas-condensation technique with subsequent compaction at various pressures have been performed. The approach to ferromagnetic saturation indicates free volumes in the nanocrystalline system of the size of individual missing crystallites as well as internal stresses. While the saturation polarization of the nanocrystalline Ni samples appears to be unchanged compared to coarse-grained Ni the coercive field and magnetic domains are strongly influenced by the nanocrystalline structure. The shape of the domains with sizes of 10–200 μm much larger than the crystallite size depends on the annealing state of the specimen. The initial coercive field increases with the compaction pressure during preparation. Upon annealing it further increases to a maximum value at Ta=500 °C and decreases at higher annealing temperatures. Additionally, the effect of oxygen located in the grain boundaries has been studied. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Histopathology 37 (2000), S. 0 
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: AimsBone marrow histopathology reveals a striking heterogeneity at diagnosis of Philadelphia chromosome positive (Ph1+) chronic myelogenous leukaemia (CML). Based on semiquantitative evaluations of the number of megakaryocytes and the content of fibres, various histological subtypes have been postulated. However, little information exists on whether these groups represent stable categories of the different classification systems and whether therapeutic regimes exert any influence on the putative shift of histological patterns.Methods and resultsA retrospective clinicopathological study was performed on 396 bone marrow biopsies derived from 173 patients. There were at least two representative trephines taken at diagnosis and at median intervals of 16 months. Processing of the specimens involved immunostaining with CD61 (megakaryopoiesis) and Ret40f (erythropoiesis) and Gomori's silver impregnation technique. Based on morphometric analysis and in accordance with the general appearance of bone marrow histology three different histological subtypes were distinguished. These consisted of a granulocytic (51 patients), a predominantly megakaryocytic (73 patients) and a myelofibrotic pattern (49 patients). Follow-up biopsies revealed that a significant transition of histological groups occurred and that, independently of treatment modalities, the myelofibrotic category was associated with an unfavourable prognosis. Of the 124 patients without myelofibrosis at onset, 42% later transformed into the myelofibrotic subtype. However, these patients showed no prevalence of either a pre-existing granulocytic or megakaryocytic growth. Myelofibrotic changes were significantly associated with interferon (IFN) and busulfan (BU) therapy. On the other hand, a transition of a myelofibrotic into a nonfibrotic subtype was detectable in 17 of the 49 patients under study and related to hydroxyurea (HU) treatment.ConclusionsHistological classification systems of bone marrow features in CML do not represent stable patterns, but may be significantly altered by therapy, in particular IFN and HU.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Inst. and Methods in Physics Research, B 50 (1990), S. 300-306 
    ISSN: 0168-583X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Inst. and Methods in Physics Research, B 56-57 (1991), S. 621-624 
    ISSN: 0168-583X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Inst. and Methods in Physics Research, B 91 (1994), S. 263-268 
    ISSN: 0168-583X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0031-9163
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford UK : Blackwell Science Ltd
    Histopathology 39 (2001), S. 0 
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-2307
    Keywords: Adult Niemann-Pick disease ; Generalized AL-amyloidosis ; Progressive liver failure ; Fibroblast culture ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a case in which an adult form of Niemann-Pick disease (type B of NPD) was associated with a rapidly progressive generalized AL amyloidosis of kappa type. Both diagnosis were made by biopsy, the NPD by bone marrow biopsy and fibroblast culture, the amyloidosis by liver biopsy. Malignant non-Hodgkin lymphoma was not found. The patient, a 67-year-old woman, died from hepatic coma subsequent to a progressive liver failure. We discuss possible relations between the lysosomal storage disease and the development and rapid progression of amyloidosis.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of cancer research and clinical oncology 79 (1973), S. 11-18 
    ISSN: 1432-1335
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über zwei Fälle — eine 70 Jahre alt gewordene Frau und einen 66 Jahre alt gewordenen Mann — berichtet, bei denen post mortem ein interatrial gelegenes Lipom gefunden wurde, das von anderen Autoren auch als eine knotenförmige lipomatöse Hypertrophie im Vorhofseptum bezeichnet wird. In dem einen Fall bestand eine paroxysmale Tachyarhythmie mit Vorhofflimmern, die durch diese Fettgewebsgeschwulst erklärt werden könnte. Das Lipom bzw. die lipomatöse Hypertrophie im Vorhofseptum wurde mit einem Durchschnittsalter von 72 Jahren fast ausschließlich bei alten Menschen gefunden. Demgegenüber beträgt das Durchschnittsalter der Patienten bei den übrigen Fällen mit einem Lipom des Herzens 44 Jahre. Es sollte deshalb bei älteren Menschen mit einer Störung der Erregungsbildung im Vorhof differentialdiagnostisch auch an ein Lipom bzw. eine lipomatöse Hypertrophie im Vorhofseptum gedacht werden.
    Notes: Summary In a 70 years old woman suffering from paroxysmal tachyarhythmia and atrial fibrillation and in a 66 year old man, interatrial lipomas are discovered by post mortem examination. This lesion, named lipomatous hypertrophy of the interatrial septum by other authors, obviously is correlated with cardiac dysrhythmia. As seen from literature, interatrial lipomas are to be found in elderly patients with an average age of 72 years, whilst cardiac lipomas of other localizations are occurring in a medium age of 44 years. Therefore, interatrial lipomas should be taken in consideration in cases of cryptogenetic cardiac dysrhythmia.
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