GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1995-1999  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Analysis of the impact of dislocation distribution on the breakdown voltage of GaAs-based power varactor diodes (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 8294-8297 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A synchrotron x-ray topography analysis of the impact of the distribution of defects/dislocations on the electrical performance of GaAs power varactor diodes was carried out. Diodes fabricated on or near Liquid Encapsulated Czochralski cellular dislocation networks in the substrate, which are also known to be rich in As precipitates near these cell walls, were observed to have reduced breakdown voltages (VBR). This is consistent with the possibility that the presence of space-charge cylinders surrounding these dislocations gives rise to reduced VBR if they thread a p-n junction; it is also in accord with the possibility that the As precipitates themselves can act as sites for local field enhancement, thus promoting premature avalanche breakdown. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362470
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Differential dependence of TH-0, TH-1 and TH-2 CD4 4+ T cells on co-stimulatory activity provided by the accessory molecule LFA-1 (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 25 (1995), S. 0 
    Details
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background The adhesion molecule LFA-1 contributes to the activation response of peripheral blood human CD4+ T cells. Less is known of its contribution to stimulation of long-term CD4+ T cell lines and clones or of its potential to co-stimulate CD4+ T cells of different functional phenotype. Objective This study was therefore performed to investigate co-stimulatory properties of the LFA-1 (CD11a/CD 18) complex in the activation of human CD4+ T cell lines and clones of TH-0. TH-1 and TH-2 subsets. Methods Co-stimulatory activity was measured by cross-linking antibodies to CD 11a or CD18 with anti-CD3 antibodies to plastic and then measuring the proliferative response of CD4+ T cells to these antibodies. Results A house duct mite allergen-specific CD4+ T cell line (TH-2) demonstrated much greater dependence on both C'DI la and CD IK than a mycobacterial antigen-specific CD4+ T cell line (TH-1). Co-stimulatory activity through LFA-1 was also provided to a house dust mite-specific CD4+ T cell clone (DE-9; TH-2) but not to an influenza haemagglutinin-specific CD4+ T cell clone (HA 1.7: TH-0). In contrast, soluble antibodies to CD 18 inhibited proliferativc responses of both DE-9 and HA1.7 to an immunogenic challenge of antigen and to stimulation by unti-CD3 antibodies. However, the allergen-specific T cells were more susceptible to inhibition. Signal transduction was also observed from the T-cell receptor to LFA-1. Ligation of the T-cell receptor modulated the phenotypic expression of LFA-1 and ICAM-1 on both HA1-7 and DE-9). Phenotypic modulation was observed as a result of both activation and the induction of non-responsiveness. Conclusion These experiments indicate that CD4+ T cells of TH-2 functional phenotype may have a greater requirement for the co-stimulatory activity of LFA-1 than CD4+ T cells of TH-0 or TH-1 phenotypes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2222.1995.tb03039.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Clonal analysis of CD4 mediated accessory function on the effector activity of human CD4+ T cell subsets (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 25 (1995), S. 0 
    Details
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: It has been reported for the peripheral T cell repertoire that CD4 molecules may enhance adhesion between T cells and antigen presenting cells and, through their physical association with T cell antigen receptors, contribute to signal transduction.Objective: The aims of this study were to determine if the modulation of CD4 molecules had differential effects on T cell recognition, antigen induced cytokine (IL-4 and IFNγ), release and the induction of specific anergy for human TH-0, TH-1 and TH-2 cells.Methods: A panel of anti-CD4 antibodies was examined for its ability to modulate T cell proliferation, cytokine production and tolerance induction in house dust mite (TH-0 and TH-2) and influenza haemagglutinin (TH-1) specific human CD4+ T cell clones all restricted by DRB1*1101 and isolated from dust mite allergic individuals.Results: We observed that anti-CD4 antibodies may inhibit or enhance antigen mediated T cell proliferation, which may reflect the differential requirements of T cells for selective functions of CD4. Furthermore, IFNγ and IL-4 production was differentially modulated depending on the specificity of the anti-CD4 antibody and the clone of T cells. However, pretreatment of T cells with anti-CD4 antibody alone neither induced nor enhanced the susceptibility of T cells to peptide mediated anergy.Conclusion: Antigen recognition by different subsets of human CD4+ T cells has differential requirements on CD4, whereas the induction of specific anergy appeared to be independent of the functions of CD4 molecules. Antigen induced IFNγ production was more susceptible than IL-4 to the inhibitory effects of anti-CD4 antibodies. Furthermore, it appeared that certain anti-CD4 antibodies can dissociate antigen induced IFNγ and IL-4 production, and may downregulate IFNγ synthesis without inhibiting antigen dependent proliferation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2222.1995.tb00026.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A millimeter-wave monolithic grid amplifier (1995)
    Springer
    International journal of infrared and millimeter waves 16 (1995), S. 1901-1909 
    Details
    ISSN: 1572-9559
    Keywords: Grid Amplifier ; Quasioptical Amplifier ; Monolithic Technology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A 36-element monolithic grid amplifier has been fabricated. The peak gain is 5 dB at 40.8 GHz with a 3-dB bandwidth of 1.4 GHz. The active elements are pairs of heterojunction-bipolar-transistor's (HBT's). The individual transistors in the grid have a maximum oscillation frequency,f max , of 100 GHz. The grid includes base stabilizing capacitors which result in a highly stable grid. This is the first report of a successful monolithic grid amplifier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02072546
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...