Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 118-121 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Proton implantation into neutron transmutation doped (NTD) silicon generates three hydrogen-related effective mass-like donors with binding energies between 35 and 44 meV. The donors are formed by the complexing of hydrogen with damage induced by the irradiation. Our results indicate residual defects even in well annealed NTD silicon. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 424-426 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Hydrogen neutralizes both donors and acceptors in GaP by a mechanism that is independent of the site of the impurity in the lattice, but is dependent on the identity of the impurity. Hydrogen also passivates an isoelectronic trap nitrogen, a phenomenon first encountered here in GaP. We propose a simple model for the NH binding based on a polarized N−H+ bond. This model accounts for the relative passivation of a series of NN pairs, where the passivation depends critically on the NN separation distance. Our results also support the recently revised correlation of spectral lines with NN pairs of varying separations.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 2686-2688 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on electroluminescence at room temperature from forward biased n+–p silicon diodes containing high densities (108–109 cm−2) of dislocations at the junction interface. In addition to electroluminescence from band-to-band transitions, we observe a signal with a comparable intensity peaked at ∼1.6 μm (0.78 eV). From luminescence studies below room temperature we deduce that the 1.6 μm emission originates from the well known dislocation-related center D1. The D1 electroluminescence intensity at room temperature increases linearly with current density with no observable saturation. The external efficiency of the D1 electroluminescence at room temperature was estimated to be of the order 10−6. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We recently reported that lasting activation of mouse microglial cells with bacterial lipopolysaccharide (LPS) chronically elevated the basal intracellular calcium concentration ([Ca2+]i). This correlated to an attenuated calcium signaling of complement (C5a) and purinergic (UTP) receptors as well as to the capacity for effective production of cytokines–chemokines. Here, we demonstrate that these adjustments in the [Ca2+]i regulation require a critical protein tyrosine kinase (PTK) function – even in varying stimulation scenarios. Changes in basal [Ca2+]i and calcium signaling are not restricted to Gram-negative bacterial confrontation. Pneumococcal cell wall (PCW) modelling Gram-positive infection causes virtually the same effects. Moreover, decreases in calcium signaling efficacy are neither associated with altered receptor expression, nor mediated by autocrine loops. Administration of microglial release products, transfer of conditioned supernatant or presence of a radical scavenger during LPS or PCW treatments have no consequence. However, both the elevation in basal [Ca2+]i as well as the suppression of C5a- and UTP-evoked calcium signals are selectively and dose-dependently reversed by tyrphostin AG126, a PTK inhibitor that, moreover, blocks inducible nitric oxide and cytokine–chemokine release. The findings suggest that the AG126-sensitive PTK critically controls both sensory and executive features of the microglial activation process via sustained up-regulation of basal [Ca2+]i.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: During bacterial infections of the CNS, activated microglia could support leucocyte recruitment to the brain through the synthesis of cyto- and chemokines. In turn, invading leucocytes may feedback on microglial cells to influence their chemokine release pattern. Here, we analyzed the capacity of interferon-γ (IFNγ) to serve as such a leucocyte-to-microglia signal. Production of cyto- and chemokines was stimulated in mouse microglia cultures by treatments with lipopolysaccharide (LPS) from Gram-negative Escherichia coli or cell walls from Gram-positive Streptococcus pneumoniae (PCW). IFNγ presence during the stimulation (0.1–100 ng/mL) modulated the patterns of LPS- and PCW-induced cyto- and chemokine release in a dose-dependent, potent and complex manner. While amounts of TNFα and IL-6 remained nearly unchanged, IFNγ enhanced the production of IL-12, MCP-1 and RANTES, but attenuated that of KC, MIP-1α and MIP-2. Release modulation was obtained with IFNγ preincubation (treatment of cells before LPS or PCW administration), coincubation and even delayed addition to an ongoing LPS or PCW stimulation. Together the changes observed for the microglial chemokine release under IFNγ would shift the chemoattractive profile from favouring neutrophils to a preferential attraction of monocytes and T lymphocyte populations – as actually seen during the course of bacterial meningitis. The findings support the view of activated microglia as a major intrinsic source for an instant production of a variety of chemokines and suggest that leucocyte-derived IFNγ could potentially regulate the microglial chemokine release pattern.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1433-0423
    Keywords: Schlüsselwörter Standardperimetrie ; Blau-Gelb-Perimetrie ; Amotio retinae ; Postoperativer Empfindlichkeitsanstieg ; Key words White-on-white-perimetry ; Blue-on-yellow-perimetry ; Retinal detachment ; Retinal sensitivity recovery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Introduction: Disturbance of the blue light perceptance in rhegmatogenous retinal detachment was demonstrated by Köllner 1907 with the help of colour-perimetries. We examined the blue- and white-function after retinal reattachment by blue-on-yellow-perimetry compared with white-on-white-perimetry. Patients and methods: 10 Patients with rhegmatogenous retinal detachment and a visual acuity ≥0.1 were examined preoperatively, 4 days and 6 weeks after successfull buckling procedure. We performed a white-on-white-perimetry as also perimetries with blue stimuli on a yellow luminance background (program 30–2 of the Humphrey Field Analyzer 750). Results: Four days after surgery the increase in sensitivity was significantly less for the blue-function compared with the white-function. Preoperatively and 6 weeks postoperatively the sensitivities were not significantly different. Between these time-points function recovered in average for both methods from MD –15 dB to MD –5 dB. Conclusion: After successful retinal detachment surgery the blue- and white-function increased. Blue-on-yellow-perimetry showed more retinal sensitivity loss than white-on-white-perimetry immediately after surgery. Blue-on-yellow-perimetry measured the same retinal sensitivity loss as white-on-white-perimetry preoperatively and 6 weeks postoperatively.
    Notes: Zusammenfassung Hintergrund: Eine Störung der Blauwahrnehmung bei Amotio retinae zeigte Köllner bereits 1907 anhand von kinetischen Farbperimetrien. Wir untersuchten die Blau- und die Wießfunktion nach Wiederanlage der Netzhaut anhand einer Blau-Gelb-Perimetrie im Vergleich zur Weiß-Weiß-Perimetrie. Patienten und Methoden: Untersucht wurden 10 Patienten mit rhegmatogener Amotio retinae und einem Visus ≥0.1 präoperativ, sowie 4 Tage und 6 Wochen nach erfolgreicher eindellender Operation. Es erfolgten Standardperimetrien und Perimetrien mit blauen Stimuli auf gelbem Hintergrund (Programm 30–2, Humphrey Field Analyzer 750) Ergebnisse: Unmittelbar postoperativ zeigte sich ein Empfindlichkeitsanstieg, der für die Blaufunktion signifikant geringer war als für die Weißfunktion. Präoperativ und 6 Wochen postoperativ unterschieden sich die Empfindlichkeiten nicht signifikant. Zwischen diesen Terminen erholte sich die Funktion im Mittel bei beiden Methoden von rund –15 dB auf rund –5 dB des MD-Wertes. Schlussfolgerung: Nach erfolgreicher Amotiooperation war für beide Methoden ein Empfindlichkeitsanstieg messbar. Unmittelbar postoperativ war der Empfindlichkeitsanstieg für die Weiß-Weiß-Perimetrie jedoch größer als für die Blau-Gelb-Perimetrie. Präoperativ und 6 Wochen postoperativ war die Schadenstiefe bei beiden Methoden gleich.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 117-118 (Jan. 1993), p. 309-314 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 143-147 (Oct. 1993), p. 873-878 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 143-147 (Oct. 1993), p. 1571-1576 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 258-263 (Dec. 1997), p. 1009-1014 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...