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  • 2005-2009
  • 1995-1999  (17)
  • 1990-1994  (19)
  • 1996  (17)
  • 1994  (11)
  • 1991  (8)
  • 1
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The specific contact resistance ρc of non-alloyed ohmic metals (Mo/Au and WSix) to p-type GaAs is evaluated by transmission line method (TLM) patterns for various doping concentrations from 8×1018 to 1021 cm−3. The obtained specific contact resistance ρc, less than 10−8 Ω cm2, to metalorganic molecular beam epitaxy grown C-doped ( 1021 cm−3) GaAs is the lowest reported value. From the application point of view for the emitter electrodes of PNp type (two-dimensional electron gas base) heterojunction bipolar transistors, the specific contact resistance of a refractory metal, or the sputter-deposited WSix (x=0.45), is also studied. By reducing the growth temperature of molecular beam epitaxy from 600 to 450 °C and enhancing the As4/Ga flux ratio to 15, a nondiffusive heavily Be doped (1020 cm−3) GaAs is obtained. The specific contact resistance of the WSix to this sample is less than 10−6 Ω cm2. The obtained specific contact resistance can be well explained by a simple modeling based on the tunneling transport of light holes. Secondary ion mass spectroscopy analysis of the depth profile under heat acceleration shows a small diffusion of dopants for Be doped (1020 cm−3) GaAs and C-doped (1021 cm−3) GaAs. In addition, the specific contact resistance ρcISO of the isoheterojunction (p+GaAs/p+AlxGa1−xAs) is also evaluated by TLM patterns.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 2788-2790 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Despite the valence difference across the junction, it has been shown that ZnSe/GaAs epilayer/epilayer interface state densities can be reduced to values comparable to the (Al,Ga)As/GaAs interface. We have previously reported a transmission electron microscopy study indicating that ZnSe/GaAs structures exhibiting low interface state densities are associated with the formation of an interfacial layer of zinc-blende Ga2Se3. In this letter we describe a procedure whereby an interfacial layer can be deliberately introduced prior to nucleation of ZnSe. In situ x-ray photoelectron spectroscopy is used to study the nature of the bonding at the interfacial layer. A comparison of the Se 3d core level features from the ZnSe epilayer surface, a Se-reacted GaAs surface, and from a separately grown Ga2Se3 epilayer, clearly indicates the same Se bonding characteristic for the Se-reacted interfacial layer and the Ga2Se3 epilayer.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 3619-3621 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Laser diode action in the blue-green has been observed from (Zn,Cd)Se quantum wells within ZnSe/Zn(S,Se) p-n heterojunctions up to 250 K. Operation is reported for two different configurations for which the GaAs substrate serves either as the n- or p-type injecting contact. In pulsed operation, output powers exceeding 0.6 W have been measured in devices prepared on both n-type and p-type GaAs epitaxial buffer layers and substrates.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report in vivo laser computed tomographic images of the proximal interphalangeal joint region of a healthy human volunteer's index finger. The laser computed tomographic (CT) images were obtained with a highly sensitive coherent detection imaging method that is based on the optical heterodyne detection method. These laser CT images are compared at the wavelengths of 715 nm and 1.064 μm and with images obtained by conventional imaging methods such as x-ray CT and magnetic resonance imaging. Internal structures of the proximal interphalangeal joint region could be clearly identified in the laser CT images. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Previous observations suggest that interleukin-1 (IL-1) may play an important role in the progression of periodontitis. In the present study, we investigated whether a cell-associated IL-1α (CAIL-lα) produced in human gingival fibroblasts (HGF) induces biological activities related to the progression of periodontitis. HGF were treated with recombinant human IL-1β (rhIL-1β) for 12 h. After that, the cell layers of HGF were washed 3 times with fresh medium and were then fixed with 1% paraformaldehyde. The fixed cell layers of HGF were used for assays for bone resorbing activity, prostaglandin E2 (PGE2) production and collagenase activity. Fixed cell layers of HGF treated with rhIL-1β enhanced not only calcium release from BALB/c mouse calvaria but also PGE2 production and collagenase activity in HGF and human periodontal ligament fibroblasts (HPLF) cultured on the fixed cell layers. These activities were neutralized by treatment with monoclonal mouse anti-human IL-1α antibody, but monoclonal mouse antihuman IL-1β antibody showed no effects on these activities. The induction of these activities by fixed cell layers of HGF required direct contact between the fixed cell layers and the calvaria, HGF, or HPLF. These results suggest that CAIL-1α produced in HGF treated with rhIL-1β induces bone resorbing activity, PGE2 production and collagenase activity in the target cells by direct contact; CAIL-lα may play an important role in the progression of periodontitis.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of applied ichthyology 7 (1991), S. 0 
    ISSN: 1439-0426
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Rainbow trout, Oncorhynchus mykiss, injected with a water fraction extracted from abalone, Haliotis discus hannai, showed enhanced phagocytosis. This enhanced activity reached its maximum level 5 days after injection. The natural killer cell activities and the chemiluminescence responses of kidney leukocytes in fish treated with this fraction were also significantly increased, compared to those in albumin-treated fish. Rainbow trout injected intraperitoneally with this fraction showed an increased resistance to Vibrio anguillarum.〈section xml:id="abs1-2"〉〈title type="main"〉Zusammenfassung Immunomodulationseffekte bei Regenbogenforellen, Oncorhynchus mykiss, nach Injektion von Aba-lone-Entrakt, Haliotis discus hannaiBei Regenbogenforellen, Oncorynchus mykiss, denen ein wäßriger Extrakt der Abalone, Haliotis discus hannai, injiziert wurde, konnte eine gesteigerte Phagocytoseaktivität beobachtet werden. Diese Aktivi-tätssteigerung erreichte 5 Tage nach Verabreichung der Injektion ihr Maximum. Die natürliche Aktivi-tat von Killer-Zellen und die Chemoluminizenz-Reaktion der Nieren-Leukozyten in den mit dem Extrakt behandelten Fischen waren gegenüber Tieren, denen Albumin injiziert wurde, signifikant erhoht. Regenbogenforellen, denen der Abalone-Extrakt intraperitoneal injiziert wurde, zeigten eine erhohte Resistenz gegen Vibrio anguillarum.〈section xml:id="abs1-3"〉〈title type="main"〉Résumé Effects immunomodulatoires chez la truite arc-en-ciel, Onchorhynchus mykiss, traitie par des injections d'extraits d'onneaux, Haliotis discus hannai La truite arc-en-ciel, Onchorhynchus mykiss, traitie par injection d'une fraction aqueuse extraite d'ormeaux, Haliotis discus hannai, a montré une augmentation du taux de phagocytose. Cette augmentation de I'activité a atteint son niveau maximal cinq jours aprés injection. Les activitts naturelles des cellules tueuses et les résonses chimioluminescentes des leucocytes du rein des poissons traitis par cette fraction ont aussi significativement augmentis, par rapport ä celle des poissons traitis par de l'albumine. Les truites arc-en-ciel uaities par des injections intrapiritoniales de cette fraction ont montré une résistance accrue äVibrio anguillarum.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 50 (1994), S. 245-247 
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 50 (1994), S. 247-250 
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The antiviral extract from Rhodopseudomonas capsulata was purified and the predominant active component was defined as cis-vaccenic acid (C1- 8:1 Δ11) by gas-liquid chromatography and gas chromatography-mass spectrometry analyses. Antiviral activities of unsaturated fatty acids and related alcohols against T5 phage were also tested. Among them, linoelaidic acid, oleic acid, and petroselenyl alcohol inactivated 98%, 53%, 67% of T5 phage at the concentration of 50 μ g/ml, respectively.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1420-9071
    Keywords: Organogermanium compound ; contrasuppressor T cells ; suppressor T cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract 2-Carboxyethylgermanium sesquioxide (Ge-132), a synthesized organogermanium compound with immunomodulaing activities, was shown to be an inducer of anti-suppressor T cells in normal mice. The suppressor cell activity of T6S cells, a clone of burn-induced CD8+ IL-4-producing suppressor T cells, was clearly inhibited when a mixed lymphocyte-tumor cell reaction of the clone was conducted with splenic mononuclear cells from mice treated orally with a 100 mg/kg dose of Ge-132. The activity of anti-suppressor cells was demonstrated in spleens of mice 2 days after treatment with Ge-132 and reached its peak on day 3. The anti-suppressor cells induced by the compound were of a contrasuppressor T cell-linage, because they were characterized as CD4+ CD28+ TCRα/β+ Vicia villosa lectin-adherent T cells. These cells produced IFN-γ but did not produce IL-2, IL-4, IL-6 or IL-10 in their culture fluids. CD4+ anti-suppressor T cells induced by Ge-132 may be different from other subsets of CD4+ T cells because Th1 and Th2 cells generated in our laboratory did not adhere toVicia villosa lectin-coated petri dishes, and each produced specific cytokines. Th1 cells produced IFN-γ and IL-2 while Th2 cells produce IL-4 and IL-10 in vitro. These results suggest that Ge-132 may be useful as an inducer of contrasuppressor T cells in immunocompromised individuals bearing suppressor T cells. To eliminate suppressor T cells from immunocompromised hosts may result in improved resistance from various opportunistic infections.
    Type of Medium: Electronic Resource
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