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  • 1995-1999  (1)
  • 1985-1989  (3)
  • 42.60B  (2)
  • Life and Medical Sciences  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 37 (1985), S. 171-179 
    ISSN: 1432-0649
    Keywords: 42.55D ; 42.60B ; 58.80
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The performance of a compact uv photo-preionized TE laser is studied in the pressure range 1–5 bar. As the pressure is increased, the laser pulse shape is little altered, but both the peak power and the total output pulse energy increase significantly with pressure, even for constant input electrical energy. For various gas mixtures and excitation source capacitors the measurements suggest approximate output energy scaling with the product of the source charge per unit electrode area [C.m−2] and the molecular partial pressure [CO2+N2+CO]. This is explained in terms of the pressure-dependent discharge impedance. An input-energy-related discharge instability limits the optimum laser pressure to 1.5–2.5 bar, and we show that, at constant input energy, the instability boundary depends on the molecular partial pressure alone. The pre-ionization photo-electron yield varies negligibly with pressure, but the discharge tolerance to added oxygen decreases asp −3 top −4, dependent on gas mixture. Nevertheless sealed operation for 〉105 shots has been obtained with a 5% CO2∶5% CO∶3% N2∶2% H2∶85% He gas mixture at a total pressure of 5 bar.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 37 (1985), S. 219-221 
    ISSN: 1432-0649
    Keywords: 42.55D ; 33.80E ; 52.80 ; 42.60B
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A short pulse (100 ns) high-energy x-ray source has been used to preionize a transversely excited carbon dioxide gas discharge laser of 600 cm3 active volume. The maximum output power of 60 MW in a 50 ns FWHM pulse was achieved from a CO2−N2−He−CO−Xe static gas mixture at 600 Torr pressure. The energy conversion efficiency was 6%.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0730-2312
    Keywords: giant cell tumor of bone ; MCP-1 ; TGF-β ; CD68+ ; chemotaxis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Giant cell tumor of bone (GCT) is one of a few neoplasms in which the macrophage/osteoclast precursor cells and osteoclast-like giant cells infiltrate the tumor mass. Monocyte chemoattractant protein 1 (MCP-1) is a potent chemotactic factor specific for monocytes. In search of relevant cytokines that may enhance the recruitment of these reactive cells, we evaluated the localization and regulation of MCP-1 mRNA and protein in GCT by using Northern blot analysis, in situ hybridization and immunohistochemistry. We also determined whether conditioned medium obtained from GCT cultures can recruit human peripheral blood monocytes (CD68+) in an in vitro chemotactic assay. Using Northern blot analysis, we detected the specific gene transcript for MCP-1 in all GCT samples tested. In situ hybridization and immunohistochemistry revealed that both MCP-1 gene transcript and protein were consistently present in the cytoplasm of stromal-like tumor cells of GCT. Treatment of mononuclear cells from GCT at third passage with TGF-β1 for 24 h increased the level of MCP-1 mRNA in a dose-dependent manner, with the maximum effect at 1 ng/ml. Conditioned media from GCT cultures promoted the chemotactic migration of CD68+ peripheral monocytes, an activity which was abolished by the addition of MCP-1 antibody to the conditioned medium. Thus, the results of this study suggest that recruitment of CD68+ macrophage-like cells may be due to the production MCP-1 by stromal-like tumor cells. These CD68+ cells may originate from peripheral blood and could have the capability of further differentiating into osteoclasts in the tumor. J. Cell. Biochem. 70:121-129, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 16 (1987), S. 47-56 
    ISSN: 0148-7280
    Keywords: spermatozoa ; oocytes ; sperm penetration ; pronuclear stage ; prometaphase stage ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A study of varying combinations of in vitro-aged sperm and in vivo-aged ova at 3 hr intervals from 0-24 hr resulted in failures at different steps of the fertilization process during in vitro fertilization of mouse ova. Significant decreases caused by sperm aging, ova aging, and sperm × ova aging interaction were found in sperm penetration. Pronuclear formation was not affected by sperm aging and was enhanced by ova aging, and there was a significant effect of sperm × ova aging interaction. Sperm aging significantly influenced the prometaphase stage of the fertilization process. Therefore, it is suggested that the detrimental fertilization effects resulting from aging gametes are due to different mechanisms in sperm and ova, that these mechanisms are affected at different times, and that they affect different steps in the fertilization process.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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