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We examined the hypoxic tolerance phenomenon in vitro. Brief exposure to hypoxia induced the production of basic fibroblast growth factor (bFGF) mRNA and protein in rat cortical neurons and protected them from hypoxic injury. Cortical neurons were cultured from 18th-day rat embryos in a serum-free medium and subjected to brief (4 h) and/or prolonged (24 h) hypoxia. Neuronal damage was assessed by quantifying lactate dehydrogenase (LDH) activity in the medium. After brief hypoxia, LDH release was identical to that of the controls, whereas prolonged hypoxia caused a significant increase in LDH release, indicating neuronal death. However, if brief hypoxia was applied 2 days prior to the prolonged hypoxia, no increase in LDH release was observed. The bFGF mRNA expression was assessed with Northern blot and protein immunoreactivity with Western blot analysis. The brief period of hypoxia caused a 2.5-fold increase in bFGF mRNA and considerable bFGF protein expression 1 day later, but prolonged hypoxia caused increase in the expression of bFGF mRNA at 2 days and no protein expression until 3 days after the start of the hypoxia. When cells were subjected to prolonged hypoxia 2 days after brief hypoxia, however, no increase in bFGF mRNA was observed, while bFGF protein was expressed continuously. We also observed that exogenously applied bFGF reduced neuronal injury produced by prolonged hypoxia. The results obtained with this model suggest that brief hypoxia induces bFGF protein and thus tolerance to subsequent lethal hypoxia. Basic FGF might play a role as a tolerance-associated factor in this process. Thus, an in vitro model is useful for assessing the response of cortical neurons to hypoxic stress and for researching new factors related to ischemic tolerance.  相似文献   
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It is shown that the electrical breakdown voltages of polycarbonate film/metal foil capacitors can be increased. This can be achieved by briefly exposing the metal foil in these spirally wound film foil sections to a low-pressure, low-temperature gas plasma. Exposure of tin/lead foil to a 96% CF4/4% O2 gas plasma for four min, for example, produced >500% increase in breakdown voltage of sealed polycarbonate capacitors  相似文献   
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Suggests that "manualized training" is most effective at increasing adherence to the technical procedures characterizing the treatment under scrutiny. There is minimal evidence that other skills associated with therapeutic competence are acquired or enhanced to the extent found with technical adherence. Drawing on findings from a study of manual-guided training of therapists in the techniques of brief therapy (H. H. Strupp and J. L. Binder, 1984), the author offers recommendations for improving therapy training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Surface properties of a number of commercial thermoplastic polymer films were investigated before and after brief exposures to RF induced, low temperature gas plasmas. Water wettability and adhesion of vapor deposited aluminum to thin films (8–12 micron) of polyethylene, polypropylene, polyester, polysulfone, polycarbonate, and polyvinylidene fluoride films were studied before and after treatments with oxygen, 96% CF4/4% O2, and helium plasmas. Treatment with oxygen plasmas showed the greatest change in water wettability for polyvinylidene fluoride and polypropylene films, while treatment with 96% CF4/4% O2 showed dramatic changes in wettability of polycarbonate, polysulfone, and polystyrene. Excellent adhesion of aluminium was found for polymers that had been previously exposed to gas plasmas.  相似文献   
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