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김경원,윤정구 대한미생물학회 1988 大韓微生物學會誌 Vol.23 No.1
Non-specific cellular immunity may play an important role in the immune defense mechanism against tumors and has recently become of great interest to many researchers. Among the effector cells involved in non-specific cellular immune reactions, natural killer(NK) cells and antibody dependent cell-mediated cytotoxicity(ADCC) effector cells are the principal targets in many of the investigations studying the hosts immune defense aginst tumors. In general most chemotherapeutic agents are known to depress host immune functions. However, such an effect in non-specific cellular immunity particulary on NK cell and ADCC activities has not been fully determined. In this report, the effects of 5-fluorouracil(5-FU) and adriamycin(ADM), which are widely used for the chemotherapy of human cancer, on mouse NK and ADCC activities were studied. Adult ICR mice were injected with either one of the drugs or a combination of them and then at given interval, splenocytes were collected. NK and ADCC activities were measured in vitro using a 4hr ^(51)Cr release assay employing YAC-1 and L1210 target cells respectively. The following results were obtained. 1, The administration of different doses of 5-FU or ADM either alone or in combination resulted in a dose-dependent inhibition of NK activity 48 hours post injection. In these experiments, the doses which showed the most significant inhibition were 12.0mg/ml and 1.2mg/ml or greater for 5-FU and ADM respectively. No difference in NK activity was observed between mice treated with the drugs in combination. In contrast, assays of AD- CC activity in splenocytes from the same mice showed no appreciable change in the level of cytotoxicity. 2. Kinetic studies revealed t4at splenocytes from mice treated with a single dose of 5-FU (12mg/kg) or ADM(1.2mg/kg) alone or in combination showed significantly decreased levels of NK activity 48 72 hours after treatment. Thereafter NK activity progressively increased and reacked the level of the controls at 7 days. Again, no significant changes in ADCC activity were observed in these experiments. 3. Splenocytes from mice treated 48 hours previously with the drugs significantly suppressed the NK activity of normal mice. 4. Futhermore, these splenacytes had an impaired in-vitro production of interleukin-2 as compared to those from normal controls. In conclusion, mice treated with 5-FU or ADM either alone or in combination, exhibited significantly depressed NK activities 2 3 days after treatment, but the level of ADCC activity was not effected. This suggest that NK-suppressing mechanisms which involve the appearance and activation of suppressor cells and which impair the production of interleukin-2, may de- velope following chemotherapy.
Effect of excimer laser annealing on the properties of ZnO thin film prepared by sol-gel method
김경원,김상식,이상렬 한국물리학회 2012 Current Applied Physics Vol.12 No.2
Pristine ZnO thin films have been deposited with zinc acetate [Zn(CH3COO)2], mono-ethanolamine (stabilizer), and isopropanol solutions by sol-gel method. After deposition, pristine ZnO thin films have been irradiated by excimer laser (l ¼ 248, KrF) source with energy density of 50 mJ/cm2 for 30 sec. The effect of excimer laser annealing on the optical and structural properties of ZnO thin films are investigated by photoluminescence and field emission scanning electron microscope. As-grown ZnO thin films show a huge peak of visible region and a wide full width at half maximum (FWHM) of UV region due to low quality with amorphous ZnO thin films. After KrF excimer laser annealing, ZnO thin films show intense near-band-edge (NBE) emission and weak deep-level emission. The optically improved pristine ZnO thin films have demonstrated that excimer laser annealing is novel treatment process at room temperature.