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991.
992.
LIU Ling-mei ZHANG Mei LIU Yan-hong ZHOU Xin YE Fan HE Rui-bo LI Yu-ming 《园艺学报》2009,25(10):1892-1897
AIM: To investigate the effects of platelet glycoprotein Ⅱb/Ⅲa receptor inhibitor tirofiban on myocardial no-reflow and activation of NF-κB after acute ischemia/reperfusion in rats. METHODS: Male Wistar rats were randomized into sham operation group, control group and tirofiban treatment group. Control group and tirofiban group were subjected ischemia for 90 min by ligation of coronary artery after thoracotomy and subsequently reperfusion for 120 min to establish acute myocardial ischemia/reperfusion no-reflow models. Thioflavine S, Evans blue and triphenyltetra zolium chloride (TTC) staining were performed to evaluate the area of no-reflow (ANR), infracted area (IA) and risk area (RA) of the heart. Immunohistochemistry was used for semi-quantitative analysis of the expression of nuclear factor-κB p65 (NF-κB p65) protein in myocytes and arteriole. Activity of myeloperoxidase (MPO) and content of malondialdehyde (MDA) in risk area of the heart were detected by ultraviolet spectrophotometer. RESULTS: After 120 min for reperfusion, compared to sham group, the statistical differences of higher positive expression of NF-κB p65 in myocytes and arteriole, activity of MPO and content of MDA both in control and tirofiban group were observed. Compared to control group, lower positive expression of NF-κB p65 in myocyte and arteriole, activity of MPO and content of MDA in tirofiban group were found (P<0.05, P<0.01). A markedly reduced ANR and IA were observed in tirofiban group than those in control group (34.36%±6.04% vs 52.09%±6.89%, P<0.01; 80.41%±8.48% vs 90.13%±5.72%, P<0.05). CONCLUSION: After myocardial ischemia/reperfusion for 120 min, no-reflow phenomenon can be observed in rats. Tirofiban reduces the areas of anatomic no-reflow and infarction, inhibits the activation of NF-κB in myocyte and arteriole, and decreases the infiltration of neutrophils and release of oxygen free radicals. 相似文献
993.
994.
优秀学生由于受内外因的影响,也容易在思想上、行动上不自觉地离开既定方向,出现各种问题,而对于优秀学生的管教工作,往往是容易被班主任忽略的方面.对此,从辨证的角度来阐述了班主任如何加强对此类学生的管教工作,即既要看到优秀学生"好"的一面,也不能忽视"坏"的一面.正确地处理对此类学生"严"与"爱"的关系,是本文论述的关键所在. 相似文献
995.
周永军 《农业图书情报学刊》2004,16(8):31-33
从探讨电子公文的概念形成入手 ,分析了目前电子公文实际管理中存在的一些问题 ,并有针对性的提出了解决问题的对策 相似文献
996.
对模拟电路提出了一种基于小波与神经网络辅助式结合的故障诊断方法.该方法用小波变换作为模拟电路故障信号的预处理器,大大减少神经网络的输入数目,简化神经网络结构和减少它的训练时间,提高辨识故障能力.在介绍该故障诊断方法的基本原理后。给出了小波函数及故障特征选择的方法. 相似文献
997.
AIM: To investigate whether the bacterial DNA participates in SIRS and its possible mechanism. METHODS: Escherichia coli genomic DNA (EC DNA) was extracted and purified from Escherichia coli 25922 by alkaline lysis method. Mortality of mice challenged with EC DNA and the changes of TNF-α and IL-6 in rat serum were observed. ANA-1 cells were cultured in vitro, after the cells were stimulated by different concentrations of EC DNA and LPS, the level of TNF-α and IL-6 in supernatant were tested. Meanwhile,expression of TLR9 and TLR4 on cell surface was measured. Activation of NF-JB was also observed. RESULTS: The lethal effect of EC DNA on mice with an obvious dose-effect relationship was observed. The death happened within 24 hours. Calf thymus DNA and DNase I-treated EC DNA did not lead to mice to die. The changes of serum TNF-α and IL-6 in rats induced by EC DNA and LPS were similar, but TNF-α peak level of EC DNA group appeared 1 hour earlier than that of LPS group. In vitro, large amount of TNF-α and IL-6 were released from ANA-1 cells stimulated by EC DNA. High expression of TLR9 and TLR4 was observed on surfaces of THP-1 cells. In particularly, LPS induced strong activation of NFκB. The results suggested other pathway possibly took part in the signal transduction inducea by EC DNA. CONCLUSION: EC DNA has the abilities to lead to death of mice, andinduces serum TNF- αand IL- 6 level to increase in rats and ANA- 1 cells to release cytokines in vitro. High expression of TLR9 and TLR4, strong activation of NF- κB may be its importantmolecular mechanism, but other pathway probably exists to play an important role. 相似文献
998.
999.
1000.
针对目前济南今日摄影器材有限公司生产的磨光烫金一体机操作过程中存在安全隐患、自动化程度低等问题,提出两种方案对控制部分进行设计改造。详细介绍了两方案的工作原理和结构。试验结果表明,改造后的设备具有可靠的运行性能,安全性和自动化程度也得到较大提高。 相似文献