LR 1200型钢轨闪光焊机是为铁路轨道实现无缝线路而设计的专用设备。文中介绍了该专机的主要组成部分—焊机机头的设计及控制系统的设计。焊机机头采用了对中方便,结构紧凑的悬挂式结构;控制系统采用SLC5/03系列可编程序控制器,具有稳...LR 1200型钢轨闪光焊机是为铁路轨道实现无缝线路而设计的专用设备。文中介绍了该专机的主要组成部分—焊机机头的设计及控制系统的设计。焊机机头采用了对中方便,结构紧凑的悬挂式结构;控制系统采用SLC5/03系列可编程序控制器,具有稳定、可扩展、功能化编程和使用方便等特点。展开更多
Objective： To compare the efficacy between stereotactic radiotherapy （SRT） and intracavitary brachytherapy （brachytherapy） in residual tumor of nasopharyngeal carcinoma （NPC） after treating with conventional ex...Objective： To compare the efficacy between stereotactic radiotherapy （SRT） and intracavitary brachytherapy （brachytherapy） in residual tumor of nasopharyngeal carcinoma （NPC） after treating with conventional external beam radiotherapy. Methods： 60 patients with residual tumor of NPC after radical external beam radiotherapy （range 68 to 72 Gy） were randomized into SRT group （27 patients） and brachytherapy group （33 patients）. Patients in SRT group received boost treatment of 10-20 Gy, 2-3 fractions, once every other day; patients in brachytherapy group were treated with boost 10-20 Gy, 5 Gy per fraction, twice a week. Results： Efficacy in the near future： in SRT group, the complete recession （CR）, partial recession （PR） and no change （NC） rates were 77.8% （21/27）, 18.5% （5/27）, 3.7% （1/27）, respectively and the efficacy rate was 96.3% （CR ＋ PR）; in brachytherapy group： the CR, PR and NC rates were 75.8% （25/33）, 18.2% （6/33）, 6.1% （2/33）, respectively and the efficacy rate was 93.9% （CR ＋ PR）. The efficacy rates of the above two groups were compared （x^2 = 0.032, P 〉 0.05）. Long term efficacy： in SRT group, 1-year and 3-year survival rates were 96.3%, 66.5% respectively and the median live time was 48 months; in brachytherapy group： 1-year and 3-year survival rates were 93.9%, 60.2% respectively and the median live time was 46 months. The survival rates of two groups were compared （x^2 = 0.172, P 〉 0.05）. Conclusion： Both boost techniques of SRT and brachytherapy had elevated efficacy in patients with residual tumor of NPC and there was no obvious difference between the efficacy of the near and long term in SRT and brachytherapy group.展开更多
文摘Objective： To compare the efficacy between stereotactic radiotherapy （SRT） and intracavitary brachytherapy （brachytherapy） in residual tumor of nasopharyngeal carcinoma （NPC） after treating with conventional external beam radiotherapy. Methods： 60 patients with residual tumor of NPC after radical external beam radiotherapy （range 68 to 72 Gy） were randomized into SRT group （27 patients） and brachytherapy group （33 patients）. Patients in SRT group received boost treatment of 10-20 Gy, 2-3 fractions, once every other day; patients in brachytherapy group were treated with boost 10-20 Gy, 5 Gy per fraction, twice a week. Results： Efficacy in the near future： in SRT group, the complete recession （CR）, partial recession （PR） and no change （NC） rates were 77.8% （21/27）, 18.5% （5/27）, 3.7% （1/27）, respectively and the efficacy rate was 96.3% （CR ＋ PR）; in brachytherapy group： the CR, PR and NC rates were 75.8% （25/33）, 18.2% （6/33）, 6.1% （2/33）, respectively and the efficacy rate was 93.9% （CR ＋ PR）. The efficacy rates of the above two groups were compared （x^2 = 0.032, P 〉 0.05）. Long term efficacy： in SRT group, 1-year and 3-year survival rates were 96.3%, 66.5% respectively and the median live time was 48 months; in brachytherapy group： 1-year and 3-year survival rates were 93.9%, 60.2% respectively and the median live time was 46 months. The survival rates of two groups were compared （x^2 = 0.172, P 〉 0.05）. Conclusion： Both boost techniques of SRT and brachytherapy had elevated efficacy in patients with residual tumor of NPC and there was no obvious difference between the efficacy of the near and long term in SRT and brachytherapy group.
