目的:确认水辅助肠镜和传统注气肠镜在患者的耐受度、成功率、操作时间、病变检出率及患者的重复检查率等方面的优劣程度,对临床行结肠镜检查进行指导。方法:通过对Medline,Embase,Pub Med,Cochrane Central Trials,中国期刊全文数据库(...目的:确认水辅助肠镜和传统注气肠镜在患者的耐受度、成功率、操作时间、病变检出率及患者的重复检查率等方面的优劣程度,对临床行结肠镜检查进行指导。方法:通过对Medline,Embase,Pub Med,Cochrane Central Trials,中国期刊全文数据库(CNKI)和中国生物医学文献数据库(CBM)等数据库的检索(时间截止于2014年9月),两名作者对纳入文献进行了质量评价和数据提取,争议的部分,由第三方裁定,所有的统计分析都根据是否存在异质性而分别运用了随机效应模型及固定效应模型使用STATA软件完成的。结果:包括2312名患者的10篇研究文献被纳入,结果显示:水辅助肠镜的达盲时间(1.646;95%CI:1.219~2.073;P=0.000)及总操作时间(2.111;95%CI:1.508~2.713;P=0.000)比注气肠镜更长,达盲率(OR:0.868;95%CI:0.368~2.047;P=0.747)及息肉检出率(OR:1.084;95%CI:0.622~1.889;P=0.776)两者相当;而水辅助肠镜的疼痛评分(-1.489;95%CI:-1.893^-1.086;P=0.000)和麻醉镇静率更低(OR:0.421;95%CI:0.328~0.539;P=0.000);腺瘤检出率(OR:1.239;95%CI:1.034-1.486;P=0.020)及患者的重复检查率(OR:2.298;95%CI:1.614!3.271;P=0.000)更高。结论:水辅助肠镜虽然时间更长,但在减少患者痛苦、腺瘤检出率以及患者的随访复查等方面优于传统注气肠镜,是一种更舒适及高效的方法。展开更多
To investigate the distribution and velocity attributes of gas hydrates in the northern continental slope of South China Sea, Guangzhou Marine Geological Survey conducted four-component （4C） ocean-bottom seismometer...To investigate the distribution and velocity attributes of gas hydrates in the northern continental slope of South China Sea, Guangzhou Marine Geological Survey conducted four-component （4C） ocean-bottom seismometer （OBS） surveys. A case study is presented to show the results of acquiring and processing OBS data for detecting gas hydrates. Key processing steps such as repositioning, reorientation, PZ summation, and mirror imaging are discussed. Repositioning and reorientation find the correct location and direction of nodes. PZ summation matches P- and Z-components and sums them to separate upgoing and downgoing waves. Upgoing waves are used in conventional imaging, whereas downgoing waves are used in mirror imaging. Mirror imaging uses the energy of the receiver ghost reflection to improve the illumination of shallow structures, where gas hydrates and the associated bottom-simulating reflections （BSRs） are located. We developed a new method of velocity analysis using mirror imaging. The proposed method is based on velocity scanning and iterative prestack time migration. The final imaging results are promising. When combined with the derived velocity field, we can characterize the BSR and shallow structures; hence, we conclude that using 4C OBS can reveal the distribution and velocity attributes of gas hydrates.展开更多
文摘目的:确认水辅助肠镜和传统注气肠镜在患者的耐受度、成功率、操作时间、病变检出率及患者的重复检查率等方面的优劣程度,对临床行结肠镜检查进行指导。方法:通过对Medline,Embase,Pub Med,Cochrane Central Trials,中国期刊全文数据库(CNKI)和中国生物医学文献数据库(CBM)等数据库的检索(时间截止于2014年9月),两名作者对纳入文献进行了质量评价和数据提取,争议的部分,由第三方裁定,所有的统计分析都根据是否存在异质性而分别运用了随机效应模型及固定效应模型使用STATA软件完成的。结果:包括2312名患者的10篇研究文献被纳入,结果显示:水辅助肠镜的达盲时间(1.646;95%CI:1.219~2.073;P=0.000)及总操作时间(2.111;95%CI:1.508~2.713;P=0.000)比注气肠镜更长,达盲率(OR:0.868;95%CI:0.368~2.047;P=0.747)及息肉检出率(OR:1.084;95%CI:0.622~1.889;P=0.776)两者相当;而水辅助肠镜的疼痛评分(-1.489;95%CI:-1.893^-1.086;P=0.000)和麻醉镇静率更低(OR:0.421;95%CI:0.328~0.539;P=0.000);腺瘤检出率(OR:1.239;95%CI:1.034-1.486;P=0.020)及患者的重复检查率(OR:2.298;95%CI:1.614!3.271;P=0.000)更高。结论:水辅助肠镜虽然时间更长,但在减少患者痛苦、腺瘤检出率以及患者的随访复查等方面优于传统注气肠镜,是一种更舒适及高效的方法。
基金supported by the National Hi-tech Research and Development Program of China(863 Program)(Grant No.2013AA092501)the China Geological Survey Projects(Grant Nos.GZH201100303 and GZH201100305)
文摘To investigate the distribution and velocity attributes of gas hydrates in the northern continental slope of South China Sea, Guangzhou Marine Geological Survey conducted four-component （4C） ocean-bottom seismometer （OBS） surveys. A case study is presented to show the results of acquiring and processing OBS data for detecting gas hydrates. Key processing steps such as repositioning, reorientation, PZ summation, and mirror imaging are discussed. Repositioning and reorientation find the correct location and direction of nodes. PZ summation matches P- and Z-components and sums them to separate upgoing and downgoing waves. Upgoing waves are used in conventional imaging, whereas downgoing waves are used in mirror imaging. Mirror imaging uses the energy of the receiver ghost reflection to improve the illumination of shallow structures, where gas hydrates and the associated bottom-simulating reflections （BSRs） are located. We developed a new method of velocity analysis using mirror imaging. The proposed method is based on velocity scanning and iterative prestack time migration. The final imaging results are promising. When combined with the derived velocity field, we can characterize the BSR and shallow structures; hence, we conclude that using 4C OBS can reveal the distribution and velocity attributes of gas hydrates.
