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CT机定位光标模体的开发与应用
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作者 韩忠成 张子剑 《中国计量》 2000年第7期35-35,共1页
关键词 CT机 定位光标 检测 定位光标 定位
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转录因子结合位点的计算分析方法 被引量:8
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作者 李婷婷 蒋博 +1 位作者 汪小我 张学工 《生物物理学报》 CAS CSCD 北大核心 2008年第5期334-347,共14页
基因组上众多基因和非编码转录体按照特定的规律有序地表达是细胞正常生命活动的基础。转录调控是基因表达调控的关键步骤,转录因子结合在基因启动子序列中的转录因子结合位点,启动基因的转录和控制基因的转录效率。分析转录因子结合位... 基因组上众多基因和非编码转录体按照特定的规律有序地表达是细胞正常生命活动的基础。转录调控是基因表达调控的关键步骤,转录因子结合在基因启动子序列中的转录因子结合位点,启动基因的转录和控制基因的转录效率。分析转录因子结合位点对研究基因调控系统有着重要意义,生物信息学在转录因子结合位点的研究中发挥着关键的作用。文章综述了分析蛋白质编码基因的转录因子结合位点的典型流程,总结了主要的算法、软件和资源,并简要评述了目前非编码RNA转录调控的研究现状。 展开更多
关键词 转录因子结合位点 识别 模体定位 非编码RNA转录调控 生物信息学
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提高放射治疗摆位精度 被引量:6
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作者 赵辉 赵文晖 +2 位作者 师芳 张晓智 罗伟 《现代肿瘤医学》 CAS 2013年第6期1351-1353,共3页
目的:探讨放射治疗时如何改进定位器械和摆位方式,在不增加摆位程序的条件下提高摆位治疗的精度。方法:对22位胸腹肿瘤患者分别用热塑定位体模和自己研发的定位辅助器械,进行定位和复位。在20次治疗摆位时,两种模型各用10次,对每一位患... 目的:探讨放射治疗时如何改进定位器械和摆位方式,在不增加摆位程序的条件下提高摆位治疗的精度。方法:对22位胸腹肿瘤患者分别用热塑定位体模和自己研发的定位辅助器械,进行定位和复位。在20次治疗摆位时,两种模型各用10次,对每一位患者采用相同的摆位条件,摆位后用CBCT在相同条件下采集图像信息,通过XVI系统采用骨模式在相同条件下和参考图像进行匹配,记录数据,观察两种摆位方式哪种精度更高。结果:X,Y,Z三个方向的误差使用辅助器械后治疗精度均有很大提高。结论:采用自己研发的辅助器械后,摆位精度更高。 展开更多
关键词 放射治疗 摆位 热塑定位 定位辅助器械 精度
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LOCALIZATION OF OBJECT (SPINE) IN MEDICAL IMAGE USING ACTIVE SHAPE MODELS 被引量:2
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作者 徐涛 蔡宇新 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期211-217,共7页
Active shape models (ASM), consisting of a shape model and a local gray-level appearance model, can be used to locate the objects in images. In original ASM scheme, the model of object′s gray-level variations is base... Active shape models (ASM), consisting of a shape model and a local gray-level appearance model, can be used to locate the objects in images. In original ASM scheme, the model of object′s gray-level variations is based on the assumption of one-dimensional sampling and searching method. In this work a new way to model the gray-level appearance of the objects is explored, using a two-dimensional sampling and searching technique in a rectangular area around each landmark of object shape. The ASM based on this improvement is compared with the original ASM on an identical medical image set for task of spine localization. Experiments demonstrate that the method produces significantly fast, effective, accurate results for spine localization in medical images. 展开更多
关键词 object localization active shape models (ASM) gray-level appearance model principal component analysis SPINE
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The Anti—tumor Effects of an Anti—CD71 Chimeric Antibody in Vitro and Its Distribution in a Tumor Xenograft Model 被引量:2
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作者 YANGDaofeng WANGShuo 《The Chinese-German Journal of Clinical Oncology》 CAS 2002年第2期109-112,共4页
Objective To investigate the anti-tumor effects in vitro and in vivo distribution of the human/murine chimeric antibody (D2C). Methods The CD71 positive target cells (K562, GEM and SMMC7721) and the effector cells, fr... Objective To investigate the anti-tumor effects in vitro and in vivo distribution of the human/murine chimeric antibody (D2C). Methods The CD71 positive target cells (K562, GEM and SMMC7721) and the effector cells, freshly isolated human PBMC, with the ratio of target cells to effector cells 1:50, were incubated in various dilutions of D2C antibody ( Ab) . Antibody dependent cytotoxicity (AD-CC) was tested by using an LDH-release assay. Instead of effector cells, complement was added to the target cells (GEM, SMMC-7721) with various dilutions of D2C Ab. A method of counting death cells was used in complement dependent cytotoxicity (CDC) assay. Tumor localization and distribution of the chimeric antibody (D2C) were observed by labeling the chimeric Ab with radioiodine(131I) and injecting it into nude mice (Balb/c nu/nu) transplanted with human hepatocellular carcinoma cells (SMMC-7721).Results A significant ADCC was observed with the increased concentration of the D2C Ab. Cytolysis of CD71-positive target cells by the D2C Ab was found in the presence of fresh rabbit complement. Labeled D2C administered by intraperitoneal as well as tumor regional injection, was visualized by SPECT. The distribution of D2C Ab in murine organs and tissues showed that non-specific binding was lower following tumor regional administration than when the antibody was administered by an intraperitoneal injection. The human/murine chimeric antibody (D2C) has in vitro anti-tumor effects and can exert its effects in specific tumor localization. Its distribution and local effects in vivo can be detected by radioimmunoimaging.Conclusion CD71 human/murine chimeric antibody showed marked killing of tumor cells in vitro, and specific recognition and high affinity binding to tumor tissue in vivo 展开更多
关键词 CD71 human/murine chimeric antibody ADCC CDC
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基于线性模型的牙科曲面断层X射线定位方法 被引量:1
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作者 贺玉鑫 唐智睿 +1 位作者 唐遥磊 舒明明 《中国辐射卫生》 2022年第6期694-697,共4页
目的设计基于线性模型的定位模体,解决牙科曲面断层X射线摄影装置快速定位有用线束的问题。方法应用解一次线性方程的数学原理,将二维平面坐标映射至牙科曲面断层X射线摄影装置探测器平面,通过X射线在探测器平面成像确定纵坐标值而确定... 目的设计基于线性模型的定位模体,解决牙科曲面断层X射线摄影装置快速定位有用线束的问题。方法应用解一次线性方程的数学原理,将二维平面坐标映射至牙科曲面断层X射线摄影装置探测器平面,通过X射线在探测器平面成像确定纵坐标值而确定横坐标位置,最终确定有用线束在探测器平面所在位置。结果通过分析应用模型后拍摄的影像,确定其影像纵向图像特征,最终定位的有用线束在探测器平面所在位置准确;对比模体法与胶片法检测结果,模体法定位结果均落在胶片法影像中心90%区域内,经Shapiro-Wilk正态性检验及配对样本t检验,2种方法的定位结果差异无统计学意义(P>0.05)。结论对于窄束类设备,基于线性模型方法设计的定位模体可快速有效的定位有用线束在探测器平面所在位置,可有效代替胶片法。 展开更多
关键词 线性 牙科 曲面断层 定位
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Modeling, identification and compensation for geometric errors of laser annealing table 被引量:1
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作者 李殿新 张建富 +1 位作者 张云亮 冯平法 《Journal of Central South University》 SCIE EI CAS 2014年第3期904-911,共8页
In order to improve the process precision of an XY laser annealing table, a geometric error modeling, and an identification and compensation method were proposed. Based on multi-body system theory, a geometric error m... In order to improve the process precision of an XY laser annealing table, a geometric error modeling, and an identification and compensation method were proposed. Based on multi-body system theory, a geometric error model for the laser annealing table was established. It supports the identification of 7 geometric errors affecting the annealing accuracy. An original identification method was presented to recognize these geometric errors. Positioning errors of 5 lines in the workspace were measured by a laser interferometer, and the 7 geometric errors were identified by the proposed algorithm. Finally, a software-based error compensation method was adopted, and a compensation mechanism was developed in a postprocessor based on LabVIEW. The identified geometric errors can be compensated by converting ideal NC codes to actual NC codes. A validation experiment has been conducted on the laser annealing table, and the results indicate that positioning errors of two validation lines decreased from ±37 μm and ±33 μm to ±5 μm and ±4.5 μm, respectively. The geometric error modeling, identification and compensation method presented in this work can be straightforwardly extended to any configurations of 2-dimensional worktable. 展开更多
关键词 geometric error error modeling error measurement error identification error compensation laser annealing table
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Assessment Model of Atmosphere Transmitting Influence on High-resolution Airborne SAR Stereo Positioning
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作者 ZHENG Zhaoqing PANG Lei CHEN Xuexing 《Chinese Geographical Science》 SCIE CSCD 2008年第4期369-373,共5页
The influence derived from atmosphere transmitting of radar wave, in the application of high-resolution airborne Synthetic Aperture Radar (SAR) stereo positioning, may produce some phase errors, and eventually be intr... The influence derived from atmosphere transmitting of radar wave, in the application of high-resolution airborne Synthetic Aperture Radar (SAR) stereo positioning, may produce some phase errors, and eventually be introduced into positioning model. This paper described the principle of airborne SAR stereo positioning and the error sources of stereo positioning accuracy that arose from atmosphere transmitting, established a corresponding assess- ment model of atmosphere transmitting influence, and testified the model and the assessment principle taking the 1-m resolution airborne SAR images of Zigong City, Sichuan Province in China, as the test dataset. The test result has proved that the assessment model is reliable and reasonable. And, it has shown that the phase error arisen from time delay is the main error source during the atmosphere transmitting, which has much more influences on cross-track di- rection and introduces a stereo positioning error of about eight meters, but less on the along-track direction. 展开更多
关键词 airborne SAR atmosphere transmitting assessment model radar wave stereo positioning
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