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Effect of Helicobacterpyloriinfection on Bax protein expression in patients with gastric precancerous lesions 被引量:3
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作者 Hai-Feng liu wei-wen liu +1 位作者 Guo-An Wang Xiao-Chun Teng 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第37期5899-5901,共3页
AIM: To investigate the effect of Helicobacter pylori (H pylon) infection on Bax protein expression, and explore the role of Hpyloriin gastric carcinogenesis. METHODS: Hpyloriwas assessed by rapid urease test and ... AIM: To investigate the effect of Helicobacter pylori (H pylon) infection on Bax protein expression, and explore the role of Hpyloriin gastric carcinogenesis. METHODS: Hpyloriwas assessed by rapid urease test and Warthin-Starry method, and expression of Bax protein was examined immunohistochemically in 72 patients with pre-malignant lesions. RESULTS: Bax protein was differently expressed in intestinal metaplasia and gastric dysplasia, and showed 63.99% positivity. The positivity of Bax protein expression in Hpylori-positive gastric precancerous lesions (72.3%) was significantly higher than that in H pylori-negative gastric precancerous lesions (48.0%, x^2= 4.191, P〈0.05). Hpyloriinfection was well correlated with the expression of Bax protein in gastric precancerous lesions (r= 0.978, P〈0.01). After eradication of H pylori, the positivity of Bax protein expression significantly decreased in Hpylori-positive gastric precancerous lesions (x^2 = 5.506, P〈0.05). In the persisting H pylori-infected patients, the positivity of Bax protein expression was not changed. CONCLUSION: H pyloriinfection may be involved in the upregulation of Bax gene, which might be one of the mechanisms of Hpyloriinfection-induced gastric epithelial cell apoptosis. Hpylorimight act as a tumor promoter in the genesis of gastric carcinoma and eradication of Hpylori could inhibit gastric carcinogenesis. 展开更多
关键词 Helicobacter pylori Bax protein Gastric precancerous lesions
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用于制备优质单壁碳纳米管管束的MgO负载Fe_3O_4纳米粒子的合成(英文) 被引量:2
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作者 wei-wen liu Azizan Aziz +2 位作者 Siang-Piao Chai Abdul Rahman Mohamed Ching-Thian Tye 《新型炭材料》 SCIE EI CAS CSCD 北大核心 2011年第4期255-261,共7页
采用沉淀方法制备了直径分布狭窄的均匀Fe3O4纳米颗粒。Fe3O4纳粒形体几近一致,平均粒径为10.33nm±2.99nm(平均粒径±标准偏差)。在超声作用下将MgO纳米颗粒分散在一定量Fe3O4纳米颗粒的水溶液中获得MgO负载Fe3O4的纳米颗粒。... 采用沉淀方法制备了直径分布狭窄的均匀Fe3O4纳米颗粒。Fe3O4纳粒形体几近一致,平均粒径为10.33nm±2.99nm(平均粒径±标准偏差)。在超声作用下将MgO纳米颗粒分散在一定量Fe3O4纳米颗粒的水溶液中获得MgO负载Fe3O4的纳米颗粒。以甲烷为碳源,Fe3O4/MgO为催化剂,经化学气相沉积,在Fe3O4纳粒上制得了大量直径近乎均匀的单壁碳纳米管(SWCNTs)束。TEM显示:SWCNTs的平均直径1.22nm。热重分析显示:样品在400℃~600℃温度区间失重量约19%。拉曼光谱显示:SWCNTs的ID/IG的强度比为0.03,表明采用Fe3O4/MgO催化剂可制得高石墨化程度的单壁碳纳米管。 展开更多
关键词 单壁碳纳米管 化学气相沉积 电子显微镜 拉曼光谱
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Parameters optimization and nonlinearity analysis of grating eddy current displacement sensor using neural network and genetic algorithm 被引量:17
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作者 Hong-li QI Hui ZHAO +1 位作者 wei-wen liu Hai-bo ZHANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第8期1205-1212,共8页
A grating eddy current displacement sensor(GECDS) can be used in a watertight electronic transducer to realize long range displacement or position measurement with high accuracy in difficult industry conditions.The pa... A grating eddy current displacement sensor(GECDS) can be used in a watertight electronic transducer to realize long range displacement or position measurement with high accuracy in difficult industry conditions.The parameters optimization of the sensor is essential for economic and efficient production.This paper proposes a method to combine an artificial neural network(ANN) and a genetic algorithm(GA) for the sensor parameters optimization.A neural network model is developed to map the complex relationship between design parameters and the nonlinearity error of the GECDS,and then a GA is used in the optimization process to determine the design parameter values,resulting in a desired minimal nonlinearity error of about 0.11%.The calculated nonlinearity error is 0.25%.These results show that the proposed method performs well for the parameters optimization of the GECDS. 展开更多
关键词 Grating eddy current displacement sensor (GECDS) Artificial neural network (ANN) Genetic algorithm (GA) Parameters optimization Nonlinearity error
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Characteristics analysis and parameters optimization for the grating eddy current displacement sensor 被引量:4
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作者 Hong-li QI Hui ZHAO wei-wen liu 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第7期1029-1037,共9页
The grating eddy current displacement sensor (GECDS) for distance or position measurement used in watertight electronic calipers was described. The sensor relies on repetitive variation of inductance against displacem... The grating eddy current displacement sensor (GECDS) for distance or position measurement used in watertight electronic calipers was described. The sensor relies on repetitive variation of inductance against displacement caused by the change of coupling areas between moving coils and static reflectors. The investigations focused on setting up and utilizing a computer model of the 3D eddy current fields and geometry to analyze causes of the production of measurement blind areas, and to investigate effects of the sensor parameters, such as axial gap between coils and reflectors, reflector length and reflector width on characteristics of the sensor. Simulation results indicated that the sensor has the smallest nonlinearity error of 0.15%, which agrees well with the experimental results. 展开更多
关键词 Grating eddy current displacement sensor (GECDS) Watertight electronic calipers Parameters optimization NONLINEARITY
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