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有限域GF(2m)上基于基转换的正规基快速求逆方案
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作者 郑嘉青 刘吉强 赵勇 《计算机工程与应用》 CSCD 北大核心 2006年第21期45-47,共3页
有限域GF(2m)在椭圆曲线密码体制中有着非常重要的应用,密码体制的整体效率大部分取决于GF(2m)上的运算效率。该文给出了有限域GF(2m)上使用正规基表示时的一种快速求逆方案,该方案基于基转换技术,更改运算元素的表示基,采用多项式基的A... 有限域GF(2m)在椭圆曲线密码体制中有着非常重要的应用,密码体制的整体效率大部分取决于GF(2m)上的运算效率。该文给出了有限域GF(2m)上使用正规基表示时的一种快速求逆方案,该方案基于基转换技术,更改运算元素的表示基,采用多项式基的AI求逆算法进行运算。实验表明,此方案比普通的正规基求逆算法更加快速。 展开更多
关键词 GF(2m) 求逆 正规 多项式 基转换
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可穿戴纤维基能源转换器件研究进展
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作者 王昊煜 刘哲 +4 位作者 贺思佳 张健 杭格格 卫嬴 汪秀琛 《材料导报》 EI CAS CSCD 北大核心 2024年第3期203-212,共10页
随着智能可穿戴设备的普及,其能源供应问题愈加突出,一种绿色且高效的供能系统有待被研发。纤维基能源转换器件凭借着其优异的可集成性和宏观可调性,在柔性穿戴领域受到了越来越多的关注,有望成为解决新一代能源供给问题的有效方案。为... 随着智能可穿戴设备的普及,其能源供应问题愈加突出,一种绿色且高效的供能系统有待被研发。纤维基能源转换器件凭借着其优异的可集成性和宏观可调性,在柔性穿戴领域受到了越来越多的关注,有望成为解决新一代能源供给问题的有效方案。为进一步深化对纤维基能源转换方案的认识,本文主要回顾了压电、热电和磁电纤维基能源转换器件的最新研究与应用进展,重点讨论了压电纤维、热电纤维和磁电纤维的制备方法、性能分析和可穿戴应用,最后提出了纤维基能源转换器件在应用中所面临的问题与挑战,并对其未来的发展趋势进行了展望。 展开更多
关键词 纤维能源转换器件 压电纤维 热电纤维 磁电纤维 可穿戴
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抗纤软肝颗粒对肝纤维化大鼠肝脏基质转换及肝窦毛细血管化的影响 被引量:12
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作者 胡泰洪 葛娅 +4 位作者 张赤志 王晓昆 任星峰 唐瑛 朱清静 《中西医结合肝病杂志》 CAS 2003年第5期283-285,共3页
目的:观察抗纤软肝颗粒对实验性肝纤维化时肝脏基质金属蛋白酶-1(MMP-1)、金属蛋白酶组织抑制因子-1(TIMP-1)以及肝窦毛细血管化的影响,探讨其防治肝纤维化的作用。方法:250ml/L CCl_4经大鼠皮下注射制备肝纤维化模型并同时给予秋水仙... 目的:观察抗纤软肝颗粒对实验性肝纤维化时肝脏基质金属蛋白酶-1(MMP-1)、金属蛋白酶组织抑制因子-1(TIMP-1)以及肝窦毛细血管化的影响,探讨其防治肝纤维化的作用。方法:250ml/L CCl_4经大鼠皮下注射制备肝纤维化模型并同时给予秋水仙碱、小和大剂量抗纤软肝颗粒治疗,用光镜和电镜观察肝组织病理变化;免疫组织化学法检测肝组织Ⅰ、Ⅲ、Ⅳ型胶原、层粘蛋白(LM)原住杂交的方法检测MMP-1 mRNA、TIMP-1 mRNA。结果:抗纤软肝颗粒能促进MMP-1的表达(P<0.05),抑制TIMP-1的表达(P<0.01),促进Ⅰ、Ⅲ型胶原的降解(P<0.01);有效抑制Ⅳ型胶原、LM的生成和沉积(P<0.01),改善肝纤维化大鼠肝组织病理变化(P<0.01)。减轻肝窦毛细血管化程度。结论:抗纤软肝颗粒能促进MMP-1的表达,抑制TIMP-1的表达,促进胶原的降解,抑制肝窦毛细血管化的形成,从而产生抗肝纤维化的作用。 展开更多
关键词 抗纤软肝颗粒 肝纤维化 大鼠 肝脏转换 肝窦毛细血管化 金属质蛋白酶-1 金属质蛋白酶抑制因子-1
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非巯基血管紧张素转换酶抑制剂培哚普利 被引量:2
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作者 徐彬 杨惠娣 《中国临床药学杂志》 CAS 2001年第4期254-255,共2页
关键词 培哚普利 非巯血管紧张素转换酶抑制剂 药理学 药物动力学
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基于基空间转换的姿态人耳识别
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作者 王瑜 穆志纯 封筠 《郑州大学学报(工学版)》 CAS 2008年第1期31-34,共4页
人耳识别是近年来新兴起的一种生物特征识别技术,然而姿态问题一直是其难点问题之一,针对此问题提出了一种基于基空间转换的新方法.首先,利用主元分析和核主元分析方法得到姿态人耳图像和正侧面人耳图像的基空间,通过计算两种基空间之... 人耳识别是近年来新兴起的一种生物特征识别技术,然而姿态问题一直是其难点问题之一,针对此问题提出了一种基于基空间转换的新方法.首先,利用主元分析和核主元分析方法得到姿态人耳图像和正侧面人耳图像的基空间,通过计算两种基空间之间的线性转换关系求出姿态转换矩阵,然后将待测的姿态人耳图像特征集利用基空间姿态转换矩阵转变成正侧面人耳图像特征集,最后用支持向量机进行分类识别.实验结果表明,该方法与没有经过姿态转换的方法相比,识别率显著提高. 展开更多
关键词 空间转换 人耳识别 主元分析 核主元分析 姿态转换矩阵 支持向量机
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Wang-Ball基函数的对偶基及其应用 被引量:8
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作者 江平 邬弘毅 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2004年第4期454-458,共5页
对于n次Wang Ball曲线给出其对偶基 ,进而得到从Bernstein基到Wang
关键词 对偶 Wang-Ball Bernstein-Bezier 基转换公式 WANG-BALL曲线
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利用近震及远震转换波测定永清M4.3级地震的震源深度 被引量:2
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作者 朱冰清 曹井泉 +5 位作者 董一兵 谭毅培 赵黎明 臧翀 徐恒垒 倪四道 《大地测量与地球动力学》 CSCD 北大核心 2020年第3期291-298,共8页
根据近震沉积层基底界面转换波Sp震相和远震深度震相sP、pP的特征,对2018-02-12永清M4.3地震的震源深度进行分析,运用F-K波数与频率方法拟合近震理论波形、Teleseis方法拟合远震理论波形,并与实际波形对比,对震源深度进行测试。结果表明... 根据近震沉积层基底界面转换波Sp震相和远震深度震相sP、pP的特征,对2018-02-12永清M4.3地震的震源深度进行分析,运用F-K波数与频率方法拟合近震理论波形、Teleseis方法拟合远震理论波形,并与实际波形对比,对震源深度进行测试。结果表明,永清地震的震源深度为16~17 km,从发震位置和震源深度分析来看,此次地震发生在中上地壳,与区域内其他地震事件类似。 展开更多
关键词 永清地震 震源深度 沉积层转换 深度震相
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基于边缘智能优化的高性能模式转换器逆设计 被引量:1
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作者 杨子荣 田野 +3 位作者 廖俊鹏 康哲 张晓伟 金庆辉 《中国激光》 EI CAS CSCD 北大核心 2023年第18期292-299,共8页
模式转换器是实现模分复用技术(MDM)的关键部件。基于伴随法对器件边缘进行智能优化,从而在绝缘体上硅(SOI)平台上设计了高性能TE0-TE1模式转换器。经仿真验证,在中心波长1550 nm处,模式转换效率达99.6%,消光比达31.2 dB,而损耗仅为0.01... 模式转换器是实现模分复用技术(MDM)的关键部件。基于伴随法对器件边缘进行智能优化,从而在绝缘体上硅(SOI)平台上设计了高性能TE0-TE1模式转换器。经仿真验证,在中心波长1550 nm处,模式转换效率达99.6%,消光比达31.2 dB,而损耗仅为0.01 dB。在1500~1600 nm带宽范围内,TE0-TE1的转换效率保持在96.6%以上,消光比保持在15.7 dB以上,而损耗保持在0.14 dB以下。当器件尺寸变化在±20 nm以内时,器件在1550 nm处的转换效率保持在97.2%以上,消光比保持在16.5 dB以上,插入损耗维持在0.12 dB以下。在片上设计了TE1模式的测试装置,并利用商业流片对转换器进行制备。实验结果表明,在60 nm的带宽范围内,TE0-TE1转换器的转换效率保持在90%以上,插入损耗维持在0.4 dB以下。因此,所提出的转换器具有高转换效率、宽带宽、低插入损耗和高制作容差等特点,为高性能片上模式转换器的高效设计提供了新思路。 展开更多
关键词 集成光学 模式转换 模分复用 逆设计 伴随法
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B样条曲线最小二乘降阶方法 被引量:2
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作者 潘日晶 翁彬 《小型微型计算机系统》 CSCD 北大核心 2009年第2期295-301,共7页
提出一种新的B样条曲线降阶方法.该方法利用B样条基转换矩阵建立B样条曲线降阶的数学模型,将B样条曲线的降阶问题转化为求线性方程组的最小二乘解问题.该方法基于整体考虑不必对B样条曲线分段处理,步骤简单易实现;可一次降多阶,避免了... 提出一种新的B样条曲线降阶方法.该方法利用B样条基转换矩阵建立B样条曲线降阶的数学模型,将B样条曲线的降阶问题转化为求线性方程组的最小二乘解问题.该方法基于整体考虑不必对B样条曲线分段处理,步骤简单易实现;可一次降多阶,避免了重复一次降一阶运算引起的误差累积,而当仅降一阶时与基于控制顶点扰动的约束优化降阶方法的逼近效果一致;在降阶的同时可满足各种给定的端点约束条件,以满足实际应用中的各种要求. 展开更多
关键词 B样条曲线 降阶 B样条基转换矩阵 最小二乘法
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一种中国剩余定理权重预分配方法
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作者 马上 汪陈浩 +1 位作者 陈红艳 胡剑浩 《电子科技大学学报》 EI CAS CSCD 北大核心 2016年第2期161-167,共7页
中国剩余定理(CRT)是获取余数系统(RNS)权重信息的基本理论之一。该文提出了一种CRT的权重预分配方法,通过在一定约束条件下预分配CRT中的权重,使之运算结果保持不变,从而减小获取RNS权重信息或后向转换的复杂度。该方法使得CRT成为本... 中国剩余定理(CRT)是获取余数系统(RNS)权重信息的基本理论之一。该文提出了一种CRT的权重预分配方法,通过在一定约束条件下预分配CRT中的权重,使之运算结果保持不变,从而减小获取RNS权重信息或后向转换的复杂度。该方法使得CRT成为本文方法的一个特例,并可通过不同的预分配权重来获得不同的电路实现结构,较CRT方法具有更好的灵活性。此外,结合混合基转换(MRC)还给出了基于这种方法的一个后向转换应用实例。分析结果表明基于本文方法的RNS后向转换具有较好的灵活性,从而可优化RNS后向转换的实现结构。 展开更多
关键词 中国剩余定理 混合基转换 权重预分配 后向转换 余数系统
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Bézier曲线的升阶方法 被引量:2
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作者 马瑞海 邱泽阳 《黑龙江科技学院学报》 CAS 2010年第6期481-482,487,共3页
为了使伯恩斯坦基函数具有更多性质,更好地实现Bezier曲线升阶,把切比雪夫多项式转换到区间[0,1]上的正交函数。在区间[0,1]上,用该正交函数计算出转换矩阵M_n,并得到升阶矩阵T_(n,r),从而在切比雪夫多项式与伯恩斯坦基函数之间,建立转... 为了使伯恩斯坦基函数具有更多性质,更好地实现Bezier曲线升阶,把切比雪夫多项式转换到区间[0,1]上的正交函数。在区间[0,1]上,用该正交函数计算出转换矩阵M_n,并得到升阶矩阵T_(n,r),从而在切比雪夫多项式与伯恩斯坦基函数之间,建立转换矩阵。该方法能够有效地升阶Bezier曲线,使其在CAGD中应用更广泛。 展开更多
关键词 切比雪夫多项式 基转换 曲线升阶 连续性
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石灰石中碳酸钙含量测定方法的改进 被引量:2
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作者 王培红 《大氮肥》 CAS 2013年第6期427-429,共3页
GB/T 19281—2003中碳酸钙含量的测定方法存在分析时间长的弊端,为解决这一难题,经过大量试验总结出一种新分析方法,将原用烘箱烘至石灰石恒重再称样分析,改为用光波水分测定仪分析水分,且与碳酸钙含量分析同时进行,根据水分含量将湿基... GB/T 19281—2003中碳酸钙含量的测定方法存在分析时间长的弊端,为解决这一难题,经过大量试验总结出一种新分析方法,将原用烘箱烘至石灰石恒重再称样分析,改为用光波水分测定仪分析水分,且与碳酸钙含量分析同时进行,根据水分含量将湿基石灰石质量转换为干基石灰石质量再进行计算。分析结果准确度高,重现性好,分析时间缩短5.5h,克服了原方法的缺点,取得了令人满意的效果。 展开更多
关键词 碳酸钙含量 光波水分测定仪 湿基转换为干 缩短分析时间
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Emotional speaker recognition based on prosody transformation 被引量:1
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作者 宋鹏 赵力 邹采荣 《Journal of Southeast University(English Edition)》 EI CAS 2011年第4期357-360,共4页
A novel emotional speaker recognition system (ESRS) is proposed to compensate for emotion variability. First, the emotion recognition is adopted as a pre-processing part to classify the neutral and emotional speech.... A novel emotional speaker recognition system (ESRS) is proposed to compensate for emotion variability. First, the emotion recognition is adopted as a pre-processing part to classify the neutral and emotional speech. Then, the recognized emotion speech is adjusted by prosody modification. Different methods including Gaussian normalization, the Gaussian mixture model (GMM) and support vector regression (SVR) are adopted to define the mapping rules of F0s between emotional and neutral speech, and the average linear ratio is used for the duration modification. Finally, the modified emotional speech is employed for the speaker recognition. The experimental results show that the proposed ESRS can significantly improve the performance of emotional speaker recognition, and the identification rate (IR) is higher than that of the traditional recognition system. The emotional speech with F0 and duration modifications is closer to the neutral one. 展开更多
关键词 emotion recognition speaker recognition F0 transformation duration modification
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一类三角多项式样条曲线的升阶算法
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作者 冷丽娟 《现代电子技术》 2009年第14期152-155,共4页
曲线升阶是自由曲线曲面造型中的一项重要技术。升阶可以提高曲线的柔韧性,通过提高曲线次数,可以增加控制顶点,也可以提高曲线控制的自由度。同时,曲线升阶算法可以对不同CAD系统的产品数据交换带来方便。三角多项式样条曲线不仅继承了... 曲线升阶是自由曲线曲面造型中的一项重要技术。升阶可以提高曲线的柔韧性,通过提高曲线次数,可以增加控制顶点,也可以提高曲线控制的自由度。同时,曲线升阶算法可以对不同CAD系统的产品数据交换带来方便。三角多项式样条曲线不仅继承了B样条曲线的主要性质和优点,还能精确表示圆弧、椭圆弧和球面、椭球面等二次曲线的曲面,是一类重要的曲线曲面造型方法。在此,采用基转换方法以及基于广义逆的方法,并针对一类三角多项式样条曲线分别给出了升阶算法。 展开更多
关键词 升阶算法 基转换 广义逆 三角多项式样条
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Converted-wave diodic moveout and application in the land gas cloud area
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作者 张四海 李向阳 戴恒昌 《Applied Geophysics》 SCIE CSCD 2011年第3期171-180,239,共11页
PS converted-waves (C-waves) have been commonly used to image through gas clouds but the C-wave imaging may also be degraded by the diodic effect introduced by the gas cloud. It may be compensated for using a veloci... PS converted-waves (C-waves) have been commonly used to image through gas clouds but the C-wave imaging may also be degraded by the diodic effect introduced by the gas cloud. It may be compensated for using a velocity perturbation method which decouples the diodic moveout into two parts: the base velocity and the velocity perturbation. Gas clouds are widely distributed in the Sanhu area in the Qaidam basin of northwest China which is rich in natural gas. A land 2D3C seismic dataset is analyzed from the Sanhu area and significant diodic effects are observed in the data which harm the C-wave imaging. The diodic correction is applied to this data and the resultant C-wave imaging and the details of the reservoir structure are significantly improved. The diodic moveout plays an important role in working out the residu~ shear wave statics and the association of diodie correction and shear wave residual statics computation is a key step of C-wave high fidelity imaging in the gas cloud area. Finally, the new process workflow with diodic moveout is given. 展开更多
关键词 Diodic converted wave gas cloud base velocity PERTURBATION
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A Novel Multi-Stage Interpolation Filter Design Technique for High-Resolution Σ-Δ DAC 被引量:2
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作者 陈润 刘力源 李冬梅 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第11期1735-1741,共7页
This paper presents an efficient way to implement an interpolation filter in a 20bit ∑-△ DAC with an oversampling ratio of 128. A multistage structure is used to reduce the complexity of filter coefficients and the ... This paper presents an efficient way to implement an interpolation filter in a 20bit ∑-△ DAC with an oversampling ratio of 128. A multistage structure is used to reduce the complexity of filter coefficients and the fi- nite word length effect. A novel method based on mixed-radix number representation is proposed to realize a poly- phase multiplier-free half-band subfilter with a high resolution. This approach reduces the complexity of the con- trol system and saves chip area dramatically. The IC is realized in a standard 0.13μm CMOS process and the inter- polation filter occupies less than 0.63mm^2 . This realization has desirable properties of regularity with simple hard- ware devices which are suitable for VLSI and can be applied to many other high resolution data converters. 展开更多
关键词 interpolation filter mixed-radix MULTISTAGE ∑-△ DAC
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Molecular and functional comparisons of the vacuolar Na^+/H^+ exchangers originated from glycophytic and halophytic species 被引量:8
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作者 Jin-yao LI Xiao-wei HE +4 位作者 Li XU Jie ZHOU Ping WU Hui-xia SHOU Fu-chun ZHANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2008年第2期132-140,共9页
A novel vacuolar Na+/H+ exchanger, CgNHX1, was cloned from a halophytic species Chenopodium glaucum by using reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) techniq... A novel vacuolar Na+/H+ exchanger, CgNHX1, was cloned from a halophytic species Chenopodium glaucum by using reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) technique. Sequence alignment and phylogenetic analysis of 22 NHX genes from GenBank as well as the new CgNHX1 gene indicate that NHX genes shared a great degree of similarity, regardless of their glycophytic or halophytic origin. Expression of the CgNHX1 gene was induced by NaCl and peaked at 400 mmol/L NaCl. Overexpression of NHX1 genes in rice enhanced their tolerance to salt stress. However, there is no significant difference in salt tolerance among the transgenic rice plants overexpressing the NHX1 genes from either glycophytic or halophytic species. The Na+ content of both the wild type (WT) and transgenic plants increased when exposed to 50 and 100 mmol/L NaCl, and the Na+ concentration in transgenic plants was marginally higher than that of WT. Our data demonstrate that the overexpression of the NHX1 gene from either glycophytic or halophytic species resulted in the enhanced tolerance to salt stress at a similar level, suggesting that NHX gene per se might not be the reason accounting for the difference in salt tolerance between glycophytes and halophytes. 展开更多
关键词 NHX gene Rice transformation Salt stress TOLERANCE
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Detection of thiopurine s-methyltransferase mutations by template directed determinator in incorporation with fluorescence polarization (TDI-FP) 被引量:1
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作者 白玉杰 赵锦荣 +3 位作者 张文红 薛丽 郭晏海 闫小君 《Journal of Medical Colleges of PLA(China)》 CAS 2003年第6期F002-F002,392,393,共3页
Objective: To develop a new method for the detection of TPMT gene mutations and determine the frequencies of four TPMT alleles, TPMT *1, *3A , *3B and *3C in a healthy Chinese population. Methods: A TDI-FP assay syste... Objective: To develop a new method for the detection of TPMT gene mutations and determine the frequencies of four TPMT alleles, TPMT *1, *3A , *3B and *3C in a healthy Chinese population. Methods: A TDI-FP assay system was set up in out lab. To evaluate this system, 220 healthy individuals were analyzed for the polymorphic sites at positions 460(G→A)and 719(A→G)of the TPMP gene using our new TDI–FP method. Results: Three TPMP*3C(G 460→G 719) heterozygotes were identified, TPMP *3A and TPMP *3B were not found. All mutations were confirmed by conventional DNA sequencing analysis. Conclusion: TDI-FP method has proven to be very efficient as a rapid and accurate approach for TPMP genotyping. TPMP *3C was the only polymorphism identified in this clinical samples we have registered. 展开更多
关键词 thiopurine S-methyltransferase (TPMT) template- directed day-terminator incorporation (TDI) fluorescence polarization (FP) GENOTYPE polymorphism
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Correlation and prognostic significance of beta-galactoside alpha-2,6-sialyltransferase and serum monosialylated alpha-fetoprotein in hepatocellular carcinoma 被引量:4
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作者 Terence CW Poon Clarissa HS Chiu +5 位作者 Paul BS Lai Tony SK Mok Benny Zee Anthony TC Chan Joseph JY Sung Philip J Johnson 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第42期6701-6706,共6页
AIM: To investigate the correlation between tissue ST6Gal I and serum msAFP in HCC patients, and to investigate their prognostic significance. METHODS: Preoperative sera, paired tumorous and non-tumorous tissues wer... AIM: To investigate the correlation between tissue ST6Gal I and serum msAFP in HCC patients, and to investigate their prognostic significance. METHODS: Preoperative sera, paired tumorous and non-tumorous tissues were collected from 19 consecutive patients who had undergone surgical resection of HCC. ST6Gal I activities in the tissues were measured by an in vitro microsomal enzyme activity assay. The percentages of tumor-specific msAFP in the sera were also estimated by an isoelectric focusing-immunoblotting assay. RESULTS: The tumor ST6Gal I activity was negatively correlated with serum msAFP percentage (r = -0.53, P = 0.019). Both decreased tumor ST6Gal I activity and increased serum msAFP percentage were associated with poor tumor cell differentiation. Univariate analyses showed that both decreased tumor ST6Gal I activity (P = 0.028), increased serum msAFP percentage (P = 0.034) and poor tumor cell differentiation (P = 0.031)were associated with shorter overall survival. Multivariate analysis using the Cox regression model showed that the preoperative serum msAFP percentage (P = 0.022) and tumor cell differentiation status (P = 0.048) were independent prognostic indicators for patient overall survival. CONCLUSION: Our results indicate that the presence of msAFP in blood circulation is associated with a decreased activity of ST6Gal I activity in HCC. Both tissue ST6Gal I and serum msAFP are potential prognostic markers for patients with operable HCC. 展开更多
关键词 ALPHA-FETOPROTEIN Beta-galactoside alpha-2 6-sialyltransferase Hepatocellular carcinoma Patientsurvival Cell differentiation
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TIP30 regulates apoptosis-related genes in its apoptotic signal transduction pathway 被引量:22
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作者 MeiShi XiaZhang +3 位作者 PingWang Hong-WeiZhang Bai-HeZhang Meng-ChaoWu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第2期221-227,共7页
AIM: To investigate the role of TIP30 in apoptotic signal pathway in hepatoblastoma cells and to provide a basis for TIP30 as a gene therapy candidate in the regression of hepatoblastoma cells. METHODS: Apoptosis of h... AIM: To investigate the role of TIP30 in apoptotic signal pathway in hepatoblastoma cells and to provide a basis for TIP30 as a gene therapy candidate in the regression of hepatoblastoma cells. METHODS: Apoptosis of human hepatoblastoma cell lines HepG2 (p53 wild), Hep3B (p53 null) and PLC/RPF/5 (p53 mutant) infected with Ad-TIP30 (bearing a wild type human Tip30 gene) were analyzed and p53, Bax and Bcl-xl expression levels were compared among these cells. MTT assay, DNA fragmentation, in situ 3' end labeling of DNA, annexin-V FITC staining were used to detect cell death and apoptosis in cells at various time intervals subsequent to infection, and to determine whether TIP30 had an effect on the expression levels of some apoptosis-related gene products such as Bax, p53 and Bcl-xl. A similar time course experiment was performed by Western blotting. RESULTS: In MTT assay, the viability of HepG2 cells decreased significantly from 99.7% to 10% and displayed more massive cell death within 5-8 d than Hep3B and PLC/ RPF/5 cells, with their viability decreased from 97.8% to 44.3% and 98.1% to 50.4%, respectively. In annexin-V FITC assay, the percentage of apoptosis cells in HepG2 cells was two to three-fold higher than that in control cells (infected with Ad-GFP), two-fold higher than that in Hep3B cells and 1.4-fold higher than that in PLC/RPF/5 cells 36 h after infection, respectively. Moreover, in HepG2 cells, the p53 began to increase 6-8 h after infection, reaching a maximum level between 8 and 12 h after infection and then dropped. Bax showed a similar increase in the cells as p53 reached the maximum at 8-12 h and subsequently decreased. Interestingly, Bcl-xl protein levels were down regulated during 24 to 36 h after Ad-TIP30 infection. In contrast, ectopic expression of TIP30 in Hep3B and PLC/ RPF/5 cells had no effect on the regulation of Bax expression, but had an effect on Bcl-xl levels. In comparison with HepG2 cells, these data suggested that up-regulation of p53 levels by TIP30 might be a pre-requisite for Bax and Bax/Bcl-xl ratio increase. We hypothesied that TIP30 might regulate Bax gene partly through p53, which sensitizes cells to apoptosis by involving a p53 apoptosis signal transduction pathway. CONCLUSION: TIP30 plays an important role in predisposing hepatoblastoma cells to apoptosis through regulating expression levels of these genes. Ad-TIP30 carrying exogenous TIP30-anti-tumor genes may be regarded as a potential candidate for the treatment of hepatocellular carcinoma. 展开更多
关键词 HEPATOBLASTOMA TIP30 APOPTOSIS Signa transduction
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