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Chemoprevention of tea on colorectal cancer induced by dimethylhydrazine in Wistar rats 被引量:21
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作者 Jia XD Han C 《World Journal of Gastroenterology》 SCIE CAS CSCD 2000年第5期699-703,共5页
AIM To investigate the chemopreventiveeffects of green tea and tea pigment on 1,2-dimethylhydrazine(DMH)-induced rat colorectalcarcinogenesis.METHODS Male weaning Wistar rats wererandomly allocated into four groups.Ra... AIM To investigate the chemopreventiveeffects of green tea and tea pigment on 1,2-dimethylhydrazine(DMH)-induced rat colorectalcarcinogenesis.METHODS Male weaning Wistar rats wererandomly allocated into four groups.Rats in thepositive control group were given s.c.injectionof DMH,once a week for ten weeks;rats in tea-treated groups,with the same DMH treatment asin the positive group,received 2% green tea and0.1% tea pigments;rats in the negative controlgroup were given s.c.injection of the samevolume of saline as well as DMH in the positivegroup.Animals were sacrified and necropsied atthe end of week 16 and week 32.RESULTS Aberrant cryptic foci(ACF)wereformed in animals in DMH-treated groups at theend of week 16.Compared to the DMH group,green tea and tea pigments groups had less ACF(148.25 and 204.25,respectively,P【0.01).Atthe end of week 32,all rats in DMH groupdeveloped large intestinal tumors.The resultsalso showed that DMH increased labeling index(LI)of proliferating cell nuclear antigen(PCNA)of intestinal mucosa and the expression of ras-p21.However,in the tea-treated groups,PCNA-LI was significantly reduced as compared withthe positive control group(36.63 and 40.36 inthe green tea group and tea pigment group,respectively,at the end of the experiment,P【0.01).ras-p21 expression was alsosignificantly reduced(2.07 and 2.36 in the colontumors of rats in the green tea group and teapigments group,respectively at the end of theexperiment,P【0.01).Furthermore,green tea and tea pigment inhibited the expression of Bcl-2protein(2,5,1,0 and 2,4,1,0,respectively,at the end of the experiment P【0.01),andinduced expression of Bax protein(0,1,3,4and 0,1,4,3,respectively,P【0.01).CONCLUSION Chinese green tea drinkinginhibited ACF and colonic tumors formation inrats,which showed that tea had a significantchemopreventive effect on DMH-inducedcolorectal carcinogenesis.Such effects may bedue to suppression of cell proliferation andinduction of apoptosis in the intestinal crypts. 展开更多
关键词 colorectal neoplasms DIMETHYLHYDRAZINE TEA apoptosis aberant CRYPT FOCI rats PROLIFERATING cell nuclear antigen CHEMOPREVENTION
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基于Saber的反激式开关电源仿真 被引量:3
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作者 陈航新 《科技与生活》 2010年第8期20-21,共2页
通过使用Saber软件,搭建电路级模型,仿真研究反激式开关电源。分析反激式开关电源原理,并与试验样机做对比,体现仿真对设计的指导性作用。
关键词 aber 反激式开关电源 仿真
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Design and Analysis of Spatial Modulation Based Orthogonal Time Frequency Space System 被引量:3
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作者 Yingchao Yang Zhiquan Bai +4 位作者 Ke Pang Piming Ma Haixia Zhang Xinghai Yang Dongfeng Yuan 《China Communications》 SCIE CSCD 2021年第8期209-223,共15页
In this paper,we design a spatial modulation based orthogonal time frequency space(SMOTFS)system to achieve improved transmission reliability and meet the high transmission rate and highspeed demands of future mobile ... In this paper,we design a spatial modulation based orthogonal time frequency space(SMOTFS)system to achieve improved transmission reliability and meet the high transmission rate and highspeed demands of future mobile communications,which fully utilizes the characteristics of spatial modulation(SM)and orthogonal time frequency space(OTFS)transmission.The detailed system design and signal processing of the SM-OTFS system have been presented.The closed-form expressions of the average symbol error rate(ASER)and average bit error rate(ABER)of the SM-OTFS system have been derived over the delay-Doppler channel with the help of the union bounding technique and moment-generating function(MGF).Meanwhile,the system complexity has been evaluated.Numerical results verify the correctness of the theoretical ASER and ABER analysis of the SM-OTFS system in the high signal-to-noise ratio(SNR)regions and also show that the SM-OTFS system outperforms the traditional SM based orthogonal frequency division multiplexing(SM-OFDM)system with limited complexity increase under mobile conditions,especially in high mobility scenarios. 展开更多
关键词 orthogonal time frequency space(OTFS) spatial modulation based OTFS(SM-OTFS) delay-Doppler domain average symbol error rate(ASER) average bit error rate(ABER)
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AF三跳协作分集中基于最小ABER的最优功率分配算法 被引量:1
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作者 王莉 李韧 张恩展 《广东通信技术》 2008年第1期22-25,29,共5页
协作分集技术融合了中继和分集的思想,使得单天线移动终端也可以利用多输入多输出(MIMO)技术。首先给出了两协作节点参与的三跳协作分集系统的信道模型,介绍了前向放大(AF)协议下的系统工作过程,给出了调制方式为BPSK,接收端采用最大比... 协作分集技术融合了中继和分集的思想,使得单天线移动终端也可以利用多输入多输出(MIMO)技术。首先给出了两协作节点参与的三跳协作分集系统的信道模型,介绍了前向放大(AF)协议下的系统工作过程,给出了调制方式为BPSK,接收端采用最大比合并(MRC)算法下输出平均误码率(ABER)的近似表达式。在此基础上,提出了一种以最小ABER为目标的最优功率分配算法。仿真结果表明,在保持总发射功率不变的前提下,提出的算法较平均功率分配算法能够有效地提高系统的误码率性能。 展开更多
关键词 协作分类 功率分配 平均误码率(ABER) 最大比合并(MRC)
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瑞利信道中的选择合并技术
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作者 朱中华 《桂林电子工业学院学报》 2004年第6期14-17,共4页
分集接收技术在现代移动通信系统中,主要用以对抗由于快衰落引起的接收信号的快速变化,但同时也可以减轻由于阴影效应引起的慢衰落。瑞利信道分集接收的技术是针对在瑞利衰落环境下BPSK信号的ABER(平均误比特率),通过计算机仿真比较了a-... 分集接收技术在现代移动通信系统中,主要用以对抗由于快衰落引起的接收信号的快速变化,但同时也可以减轻由于阴影效应引起的慢衰落。瑞利信道分集接收的技术是针对在瑞利衰落环境下BPSK信号的ABER(平均误比特率),通过计算机仿真比较了a-SDC,r-SDC,aw-SDC,ar-SDC,MRC以及a-GSC等分集技术,可以看出某些选择合并技术在性能和复杂度方面明显优于其他分集技术。 展开更多
关键词 分集 RAKE接收机 瑞利衰落信道 SNR ABER
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A relay selection scheme based on geometric optimum in cooperative cognitive systems over mixed channels
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作者 李静叶 Luo Tao +1 位作者 Shao Yubin Yue Guangxin 《High Technology Letters》 EI CAS 2013年第3期321-326,共6页
This paper proposes a relay selection scheme based on geometric optimum principle to maximize the cognitive link' s connectivity with limited interference to primary user in cooperative cognitive systems. A dual-hop ... This paper proposes a relay selection scheme based on geometric optimum principle to maximize the cognitive link' s connectivity with limited interference to primary user in cooperative cognitive systems. A dual-hop cognitive relay system is considered, in which the channel impulse response follows independent non-identical distribution (i. n. d. ) each hop, such as Rician, Rayleigh and Nakagami-m distribution. Then, closed-form expressions in terms of outage probability and average bit error rate (ABER) are obtained using amplify-and-forward (AF) relaying protocol over such mixed fading channels. Furthermore, the best range of the relay is derived. Extensive simulation re- suits are conducted to verify the theoretical analysis, which is useful to the network optimal design. 展开更多
关键词 cognitive radio (CR) RELAY outage probability average bit error rate (ABER) mixed channels
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Long way up:rethink diseases in light of phase separation and phase transition 被引量:1
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作者 Mingrui Ding Weifan Xu +1 位作者 Gaofeng Pei Pilong Li 《Protein & Cell》 SCIE CSCD 2024年第7期475-492,共18页
Biomolecular condensation, driven by multivalency, serves as a fundamental mechanism within cells, facilitating the formation of distinct compartments, including membraneless organelles that play essential roles in va... Biomolecular condensation, driven by multivalency, serves as a fundamental mechanism within cells, facilitating the formation of distinct compartments, including membraneless organelles that play essential roles in various cellular processes. Perturbations in the delicate equilibrium of condensation, whether resulting in gain or loss of phase separation, have robustly been associated with cellular dysfunction and physiological disorders. As ongoing research endeavors wholeheartedly embrace this newly acknowledged principle, a transformative shift is occurring in our comprehension of disease. Consequently, significant strides have been made in unraveling the profound relevance and potential causal connections between abnormal phase separation and various diseases. This comprehensive review presents compelling recent evidence that highlight the intricate associations between aberrant phase separation and neurodegenerative diseases, cancers, and infectious diseases. Additionally, we provide a succinct summary of current efforts and propose innovative solutions for the development of potential therapeutics to combat the pathological consequences attributed to aberrant phase separation. 展开更多
关键词 MULTIVALENCY COMPARTMENTS aberant phase separation THERAPEUTICS gain or loss of phase separation DISEASES
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应用听觉脑干诱发反应对新生儿轻型缺氧缺血性脑病的观察 被引量:3
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作者 孙洁廉 王虹 +6 位作者 高国琰 周晓薇 赵雅娟 魏保龄 汤浩 章晓芳 张合 《实用儿科杂志》 CSCD 1990年第2期73-74,共2页
新生儿缺氧缺血性脑病(HIE)是围产期常见的疾病,由于医学的进步提高了存活率,但重症往往导致神经系统的后遗症,轻症常被临床所忽视,对其是否发生后遗症,国内尚无报道.我们通过临床观察,应用听觉脑干诱发反应(Auditory brainst(?)m cvoke... 新生儿缺氧缺血性脑病(HIE)是围产期常见的疾病,由于医学的进步提高了存活率,但重症往往导致神经系统的后遗症,轻症常被临床所忽视,对其是否发生后遗症,国内尚无报道.我们通过临床观察,应用听觉脑干诱发反应(Auditory brainst(?)m cvoked re-sponse,ABR,ABER)检查对30名轻型HIE 进行了检测及随访,现报道如下. 展开更多
关键词 缺氧缺血性 ABER 新生儿 脑病
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