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基于线粒体D-loop区和COI基因序列研究2个禾花鲤群体和野生鲤群体的遗传多样性与系统进化关系 被引量:15
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作者 潘贤辉 周康奇 +9 位作者 陈忠 杜雪松 黄姻 覃俊奇 文露婷 潘志忠 邓潜 罗辉 叶华 林勇 《淡水渔业》 CSCD 北大核心 2019年第6期33-40,共8页
利用线粒体D-loop区和COI基因序列分析了全州禾花鲤(Quanzhou Procypris merus)、融水禾花鲤(Rongshui P.merus)和野生鲤鱼群体的遗传多样性和系统进化关系。基于D-loop区序列分析结果表明:序列长度为927~930 bp,共统计变异位点53个;A、... 利用线粒体D-loop区和COI基因序列分析了全州禾花鲤(Quanzhou Procypris merus)、融水禾花鲤(Rongshui P.merus)和野生鲤鱼群体的遗传多样性和系统进化关系。基于D-loop区序列分析结果表明:序列长度为927~930 bp,共统计变异位点53个;A、T、G、C核苷酸平均含量分别为33.4%、32.9%、14%和19.7%,A+T(66.3%)明显高于G+C(33.7%);总体的单倍型数(h)、单倍型多样性(Hd)和核苷酸多样性(π)分别为40个、0.95和0.0083;遗传分化指数(Fst)为0.22459。基于COI基因序列分析结果显示:序列长度为897~899 bp,共统计变异位点33个;A、T、G、C核苷酸平均含量分别为26.7%、28.5%、17.8%和27%,且A+T(55.2%)高于G+C(44.8%);总体的h为25个,Hd为0.91,π为0.00316;Fst值为0.19143。在3个群体内和群体间遗传距离分别在0.003~0.009和0.003~0.01,远小于种群分类水平0.05。分子方差分析(AMOVA)结果表明,77.54%(D-loop)和80.86%(COI)变异来自群体间变异,22.46%(D-loop)和19.14%(COI)来自群体内变异。单倍型进化树和网络图显示,全州禾花鲤和野鲤群体均存在单独聚为一支的单倍型,而融水群体未出现单独成支现象。研究表明,线粒体D-loop区作为反映3个群体间遗传多样性的灵敏度要高于COI基因,并且3个群体均属于高单倍型多样性和高核苷酸多样性。综上,3个群体间出现了较为明显的分化现象。 展开更多
关键词 线粒体DNA 禾花鲤(Procypris merus) 遗传多样性 系统进化
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高导热金属基复合材料的制备与研究进展 被引量:7
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作者 陈贞睿 刘超 +3 位作者 谢炎崇 潘志忠 任淑彬 曲选辉 《粉末冶金技术》 CAS CSCD 北大核心 2022年第1期40-52,共13页
随着电子器件芯片功率的不断提高,对散热材料的热物理性能提出了更高的要求。将高导热、低膨胀的增强相和高导热的金属进行复合得到的金属基复合材料,能够兼顾高的热导率和可调控的热膨胀系数,是理想的散热材料。本文对以Si、SiC_(p)、... 随着电子器件芯片功率的不断提高,对散热材料的热物理性能提出了更高的要求。将高导热、低膨胀的增强相和高导热的金属进行复合得到的金属基复合材料,能够兼顾高的热导率和可调控的热膨胀系数,是理想的散热材料。本文对以Si、SiC_(p)、金刚石、鳞片石墨为增强相的铜基及铝基复合材料的研究进展进行了总结,并就金属基复合材料目前存在的问题及未来的研究方向进行了展望。 展开更多
关键词 金属基复合材料 热导率 物理性能 研究进展
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A multivariate analysis of prognostic determinants for stages Ⅱ and Ⅲ colorectal cancer in 141 patients 被引量:1
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作者 ZHOU Zhong-guo WU Xiao-jun +4 位作者 LI Li-ren PENG Zhi-heng DING Pei-rong WANG Ruo-jing pan zhi-zhong 《Chinese Medical Journal》 SCIE CAS CSCD 2011年第14期2132-2135,共4页
Background Previous prognosis analyses of colorectal cancer (CRC) patients with stage Ⅱ and Ⅲ disease were done as separate categories. The purpose of this study was to analyze prognostic factors associated with s... Background Previous prognosis analyses of colorectal cancer (CRC) patients with stage Ⅱ and Ⅲ disease were done as separate categories. The purpose of this study was to analyze prognostic factors associated with survival in a group of patients who underwent radical resection of stages Ⅱ and Ⅲ CRC.Methods A retrospective review was performed for 141 consecutive stages Ⅱ and Ⅲ patients who had undergone radical resection of coloractal adenocarcinoma between May 2003 and November 2003. Univariate and multivariate analyses were performed to assess the effect of record variables on disease free survival and overall survival.Results The median follow-up time was 59 months, and the 3-and 5-year survival rates were 76% and 68%,respectively. Four factors were independently associated with a worse disease-free survival: diabetes (hazard ratio (HR) 2.338; 95% confidence interval (CI) 1.011-5.407), expression of cyclooxygenase-2 (Cox-2) (HR 0.335; 95% CI 0.126-0.888), expression of matrix metalloproteinases 2 (MMP-2) (FIR 0.233; 95% CI 0.101-0.541), expression of vascular endothelial growth factor (VEGF) (HR 0.295; 95% CI 0.088-0.996). Four factors were independently associated with a worse overall survival: lymph nodes metastasis (HR 1.67; 95% CI 1.29-2.14), Cox-2 positive (HR 0.056; 95% CI 0.247-0.731), MMP-2 positive (HR 0.398; 95% CI 0.190-0.836), VEGF (HR 0.364; 95% CI 0.090-0.716).Conclusions Diabetes, expression of Cox-2, MMP-2 and VEGF were independently associated with a worse diseasefree survival. Lymph nodes metastasis, expression of Cox-2, MMP-2 and high level of VEGF predicted a poor overall survival. 展开更多
关键词 colorectal cancer stage stage PROGNOSIS
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