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基于波段选择的烟草病害检测模型 被引量:2
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作者 潘兆杰 孙根云 +3 位作者 张爱竹 付航 王新伟 任广伟 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2023年第4期1023-1029,共7页
烟草是我国重要的经济作物,税收的重要来源,为国家的经济发展做出了巨大贡献,然而,烟草病害严重影响烟叶产量与品质。采用光谱分析技术对烟草病害进行早期防治具有非常重要的现实意义。以接种烟草花叶病毒(TMV)与马铃薯Y病毒(PVY)的烟... 烟草是我国重要的经济作物,税收的重要来源,为国家的经济发展做出了巨大贡献,然而,烟草病害严重影响烟叶产量与品质。采用光谱分析技术对烟草病害进行早期防治具有非常重要的现实意义。以接种烟草花叶病毒(TMV)与马铃薯Y病毒(PVY)的烟草为研究对象,分别采集室内与室外培养的染病烟草叶片高光谱数据。为实现对烟草病害的精准识别,每隔两天对两种染病烟草进行光谱数据采集,将每种病害数据详细地分成五个严重度等级,最终获得1697个在350~2500nm波段范围内的光谱数据。为对烟草高光谱数据进行有效利用,以支持向量机(SVM)为基础,结合快速近邻波段选择算法(FNGBS)与归一化匹配滤波(NMFW),提出一种聚类与排序相结合的波段选择算法(FNG-NMFW)。FNG-NMFW首先采用FNGBS算法对烟草光谱进行精细分组,再采用NMFW算法对各组波段进行排序以选择特征光谱,实现烟草光谱特征提取与降维。在波段选择的基础上,采用SVM对烟草特征光谱进行分类,最终实现高精度烟草病害检测。研究结果显示:该模型性能稳定,在样本数量较少情况下,即可实现TMV与PVY两种病害的高精度识别。对于TMV1与TMV3,该算法可以获得精度优于94%的检测结果,对于PVY1与PVY3,该算法精度接近90%,表明该算法可有效完成两种病害早期的识别与预防工作。与采用全波段光谱数据进行病害检测的模型相比,FNG-NMFW模型优势明显,烟草病害检测结果总体精度达94.46%,精度提高约1.5%,检测时间由12.9s缩短为1.1s。 展开更多
关键词 烟草病害 精准识别 高光谱 波段选择 支持向量机
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Effect of lumiracoxib on proliferation and apoptosis of human aonsmall cell lung cancer cells in vitro 被引量:9
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作者 HAO Ji-qing LI Qi +2 位作者 XU Shu-ping SHEN Yu-xian sun gen-yun 《Chinese Medical Journal》 SCIE CAS CSCD 2008年第7期602-607,共6页
Background Lumiracoxib is a highly selective cyclooxygenase-2 (COX-2) inhibitor with antiinflammatory, analgesic and antipyretic activities comparable with class specific drugs, but with much improved gastrointestin... Background Lumiracoxib is a highly selective cyclooxygenase-2 (COX-2) inhibitor with antiinflammatory, analgesic and antipyretic activities comparable with class specific drugs, but with much improved gastrointestinal safety. No studies have examined lumiracoxib for antitumorigenic activity on human nonsmall cell lung cancer cell lines in vitro or its possible molecular mechanisms. Methods The antiproliferative effect of lumiracoxib alone or combined with docetaxol on A549 and NCI-H460 lines was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Drug-drug interactions were analyzed using the coefficient of drug interaction (CDI) to characterize the interactions as synergism, additivity or antagonism. Morphological changes were observed by acridine orange fluorescent staining. Extent of apoptosis was determined by flow cytometry. Results Lumiracoxib (15-240 pmol/L) has an inhibitory effect on the proliferation of A549 and NCI-H460 cell lines in concentration- and time-dependent manners with the ICso values of 2597 pmol/L and 833 pmol/L, respectively. The synergistic effect was prominent when lumiracoxib (15-240 pmoVL) was combined with docetaxol (0.2-2 pmol/L) (CDI 〈1). Fluorescent staining showed that lumiracoxib could induce apoptosis in A549 and NCI-H460 cells. Lumiracoxib treatment also caused an increase of the sub-G1 fraction in each cell line and resulted in an increase of G0/Gl-phase cells and a decrease of S-phase cells. Conclusions Lumiracoxib had antiproliferative effect on the human nonsmall cell lung cancer cell lines A549 and NCI-H460 and had a significant synergy with docetaxol, which may be related to apoptotic induction and cell cycle arrest. 展开更多
关键词 cyclooxygenase-2 inhibitors LUMIRACOXIB docetaxol lung cancer APOPTOSIS cell cycle
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