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优化初始聚类中心的改进K-means算法 被引量:33
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作者 唐东凯 王红梅 +1 位作者 胡明 刘钢 《小型微型计算机系统》 CSCD 北大核心 2018年第8期1819-1823,共5页
针对K-means算法对初始聚类中心和离群点敏感的缺点,提出了一种优化初始聚类中心的改进K-means算法.该算法首先计算出数据集中每个数据对象的离群因子,并根据离群因子的值对数据集进行升序排列,使得中心点的位置靠前.然后在升序排列的... 针对K-means算法对初始聚类中心和离群点敏感的缺点,提出了一种优化初始聚类中心的改进K-means算法.该算法首先计算出数据集中每个数据对象的离群因子,并根据离群因子的值对数据集进行升序排列,使得中心点的位置靠前.然后在升序排列的数据集上,引入取样因子α,得到候选初始中心点集.最后,根据最大最小距离的思想,在候选初始中心点集上选取k个数据对象作为初始聚类中心.实验结果表明,在时间基本相同的情况下,提出的改进算法相对K-means、K-means++算法具有较好的稳定性和较高的聚类准确率,并且聚类的平均迭代次数也相对较小. 展开更多
关键词 K-MEANS算法 初始聚类中心 离群因子 取样因子 最大最小距离
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Protective Effect of Silibinin on Lipopolysaccharide-Induced Endotoxemia by Inhibiting Caspase-11-Dependent Cell Pyroptosis
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作者 OU Jin-ying LIU Shan-hong +9 位作者 tang dong-kai SHI Ling-zhu YAN Li-jun HUANG Jing-yan ZOU Li-fang QUAN Jing-yu YOU Yan-ting CHEN Yu-yao YU Lin-zhong LU Zi-bin 《Chinese Journal of Integrative Medicine》 SCIE CAS CSCD 2024年第10期917-926,共10页
Objective:To explore the protective effect and the underlying mechanism of silibinin(SIB),one of the active compounds from Silybum marianum(L.)Gaertn in endotoxemia.Methods:Mouse peritoneal macrophage were isolated vi... Objective:To explore the protective effect and the underlying mechanism of silibinin(SIB),one of the active compounds from Silybum marianum(L.)Gaertn in endotoxemia.Methods:Mouse peritoneal macrophage were isolated via intraperitoneally injection of BALB/c mice with thioglycolate medium.Cell viability was assessed using the cell counting kit-8,while cytotoxicity was determined through lactate dehydrogenase cytotoxicity assay.The protein expressions of interleukin(IL)-1α,IL-1β,and IL-18 were determined by enzyme-linked immunosorbent assay.Intracellular lipopolysaccharide(LPS)levels were measured by employing both the limulus amoebocyte lysate assay and flow cytometry.Additionally,proximity ligation assay was employed for the LPS and caspase-11 interaction.Mice were divided into 4 groups:the control,LPS,high-dose-SIB(100 mg/kg),and low-dose-SIB(100 mg/kg)groups(n=8).Zebrafish were divided into 4 groups:the control,LPS,high-dose-SIB(200μmol/L),and low-dose-SIB(100μmol/L)groups(n=30 for survival experiment and n=10 for gene expression analysis).The expression of caspase-11,gasdermin D(GSDMD),and N-GSDMD was determined by Western blot and the expressions of caspy2,gsdmeb,and IL-1βwere detected using quantitative real-time PCR.Histopathological observation was performed through hematoxylineosin staining,and protein levels in bronchoalveolar lavage fluid were quantified using the bicinchoninicacid protein assay.Results:SIB noticeably decreased caspase-11 and GSDMD-mediated pyroptosis and suppressed the secretion of IL-1α,IL-1β,and IL-18 induced by LPS(P<0.05).Moreover,SIB inhibited the translocation of LPS into the cytoplasm and the binding of caspase-11 and intracellular LPS(P<0.05).SIB also attenuated the expression of caspase-11 and N-terminal fragments of GSDMD,inhibited the relative cytokines,prolonged the survival time,and up-regulated the survival rate in the endotoxemia models(P<0.05).Conclusions:SIB can inhibit pyroptosis in the LPS-mediated endotoxemia model,at least in part,by inhibiting the caspase-11-mediated cleavage of GSDMD.Additionally,SIB inhibits the interaction of LPS and caspase-11 and inhibits the LPS-mediated up-regulation of caspase-11 expression,which relieves caspase-11-dependent cell pyroptosis and consequently attenuates LPS-mediated lethality. 展开更多
关键词 SILIBININ caspase-11 ENDOTOXEMIA PYROPTOSIS inflammation
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