为了评估乌鳢中四环素类药物的残留风险,建立了乌鳢肌肉中4种四环素类药物残留的快速、简单、廉价、高效、耐用和安全的前处理方法(Quick、Easy、Cheap、Effective、Rugged、Safe,QuEChER)。采用Box–Behnken design(BBD)响应面优化法,...为了评估乌鳢中四环素类药物的残留风险,建立了乌鳢肌肉中4种四环素类药物残留的快速、简单、廉价、高效、耐用和安全的前处理方法(Quick、Easy、Cheap、Effective、Rugged、Safe,QuEChER)。采用Box–Behnken design(BBD)响应面优化法,优化了提取和净化条件。样品经10 mL 1%甲酸酸化乙腈和2 mL 0.1 mol/L Na2EDTA-McIlvaine缓冲溶液提取,以150 mg PSA和200 mg C18进行净化,采用超高效液相色谱-串联质谱法(Ultra-high performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)检测。结果表明,该方法在0.50~100 ng/mL浓度范围内线性良好(r≥0.999),检出限(Limit of Detection,LOD)和定量限(Limit of Quantitation,LOQ)分别为0.25~0.75μg/kg和0.84~2.00μg/kg。在乌鳢肌肉中四环素、土霉素、金霉素和多西环素的平均回收率在89.5%~1187%之间,相对标准偏差(RSD)在1.11%~8.88%之间。该方法简便、灵敏、准确,可用于乌鳢中四环素含量的快速测定。展开更多
[Objectives] To explore the inhibitory effect of octadecadienoic acid (ODA) on proliferation and apoptosis of glioma cells and its mechanism. [Methods] Cultured human glioma cells (cell density 2×10^(6) cells/L) ...[Objectives] To explore the inhibitory effect of octadecadienoic acid (ODA) on proliferation and apoptosis of glioma cells and its mechanism. [Methods] Cultured human glioma cells (cell density 2×10^(6) cells/L) were divided into three groups: solvent control group (DMSO, 30 μL/L), 5-FU group (10 mg/L) and octadecadienoic acid group (0.3, 0.6, 1.2 mg/L). The toxic effects of ODA on glioma cells were detected by trypan blue and thiazolium blue (MTT). The expression of P53, PI3K, P21, PKB/Akt and caspase-9 protein in glioma cells were detected by enzyme-linked immunosorbent assay (ELISA). [Results] The cell count under optical microscope showed that the inhibition rate of cell proliferation in low, medium and high dose ODA groups and 5-FU group was significantly higher than that in solvent control group ( P <0.01), but there was no significant difference compared with 5-FU group ( P >0.05). The results of MTT showed that compared with the solvent control group, the inhibition rate of cell proliferation in low, medium and high dose ODA groups and 5-FU group significantly increased ( P <0.01);compared with 5-FU group, the inhibition rate of cell proliferation in high dose ODA group significantly increased ( P <0.01). The results of flow cytometry showed that compared with the solvent control group, the number of cells in G_(0)/G_(1) phase increased significantly ( P <0.05, P <0.01), the number of cells in G_(2)/M phase decreased significantly ( P <0.01) and the apoptosis rate increased significantly ( P <0.01) in the low, medium and high dose ODA groups and 5-FU group;compared with 5-FU group, the number of cells in G_(2)/M phase decreased significantly ( P <0.01) and the apoptosis rate increased significantly ( P <0.01) in ODA group. ELISA testing results showed that the expression levels of P53, P13K and PKB/Akt in low, medium and high dose ODA groups and 5-FU group were significantly lower than those in solvent control group ( P <0.01), and only the expression level of protein in high dose ODA group was significantly lower than that in 5-FU group ( P <0.01);the expression levels of P21 and caspase-9 in low, medium and high dose ODA groups and 5-FU group were significantly higher than those in solvent control group ( P <0.05, P <0.01), but the expression level of protein in high dose ODA group was significantly higher than that in 5-FU group ( P <0.01). [Conclusions] ODA can obviously inhibit the proliferation of glioma cells and induce apoptosis. The mechanism is related to up-regulation of P21, caspase-9, down-regulation of P53, PI3K, PKB/Akt, inhibition of cell division cycle and decrease of PI3K-Akt signal transduction pathway.展开更多
通过两步水热/溶剂热法制备镍钴双金属硫化物电极,首先通过水热反应合成了碳布支撑钴镍前驱体,然后利用无机硫源将S元素掺入前驱体材料中,最终得到了生长在碳布表面的镍钴双金属硫化物材料。控制Co、Ni原料的摩尔比,调控产物的形貌,研...通过两步水热/溶剂热法制备镍钴双金属硫化物电极,首先通过水热反应合成了碳布支撑钴镍前驱体,然后利用无机硫源将S元素掺入前驱体材料中,最终得到了生长在碳布表面的镍钴双金属硫化物材料。控制Co、Ni原料的摩尔比,调控产物的形貌,研究了材料的结构与组成。经过SEM等表征,结果表明:金属源含量影响了产物的形貌,导致材料的电化学性能也存在差异。当金属源摩尔比Co∶Ni=2∶1时,在3 M KOH电解液中,电流密度为1 mA/cm^(2)时,NiCo_(2)S_(4)/CC电极的面积比电容为4789.0 mF/cm^(2)。展开更多
针对滚动轴承故障振动信号的复杂特性和局部均值分解(Local Mean Decomposition,LMD)方法存在的端点效应问题,提出了基于振动信号自相似性对左右端点两侧延拓来抑制端点效应问题的改进LMD、排列熵(Permutation Entropy,PE)及优化K-均值...针对滚动轴承故障振动信号的复杂特性和局部均值分解(Local Mean Decomposition,LMD)方法存在的端点效应问题,提出了基于振动信号自相似性对左右端点两侧延拓来抑制端点效应问题的改进LMD、排列熵(Permutation Entropy,PE)及优化K-均值聚类算法相结合的轴承故障诊断方法。首先通过改进LMD将非线性、非平稳的原始故障振动信号分解出一系列的乘积函数(Production Function,PF)分量,对包含主要故障信息的PF分量提取PE值作为故障特征分量,在提取特征量的基础上,最后采用优化后的K-均值聚类算法对故障类型进行识别分类。将该方法应用在滚动轴承实验数据,实验结果表明该方法可以准确、有效的实现滚动轴承的故障诊断。展开更多
文摘为了评估乌鳢中四环素类药物的残留风险,建立了乌鳢肌肉中4种四环素类药物残留的快速、简单、廉价、高效、耐用和安全的前处理方法(Quick、Easy、Cheap、Effective、Rugged、Safe,QuEChER)。采用Box–Behnken design(BBD)响应面优化法,优化了提取和净化条件。样品经10 mL 1%甲酸酸化乙腈和2 mL 0.1 mol/L Na2EDTA-McIlvaine缓冲溶液提取,以150 mg PSA和200 mg C18进行净化,采用超高效液相色谱-串联质谱法(Ultra-high performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)检测。结果表明,该方法在0.50~100 ng/mL浓度范围内线性良好(r≥0.999),检出限(Limit of Detection,LOD)和定量限(Limit of Quantitation,LOQ)分别为0.25~0.75μg/kg和0.84~2.00μg/kg。在乌鳢肌肉中四环素、土霉素、金霉素和多西环素的平均回收率在89.5%~1187%之间,相对标准偏差(RSD)在1.11%~8.88%之间。该方法简便、灵敏、准确,可用于乌鳢中四环素含量的快速测定。
基金Supported by Gansu Natural Science Foundation(21JR7RA571)Lanzhou Science and Technology Plan Project(2019-1-48)Major Project of Gansu University of Political Science and Law(GZF2021XZD06).
文摘[Objectives] To explore the inhibitory effect of octadecadienoic acid (ODA) on proliferation and apoptosis of glioma cells and its mechanism. [Methods] Cultured human glioma cells (cell density 2×10^(6) cells/L) were divided into three groups: solvent control group (DMSO, 30 μL/L), 5-FU group (10 mg/L) and octadecadienoic acid group (0.3, 0.6, 1.2 mg/L). The toxic effects of ODA on glioma cells were detected by trypan blue and thiazolium blue (MTT). The expression of P53, PI3K, P21, PKB/Akt and caspase-9 protein in glioma cells were detected by enzyme-linked immunosorbent assay (ELISA). [Results] The cell count under optical microscope showed that the inhibition rate of cell proliferation in low, medium and high dose ODA groups and 5-FU group was significantly higher than that in solvent control group ( P <0.01), but there was no significant difference compared with 5-FU group ( P >0.05). The results of MTT showed that compared with the solvent control group, the inhibition rate of cell proliferation in low, medium and high dose ODA groups and 5-FU group significantly increased ( P <0.01);compared with 5-FU group, the inhibition rate of cell proliferation in high dose ODA group significantly increased ( P <0.01). The results of flow cytometry showed that compared with the solvent control group, the number of cells in G_(0)/G_(1) phase increased significantly ( P <0.05, P <0.01), the number of cells in G_(2)/M phase decreased significantly ( P <0.01) and the apoptosis rate increased significantly ( P <0.01) in the low, medium and high dose ODA groups and 5-FU group;compared with 5-FU group, the number of cells in G_(2)/M phase decreased significantly ( P <0.01) and the apoptosis rate increased significantly ( P <0.01) in ODA group. ELISA testing results showed that the expression levels of P53, P13K and PKB/Akt in low, medium and high dose ODA groups and 5-FU group were significantly lower than those in solvent control group ( P <0.01), and only the expression level of protein in high dose ODA group was significantly lower than that in 5-FU group ( P <0.01);the expression levels of P21 and caspase-9 in low, medium and high dose ODA groups and 5-FU group were significantly higher than those in solvent control group ( P <0.05, P <0.01), but the expression level of protein in high dose ODA group was significantly higher than that in 5-FU group ( P <0.01). [Conclusions] ODA can obviously inhibit the proliferation of glioma cells and induce apoptosis. The mechanism is related to up-regulation of P21, caspase-9, down-regulation of P53, PI3K, PKB/Akt, inhibition of cell division cycle and decrease of PI3K-Akt signal transduction pathway.
文摘通过两步水热/溶剂热法制备镍钴双金属硫化物电极,首先通过水热反应合成了碳布支撑钴镍前驱体,然后利用无机硫源将S元素掺入前驱体材料中,最终得到了生长在碳布表面的镍钴双金属硫化物材料。控制Co、Ni原料的摩尔比,调控产物的形貌,研究了材料的结构与组成。经过SEM等表征,结果表明:金属源含量影响了产物的形貌,导致材料的电化学性能也存在差异。当金属源摩尔比Co∶Ni=2∶1时,在3 M KOH电解液中,电流密度为1 mA/cm^(2)时,NiCo_(2)S_(4)/CC电极的面积比电容为4789.0 mF/cm^(2)。
文摘针对滚动轴承故障振动信号的复杂特性和局部均值分解(Local Mean Decomposition,LMD)方法存在的端点效应问题,提出了基于振动信号自相似性对左右端点两侧延拓来抑制端点效应问题的改进LMD、排列熵(Permutation Entropy,PE)及优化K-均值聚类算法相结合的轴承故障诊断方法。首先通过改进LMD将非线性、非平稳的原始故障振动信号分解出一系列的乘积函数(Production Function,PF)分量,对包含主要故障信息的PF分量提取PE值作为故障特征分量,在提取特征量的基础上,最后采用优化后的K-均值聚类算法对故障类型进行识别分类。将该方法应用在滚动轴承实验数据,实验结果表明该方法可以准确、有效的实现滚动轴承的故障诊断。
