排序方式: 共有43条查询结果,搜索用时 15 毫秒
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目的 基于铜纳米簇(coppernanoclusters,CuNCs)/金属有机框架(metal-organicframeworks,MOF)复合材料谷胱甘肽(glutathione, GSH)-CuNCs/Al-MOF构建一种智能检测小白菜中百草枯的快速、简便的方法。方法 利用化学还原法和溶剂热法制备由GSH修饰的GSH-CuNCs和Al-MOF,合成新型荧光传感材料GSH-CuNCs/Al-MOF,并构建一种比率型荧光检测方法。通过百草枯和GSH-Cu NCs的电子转移和静电相互作用, GSH-CuNCs聚集荧光发生淬灭,而Al-MOF的荧光强度在整个过程中保持不变,复合探针的荧光强度比率反映百草枯的浓度。结果 百草枯在5~100μmol/L范围内线性关系良好,检出限为1.4μmol/L,检测时间为7~15min,选择性和抗干扰能力良好。利用智能手机RGB识别可视化定量检测百草枯,检出限为4.4μmol/L。方法可用于小白菜中百草枯的检测,回收率为96.05%~106.30%。结论 该方法首次实现对百草枯的比率荧光智能检测,具有快速、简便、低成本等特点,为联吡啶类除草剂的检测提供研... 相似文献
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Min Huang Dan Lou Qian Cai Xiuli Chang Xinjin Wang Zhijun Zhou 《International journal of molecular sciences》2014,15(10):18422-18436
Aberration during the development of the central nervous system (CNS) due to environmental factors underlies a variety of adverse developmental outcomes. Paraquat (PQ) is a widely studied neurotoxicant that perturbs the normal structure/function of adult CNS. Yet, the impacts of PQ exposure on the developing CNS remain unclear. miRNAs represent a class of small non-coding RNA molecules involved in the regulation of neural development. Thus in the present study, we analyzed the impacts of PQ on the miRNome of human neural progenitor cells (hNPCs) during proliferation by using the Exiqon miRCURY™ LNA Array. A total of 66 miRNAs were identified as differentially expressed in proliferating hNPCs upon PQ treatment. miRTarBase prediction identified 1465 mRNAs, including several genes (e.g., nestin, sox1, ngn1) previously proved to be associated with the neural proliferation and differentiation, as target genes of PQ-induced differentially expressed miRNAs. The database for annotation, visualization and integrated discovery (DAVID) bioinformatics analysis showed that target genes were enriched in regulation of cell proliferation and differentiation, cell cycle and apoptosis as well as tumor protein 53 (p53), Wnt, Notch and mitogen-activated protein kinases (MAPK) signaling pathways (p < 0.001). These findings were confirmed by real-time RT-PCR. Based on our results we conclude that PQ-induced impacts on the miRNA profiling of hNPCs undergoing proliferation may underlie the developmental neurotoxicity of PQ. 相似文献
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MMA经溴化加成、醚化、催化裂化制得双甲醋;单氰胺与二硫化碳在碱性条件下缩合、甲基化制备二氰醋,后与正丙胺缩合再与水合肼环合,丙三唑与苯甲醛醛缩;醛缩物在缚酸剂下与双甲醋催化闭环生成环合物。再在盐酸中水解去醛基得三唑嘧啶酮成品。分别选择car1#、cat2#为裂解和闭环催化剂,反应收率分别达91.59%,91.98%,91.1%,86.6%,69.7%,总收率46.32%,产品纯度99.53%。 相似文献
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目的建立超高效液相色谱-串联质谱法快速测定6种蔬菜和水果以及玉米、香菇等其他植物源性样品中百草枯和敌草快的分析方法。方法样品先以0.5 mol/L HCl浸泡酸化5 min,再以10 mL甲醇-0.5 mol/L HCl(1:1, V:V)振荡提取10 min,然后于80℃水浴中保温30 min,提取液冷却后于5000 r/min离心5 min,取上层清液过0.22μm的滤膜,直接上机测定。以20mmol/L甲酸铵(pH=3)-乙腈为流动相,经亲水色谱柱(hydrophilic interaction liquid chromatography, HILIC)进行分离后进行超高效液相色谱-三重四极杆串联质谱多反应监测模式分析,内标法定量。结果百草枯的检出限(limitsofdetection,LOD)、定量限(limitsof quantitation, LOQ)分别为2.0、7.0μg/kg,敌草快的LOD、LOQ分别为1.5、8.0μg/kg。考察了8种不同样品的基质效应,其中敌草快在上海青和西芹中的基质效应较强,需要以基质标准曲线进行定量校正。在10、50、100μg/kg3个浓度水平的加标回收试验下测得,百草枯的回收率为74.6%~120.2%,相对标准偏差(relative standard deviation, RSD)为0.9%~11.7%;敌草快的回收率为76.6%~124.9%, RSD为2.0%~12.1%。结论该方法操作简单,快速。以内标法和基质匹配曲线定量,结果准确,适用于大量蔬菜水果样品中百草枯和敌草快的高通量分析和检测。 相似文献
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[目的]目前百草枯水剂中臭味剂的分析方法尚未见报道,随着百草枯水剂日益广泛的使用和愈发严格的市场监管,急需建立一个合适的分析方法.[方法]在碱性条件下,以甲苯为萃取剂萃取百草枯水剂中的臭味剂烷基吡啶.采用FID,HP-Innowax毛细管色谱柱,1,3,5-三甲苯为内标物,建立了气相色谱分析法.对萃取物中的3,5-二甲基吡啶、2,3-二甲基吡啶和3-乙基吡啶进行定量分析.[结果]方法的回收率在98%左右,标准偏差分别为0.0029、0.0020、0.0007,变异系数分别为0.0042%、0.0081%、0.0101%,线性相关系数均为1.[结论]该方法适用于百草枯水剂中烷基吡啶臭味剂的定量分析. 相似文献
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A comparison of the in vitro permeability properties of human and some laboratory animal skins 总被引:1,自引:0,他引:1
The in vitro permeability of human and some common laboratory animals'skin has been measured to two chemicals with different physico-chemical properties: [3 H] water, a small polar molecule and [14 C]paraquat dichloride (the ion), a fully ionised divalent cation. All the skins examined had similar permeabilities to [3 H]water: relative to human skin the greatest difference (x4.8) was measured through guinea pig skin. However, relative to human skin, all the animals were much more permeable to [14 C]paraquat, with factors of difference ranging between 40 (haired rat) and 1460 (hairless mouse). The in vitro technique allows the permeability of human and animal skin to be compared, facilitating extrapolation to Man of effects seen in animals during dermal exposure studies.
Comparaison de la permeabilite in vitro de la peau humaine et de la peau de certains animaux de laboratoire 相似文献
Comparaison de la permeabilite in vitro de la peau humaine et de la peau de certains animaux de laboratoire 相似文献
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目的建立高效液相色谱-串联质谱法快速检测食物中毒事件中常见样品(如食品、血液及尿液等)中百草枯和敌草快的分析方法。方法分别以乙酸乙酯为溶剂提取食品和尿液样品、以乙腈为溶剂提取血液样品中的百草枯和敌草快,提取液氮吹浓缩至近干,加入流动相复溶,再经0.22μm滤膜过滤。采用WATERS ACQUITY UPLC BEH Amide色谱柱分离,以乙腈(A)-100 mmol/L甲酸铵溶液(含0.05%甲酸)(B)(60:40,V:V)为流动相等度洗脱,多反应模式监测,外标法定量。结果百草枯和敌草快在2.0~100μg/L质量浓度范围内线性关系良好,相关系数为0.9971~0.9999。百草枯和敌草快的检出限(S/N=3)分别为1.0μg/L和0.3μg/L,定量限(S/N=10)分别为3.0μg/L和1.0μg/L。加标水平为2.0、10.0、80.0μg/L时,百草枯和敌草快回收率分别为82.4%~98.4%和90.1%~103.5%,相对标准偏差分别为0.8%~5.1%和1.0%~4.2%。结论本方法建立的分析过程样品前处理简单、快速、准确,适用于食品、血液和尿液中的百草枯和敌草快的同时测定。 相似文献