Methanol-to-hydrocarbons(MTH)reaction comprises a set of crucial catalytic processes to produce light olefins,gasoline,or aromatics.MTH reaction is a classic example of reaction complexity in zeolite catalysis.The mol...Methanol-to-hydrocarbons(MTH)reaction comprises a set of crucial catalytic processes to produce light olefins,gasoline,or aromatics.MTH reaction is a classic example of reaction complexity in zeolite catalysis.The molecular understanding of reaction routes and deactivation mechanisms still encounters many challenges.Herein,we chose HZSM-22 zeolite with the simple one-dimensional 10-membered ring(10-MR)channel as a prototypical system,leveraging the spatial nanoconfinement effect of its unique pore architecture to minimize reaction complexity.The identification of the molecular structures of coke species with acene-,biphenyl-,or fluorene-typed structures was made possible through a combination of the advanced matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry(MALDI FT-ICR MS)with the gas chromatography-mass spectrometer(GC-MS)technique.With this,we uncovered two modes of growth mechanism of coke molecules,i.e.,a stepwise route and a dehydrogenative coupling route.The findings deepen the mechanistic understanding of zeolite deactivation and provide a theoretical foundation for designing coke-resistant catalysts.展开更多
MTH1(mut T homolog1)是Mut T的同源酶,是一种核苷酸焦磷酸酶,主要参与DNA损伤修复过程,尤其在肿瘤细胞的DNA复制过程中发挥着重要角色。最新的研究表明,MTH1可以清除肿瘤细胞中受损DNA功能结构的氧化构件,使得肿瘤细胞继续分裂与增殖,...MTH1(mut T homolog1)是Mut T的同源酶,是一种核苷酸焦磷酸酶,主要参与DNA损伤修复过程,尤其在肿瘤细胞的DNA复制过程中发挥着重要角色。最新的研究表明,MTH1可以清除肿瘤细胞中受损DNA功能结构的氧化构件,使得肿瘤细胞继续分裂与增殖,从而维持肿瘤细胞的生存,而更为重要的是正常细胞不需要MTH1,因此,MTH1有可能只与异常的细胞生长密切相关,这使得MTH1作为治疗靶点成为人们关注的焦点。该文着重对MTH1与肿瘤关系最新的研究成果进行综述,探讨MTH1维持肿瘤生长的相关机制及其与肿瘤治疗的关系,为靶向MTH1治疗肿瘤提供新的思路,为肿瘤研究工作者提供重要参考。展开更多
目的建立敲减MTH1基因的HeLa细胞稳定细胞株,研究MTH1基因的低表达对HeLa细胞内RNA氧化程度的影响。方法设计并合成针对MTH1基因的3条siRNA,分别转染HeLa细胞,选择干扰效果最为理想的靶序列连接入反转录病毒载体Retro-Q,在293T细胞内包...目的建立敲减MTH1基因的HeLa细胞稳定细胞株,研究MTH1基因的低表达对HeLa细胞内RNA氧化程度的影响。方法设计并合成针对MTH1基因的3条siRNA,分别转染HeLa细胞,选择干扰效果最为理想的靶序列连接入反转录病毒载体Retro-Q,在293T细胞内包装病毒颗粒,将病毒转染HeLa细胞后使用嘌呤霉素筛选抗性克隆株,用western b lot技术检测克隆株的MTH1的表达量以确定干扰效果最理想的稳定细胞株,用API5000型质谱仪检测稳定细胞株RNA中的8-oxoG与G的含量以评价RNA的氧化程度。结果本研究设计的3条siRNA中有2条干扰效率可达90%以上,所建立的敲减MTH1基因HeLa细胞稳定细胞株的干扰效果达80%以上,质谱检测结果表明MTH1基因低表达的稳定细胞株每106个G中含有14.9个8-oxoG,而对照细胞中则仅含9.7个8-oxoG。结论 MTH1基因的低表达可引起HeLa细胞中RNA氧化程度明显升高。展开更多
基金financially supported by the National Key R&D Program of China(2024YFB4105401)the National Natural Science Foundation of China(22372164,22288101 and 22072148)。
文摘Methanol-to-hydrocarbons(MTH)reaction comprises a set of crucial catalytic processes to produce light olefins,gasoline,or aromatics.MTH reaction is a classic example of reaction complexity in zeolite catalysis.The molecular understanding of reaction routes and deactivation mechanisms still encounters many challenges.Herein,we chose HZSM-22 zeolite with the simple one-dimensional 10-membered ring(10-MR)channel as a prototypical system,leveraging the spatial nanoconfinement effect of its unique pore architecture to minimize reaction complexity.The identification of the molecular structures of coke species with acene-,biphenyl-,or fluorene-typed structures was made possible through a combination of the advanced matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry(MALDI FT-ICR MS)with the gas chromatography-mass spectrometer(GC-MS)technique.With this,we uncovered two modes of growth mechanism of coke molecules,i.e.,a stepwise route and a dehydrogenative coupling route.The findings deepen the mechanistic understanding of zeolite deactivation and provide a theoretical foundation for designing coke-resistant catalysts.
文摘MTH1(mut T homolog1)是Mut T的同源酶,是一种核苷酸焦磷酸酶,主要参与DNA损伤修复过程,尤其在肿瘤细胞的DNA复制过程中发挥着重要角色。最新的研究表明,MTH1可以清除肿瘤细胞中受损DNA功能结构的氧化构件,使得肿瘤细胞继续分裂与增殖,从而维持肿瘤细胞的生存,而更为重要的是正常细胞不需要MTH1,因此,MTH1有可能只与异常的细胞生长密切相关,这使得MTH1作为治疗靶点成为人们关注的焦点。该文着重对MTH1与肿瘤关系最新的研究成果进行综述,探讨MTH1维持肿瘤生长的相关机制及其与肿瘤治疗的关系,为靶向MTH1治疗肿瘤提供新的思路,为肿瘤研究工作者提供重要参考。
文摘目的建立敲减MTH1基因的HeLa细胞稳定细胞株,研究MTH1基因的低表达对HeLa细胞内RNA氧化程度的影响。方法设计并合成针对MTH1基因的3条siRNA,分别转染HeLa细胞,选择干扰效果最为理想的靶序列连接入反转录病毒载体Retro-Q,在293T细胞内包装病毒颗粒,将病毒转染HeLa细胞后使用嘌呤霉素筛选抗性克隆株,用western b lot技术检测克隆株的MTH1的表达量以确定干扰效果最理想的稳定细胞株,用API5000型质谱仪检测稳定细胞株RNA中的8-oxoG与G的含量以评价RNA的氧化程度。结果本研究设计的3条siRNA中有2条干扰效率可达90%以上,所建立的敲减MTH1基因HeLa细胞稳定细胞株的干扰效果达80%以上,质谱检测结果表明MTH1基因低表达的稳定细胞株每106个G中含有14.9个8-oxoG,而对照细胞中则仅含9.7个8-oxoG。结论 MTH1基因的低表达可引起HeLa细胞中RNA氧化程度明显升高。
