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Huating Kong Jichao Zhang Jiang Li Jian Wang Hyun-Joon Shin Renzhong Tai Qinglong Yan Kai Xia Jun Hu Lihua Wang Ying Zhu Chunhai Fan 《国家科学评论(英文版)》2020,7(7):1218
Spatial resolution defines the physical limit of microscopes for probing biomolecular localization and interactions in cells. Whereas synchrotron-based X-ray microscopy (XRM) represents a unique approach for imaging a whole cell with nanoscale resolution due to its intrinsic nanoscale resolution and great penetration ability, existing approaches to label biomolecules rely on the use of exogenous tags that are multi-step and error-prone. Here, we repurpose engineered peroxidases as genetically encoded X-ray-sensitive tags (GXET) for site-specific labeling of protein-of-interest in mammalian cells. We find that 3,3′-diaminobenzidine (DAB) polymers that are in-situ catalytically formed by fusion-expressed peroxidases are visible under XRM. Using this new tag, we imaged the protein location associated with the alteration of a DNA-methylation pathway with an ultra-high resolution of 30 nanometers. Importantly, the excellent energy resolution of XRM enables multicolor imaging using different peroxidase tags. The development of GXET enlightens the way to nanoscopic imaging for biological studies. 相似文献
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以乙二胺、三羟甲基丙烷三丙烯酸酯和二乙醇胺或三羟甲基氨基甲烷为原料,合成了水溶性树枝状聚（胺-酯）.讨论了树枝状聚（胺-酯）用量、离心时间及溶液pH值对于Cr3＋去除率的影响.实验结果表明,25℃时,当pH=9.22,以3000 r/min的转速离心13 min,用20 mL PAE（NH2）8（c=0.01 mol/L）溶液处理10 mL CrCl3（c=0.1 mol/L）溶液时,Cr3＋的去除率最高,为81.72%;25℃时,当pH=8.48,以3000 r/min的转速离心10 min,用20 mL PAE（OH）16（c=0.01 mol/L）溶液处理10 mL CrCl3（c=0.1 mol/L）溶液时,Cr3＋的去除率最高,为90.85%;25℃时,当pH=7.67,以3000 r/min的转速离心7 min,用20 mL PAE（OH）24（c=0.01 mol/L）溶液处理10 mL CrCl3（c=0.1 mol/L）溶液时,Cr3＋的去除率最高,为95.17%. 相似文献
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3-Ethyl-5-trifluoromethyl-1,2,4-triazole is synthesized by a one-pot reaction. Using this asymmetric triazole ligand bearing one trifluoromethyl and one ethyl as side groups, we construct two new porous coordination polymers, MAF-9 and MAF-2F, being isostructural with the classic hydrophobic and flexible materials, FMOF-1 and MAF-2, based on symmetric triazole ligands bearing two trifluoromethyl groups or two ethyl groups, respectively. MAF-9 and MAF-2F can adsorb large amounts of organic solvents but completely exclude water, showing superhydrophobicity with water contact angles of 152o in between those of FMOF-1 and MAF-2. MAF-9 exhibits very large N2-induced breathing and colossal positive and negative thermal expansions like FMOF-1, but the lower molecular weight and smaller volume of MAF-9 give 16% and 4% higher gravimetric and volumetric N2 uptakes, respectively. In contrast, MAF-2F is quite rigid and does not show the inversed temperature-dependent N2 adsorption and large guest-induced expansion like MAF-2. Further, despite the higher molecular weight and larger volume, MAF-2F possesses 6% and 25% higher gravimetric and volumetric CO2 uptakes, respectively. These results can be explained by the different pore sizes and side group arrangements in the two classic framework prototypes, which demonstrate the delicate roles of ligand side groups in controlling porosity, surface characteristic and flexibility. 相似文献
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环保型水性上光油的制备及性能 总被引：1，自引：0，他引：1
采用半连续种子乳液聚合的方法,选择合适的单体进行乳液聚合,合成了印刷用环保型上光油,探讨了丙烯酸丁酯和甲基丙烯酸甲酯的比例、乳化剂的种类和用量、引发剂用量及pH值对乳液性能的影响,结果表明：丙烯酸丁酯和甲基丙烯酸甲酯比例为0．85,OP-10与SDS组成的复合乳化剂用量为2．5％,引发荆为0．25％时最佳,该上光油具有光泽好,耐化学品性能强,稳定性良好等特点。 相似文献
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根据线切割机对线切割液的要求,本文对传统线切割工作液存在的问题进行了分析,并拟定了新的研究方法及实验方案,并同时进行了实际应用。 相似文献
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在水热条件下通过混合配体合成了一个3d-4f配位聚合物:[DyCo(2,3-pydc)2 (C2O4)0.5(H2O)3]· 3H2O.通过单晶X-射线衍射仪确定了该配合物的结构信息,进一步利用元素分析、红外光谱、热重对其进行了表征,测定了配合物的磁性质. 相似文献
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以改性壳聚糖分子为基体,采用分子印迹技术合成了对有机磷农药久效磷有选择性的聚合物,并得到了相应的标准曲线。 相似文献
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刘小英 《泉州师范学院学报》2005,23(4):51-54
用非等温热重法研究了腰果酚甲醛铁聚合物的热分解反应动力学,结果表明：腰果酚甲醛铁聚合物的热分解过程是一级反应，用Ozawa法和Reich法求得的平均活化能分别为191．1kJ／mol和191．0kJ／mol。 相似文献
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介绍了几种常见的高分子聚合物的性质及其在医学中的应用。可用于外科手术的缝线、骨科固定和组织修复、药物控释体系中的药物载体材料等。 相似文献