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Jinagxi Provincial Department of Education's Item of higher education and teaching reform[JXJG-17-9-14]
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人体邻苯二甲酸酯暴露的尿液生物标志物分析方法
No full text邻苯二甲酸酯(phthalates,PAEs)是一类典型的环境内分泌干扰物。近年来,由于PAEs产量和使用量的增加,其对人体健康的危害尤其是生殖发育毒性受到了人们高度关注。由于PAEs在环境、食物(材)中广泛存在,导致人体不可避免地长期暴露于PAEs化合物,因此很有必要开展人体PAEs暴露评估。对人体尿液样品中的PAEs代谢物进行筛选和定量是评价PAEs暴露的重要手段,而建立它们准确、可靠的分析方法是重要前提。目前,邻苯二甲酸单酯和次级代谢物分别是短链和长链PAEs暴露最为常用的生物标志物。离线或在线固相萃取与高效液相色谱-串联质谱联用已成为测定PAEs代谢物的首选方法。本文主要综述了人体PAEs暴露的尿液生物标志物的分析方法,并讨论了这些方法在实际应用中的优点、局限性及挑战
purificationoftheatgrp7rrmdomainfromarabidopsisthalianaanditspreliminarystructureandbindinganalysis
No full textThe glycine-rich RNA-binding protein, AtGrp7, is a component of a negative feedback loop in the circadian clock regulation of Arabidopsis thaliana. In our initial purification trial of the tobacco etch virus (TEV)-cleaved AtGrp7 RNA recognition motif (RRM) domain with the regular protocol, mixed ultraviolet signals of the target proteins and contaminants were observed. A two-step denaturing-refolding protocol was then tested, trying to solve the problem of impurities. The structure of the AtGrp71-90 RRM domain was fully recovered by quick-dilution refolding, evidenced by the fingerprint 1H-15N HSQC spectrum and CS-Rosetta model structures. Isothermal titration calorimetry (ITC) and NMR titration experiments further confirmed that the RRM domain of AtGrp71-90 had proper functions with regards to RNA/DNA binding
ahydratedamorphousironoxidenanoparticleasactivewateroxidationcatalyst
No full text由于传统化石燃料的不可再生性和使用过程中对环境的污染,近年通过太阳光驱动催化水分解制备氢气或CO2还原制备甲醇等高能化学燃料是人工光合作用制备太阳能燃料领域的研究重点.水的氧化反应是制备太阳能燃料的重要半反应,为质子或CO2的还原提供必需的质子和电子,开发基于非贵金属氧化物的高效水氧化催化剂是人工光合作用制备太阳能燃料的重要挑战之一.最近我们课题组的研究发现,无定形氧化钴作为水氧化催化剂时,其本征活性比结晶态的高出一个数量级.与氧化钴催化剂相比,铁基氧化物作为水氧化催化剂具有许多优点,比如成本低、环境友好、对动植物不产生生理毒性.基于此,本文探索了开发制备具有高催化活性的铁基氧化物作为水氧化催化剂.结果发现,氧化铁水氧化催化剂活性不但受其结晶度影响,还与其水合状态密切相关.水合氧化铁在进行室温真空干燥脱水处理后,在Ru(bpy)3^2+-Na2S2O8光催化水氧化体系中,其催化水氧化活性降低了一个数量级.热重分析、XRD和拉曼测试等结果表明,室温下进行脱水处理后,氧化铁基本不含有水分子的信号,其体相结构没有发生显著的变化.XRD和拉曼结果表明,催化水氧化测试后回收的氧化铁催化剂结构没有发生改变,表明该水合状态的氧化铁是水氧化过程中真实的催化剂成分,并不是充当前驱体的角色.基于此,我们进一步制备了尺寸较小且为水合状态的无定形氧化铁纳米粒子,后者在Ru(bpy)3^2+-Na2S2O8光催化水氧化体系中显示出极高的催化活性,TOF值高达9.3 s^-1,基于产生的氧气分子计算的光催化量子效率达到67%.该尺寸较小的水合状态氧化铁纳米粒子还可以有效地负载在SiO2表面进行催化水氧化反应,循环测试结果表明,负载的水合状态氧化铁纳米粒子连续进行三个催化水氧化循环测试,其活性未明显衰减,显示了较高的稳定性.该结果表明,未来设计铁基氧化物作为高活性的水氧化催化剂时,需要特别考虑其水合状态
activitypromotionofantisinteringaugmgga2o4usingceriainthewatergasshiftreactionandcatalyticcombustionreactions
No full textHeterogeneous gold nanocatalysts have both inspired researchers with their unique catalytic performance and frustrated them due to the contradictions observed in their activities and stabilities. a recent breakthrough has shown that gold nanoparticles (nps) can retain their catalytically active size over a mgga2o4 spinet support upon sintering at high temperatures. herein, we report the catalytic activity of anti-sintering augmgga(2)o(4) for use in water gas shift reaction (wgsr) and catalytic combustion reactions, and the promoting effect of ceria. upon adding ceria to 800 degrees c-aged augmgga(2)o(4), the co conversion in the wgsr was increased from similar to 1.5% to similar to 34.0% at 450 degrees c, and the "light-off" temperatures (t-50) for methane combustion and co oxidation were decreased by similar to 80 and similar to 100 degrees c, respectively. characterizations using xrd, haadf-stem, eds mapping, h-2-tpr, xps, and drifts confirmed the proximate contact of au with ceria and their significant synergistic effect, which thereby combined the benefits of ceria toward the dissociation of h2o or o-2 and the au nps toward activating co or ch4. these results show that this stepwise stabilization-activation strategy is efficient for rationally constructing stable and active gold nanocatalysts, which may open up possibilities for the wide application of gold nanocatalysts at elevated temperatures. (c) 2019, dalian institute of chemical physics, chinese academy of sciences. published by elsevier b.v. all rights reserved
Analysis of oligonucleotides by ion-pair reversed-phase liquid chromatography coupled with positive mode electrospray ionization mass spectrometry
No full textOligonucleotides are usually analyzed by ion-pair reversed-phase liquid chromatography (IP-RPLC) coupled with negative mode electrospray ionization mass spectrometry (ESI-MS) due to their highly negative charged phosphodiester backbones. Herein, the signal suppression effect of triethylamine (TEA) adducts caused the ion-pair reagent TEA/hexafluoroisopropanol (HFIP) is greatly alleviated after improving the in-source energy in positive mode ESI-MS. This strategy is applied for different RNA sequencing through analyzing their formic acid hydrolysates via IP-RPLC MS. Comparing with negative ion mode, we demonstrate that IP-RPLC MS analysis in positive ion mode is more suitable for RNA sequencing with fewer contaminant interferences. Finally, simultaneous online separation and detection of oligonucleotides and protein digests are achieved in positive ion mode IP-RPLC MS analysis with little interference to each other