To design novel phenanthroline-derived soft ligands for selectively separating minor actinides from lanthanides, four tetradentate phenanthroline-derived heterocyclic ligands(BTPhen, BPyPhen, BPzPhen, and BBizPhen) we...To design novel phenanthroline-derived soft ligands for selectively separating minor actinides from lanthanides, four tetradentate phenanthroline-derived heterocyclic ligands(BTPhen, BPyPhen, BPzPhen, and BBizPhen) were constructed and their complexation behaviors with Am(ⅡI) and Eu(ⅡI) were systematically investigated by density functional theory(DFT) coupled with relativistic small-core pseudopotential. In all the 1:1-type species, the metal ion is in the center of the cavity and coordinates with two nitrogen atoms(N1 and N1′) of the phenanthroline skeleton and the other two nitrogen atoms(N2 and N2′) of the auxiliary groups. The bond lengths of Am–N are comparable to or even shorter than those of Eu–N bonds because the ionic radii of Am(ⅡI) are larger than those of Eu(ⅡI). Additionally, the negative ΔΔGAm/Eu value for the reaction of [M(H2O)4-(NO3)3] + L → ML(NO3)3 + 4H2 O indicates that the complexation reaction of Am(ⅡI) is more energetically favorable than that of Eu(ⅡI); this can be considered as an important design criterion to screen phenanthroline-derived ligands for MA(ⅡI) extraction. According to this criterion, the selectivity of tetradentate phenanthroline-derived ligands for separating Am(ⅡI) over Eu(ⅡI) follows the order of BTPhen > BBizPhen > BPyPhen > BPzPhen.展开更多
文摘目的 随着我国快速步入老龄化时代,老年人成为入住医院最主要的群体,本研究旨在调查住院老年患者衰弱的危险因素并构建列线图,为住院患者的衰弱综合征预防提供科学的参考依据。方法 于2020年1月—2021年12月,采用便利抽样法抽取芜湖市2家医院共30个病区进行问卷调查,采用专人一对一采集问卷。其中,一般资料包括性别、年龄、文化水平、户籍、月收入、5年以上慢性病、跌倒、午睡、吸烟、饮酒、睡眠障碍、抑郁情绪。通过单因素分析,研究结果表明,睡眠障碍、抑郁、跌倒、5年以上慢性病、午睡等具有统计学意义(P<0.05)。通过R Studio 4.2.3软件构建风险因素的列线图,并且对模型进行相关验证。结果 住院老年患者在5年以上慢性病、跌倒、午睡、睡眠障碍及抑郁情绪具有统计学差异(P<0.05),5年以上慢性病、有跌倒史、有午睡习惯、有睡眠障碍和抑郁情绪是老年住院患者衰弱的独立危险因素,建立模型并绘制列线图,ROC曲线下面积(Area under curve,AUC)是0.822。结论 本研究通过构建老年住院患者衰弱风险预测模型预测性能较好,为本地区医院的医护工作者提前筛选衰弱发生的高风险人群,并可提前预判住院患者衰弱的发生提供参考依据。
基金supported by the Major Research Plan"Breeding and Transmutation of Nuclear Fuel in Advanced Nuclear Fission Energy System"of the National Natural Science Foundation of China(91326202,91126006)the National Natural Science Foundation of China(21201166,11275219,11105162,21261140335)+1 种基金the"Strategic Priority Research Program"of the Chinese Academy of Sciences(XDA030104)the China Postdoctoral Science Foundation(2013M530734)
文摘To design novel phenanthroline-derived soft ligands for selectively separating minor actinides from lanthanides, four tetradentate phenanthroline-derived heterocyclic ligands(BTPhen, BPyPhen, BPzPhen, and BBizPhen) were constructed and their complexation behaviors with Am(ⅡI) and Eu(ⅡI) were systematically investigated by density functional theory(DFT) coupled with relativistic small-core pseudopotential. In all the 1:1-type species, the metal ion is in the center of the cavity and coordinates with two nitrogen atoms(N1 and N1′) of the phenanthroline skeleton and the other two nitrogen atoms(N2 and N2′) of the auxiliary groups. The bond lengths of Am–N are comparable to or even shorter than those of Eu–N bonds because the ionic radii of Am(ⅡI) are larger than those of Eu(ⅡI). Additionally, the negative ΔΔGAm/Eu value for the reaction of [M(H2O)4-(NO3)3] + L → ML(NO3)3 + 4H2 O indicates that the complexation reaction of Am(ⅡI) is more energetically favorable than that of Eu(ⅡI); this can be considered as an important design criterion to screen phenanthroline-derived ligands for MA(ⅡI) extraction. According to this criterion, the selectivity of tetradentate phenanthroline-derived ligands for separating Am(ⅡI) over Eu(ⅡI) follows the order of BTPhen > BBizPhen > BPyPhen > BPzPhen.
