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181.
Shilin Jiang Dr. Jianhui Lan Dr. Lin Wang Dr. Yalan Liu Yuke Zhong Yichuan Liu Dr. Liyong L.-Y. Yuan Dr. Lirong Zheng Prof. Zhifang Chai Prof. Weiqun Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(45):11721-11729
Molten salt electrolysis is a vital technique to produce high-purity lanthanide metals and alloys. However, the coordination environments of lanthanides in molten salts, which heavily affect the related redox potential and electrochemical properties, have not been well elucidated. Here, the competitive coordination of chloride and fluoride anions towards lanthanide cations (La3+ and Nd3+) is explored in molten LiCl-KCl-LiF-LnCl3 salts using electrochemical, spectroscopic, and computational approaches. Electrochemical analyses show that significant negative shifts in the reduction potential of Ln3+ occur when F− concentration increases, indicating that the F− anions interact with Ln3+ via substituting the coordinated Cl− anions, and confirm [LnClxFy]3−x−y (ymax=3) complexes are prevailing in molten salts. Spectroscopic and computational results on solution structures further reveal the competition between Cl− and F− anions, which leads to the formation of four distinct Ln(III) species: [LnCl6]3−, [LnCl5F]3−, [LnCl4F2]3− and [LnCl4F3]4−. Among them, the seven-coordinated [LnCl4F3]4− complex possesses a low-symmetry structure evidenced by the pattern change of Raman spectra. After comparing the polarizing power (Z/r) among different metal cations, it was concluded that Ln−F interaction is weaker than that between transition metal and F− ions. 相似文献
182.
LaxBa1—xCoO3系导电陶瓷导电性研究 总被引:1,自引:1,他引:1
对LaxBa1-xCoO导电陶瓷的导电性及其导电机制进行了研究,在x=0.5mol处,导电陶瓷具有金属态导是性,在La0.5Ba0.5CoO3陶瓷中,存在着氧缺位和导电电子,并且此种导电陶瓷具有较高的电子和氧离子混合导电特性。 相似文献
183.
阿斯美胶囊中四种组分的高效液相色谱分析 总被引:2,自引:0,他引:2
建立了反相高效液相色谱法测定阿斯美胶囊中氨茶碱、盐酸甲氧非那明、马来酸氯苯那敏及那可汀四种组分的含量。色谱柱为SpherisorbC8,5μm,200cm×40mmID,流动相为体积分数05%的三乙胺溶液(磷酸调节pH55)+乙腈+甲醇(550+368+82),检测波长为264nm,线性范围分别为:氨茶碱3125~250mg/L,γ=09996,盐酸甲氧非那明15625~1250mg/L,γ=10000,马来酸氯苯那敏25~200mg/L,γ=09999,那可汀875~700mg/L,γ=09999;回收率(n=3)分别为1012%,1008%,999%,995%;精密度:日内平均RSD(n=6)分别为07%,04%,04%,06%;日间平均RSD(n=3)分别为10%,10%,11%,12%。 相似文献
184.
185.
We optimized the hot water extraction of polysaccharides from the root of Henry wood betony (RHWPs) using a uniform test and explored their anti-tumor activities in vitro and in vivo. The optimal extraction conditions were as follows: 40 min extraction time, liquid/solid ratio 30 mL/g, 100 min soaking time, two extraction cycles, 100% ethanol concentration, and extraction temperature of 80 °C. The molecular weight distribution of RHWPs with MWs was 228,600 g/mol and 5001 g/mol. The IR spectrum further indicated that RHWPs are acidic polysaccharides containing pyranose and furan rings. The main monosaccharides found in RHWPs were mannose, ribose, l-rhamnose monohydrate, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose, and fucose. RHWPs inhibited the proliferation of S180 tumor cells and induced apoptosis in vitro. Oral administration of RHWPs to tumor-bearing mice significantly inhibited the growth of the S180 xenografts, accelerated apoptosis in tumor cells, and expanded the necrotic regions. Furthermore, RHWPs also markedly increased the levels of TNF-α, IFN-γ, and IL-2 in the sera of tumor-bearing mice, and activated immune cells such as lymphocytes, NK cells, and macrophages, thereby inducing tumor cell apoptosis. Taken together, RHWPs are a promising anti-tumor agent that ought to be explored further. 相似文献
186.
L. M. Lopez Marin D. Promé M. A. Lanéelle M. Daffé J. C. Promé 《Journal of the American Society for Mass Spectrometry》1992,3(6):656-661
Mycobacteria contain species- and type-specific antigens. Among them, glycopeptidolipids are present in medically relevant organisms belonging to Mycobacterium avium or M. fortuitum complexes. Fast-a tom bombardment mass spectrometry of glycopeptidolipids has proven to be difficult. In this article the cationization method with a metanitrobenzyl alcohol matrix, doped with sodium iodide, is described for analyzing these molecules. The molecular weight of the intact glycopeptidolipids was successfully determined and, using mass-analyzed ion kinetic energy spectrometry, the complete sequences of the peptide and saccharide moieties were elucidated. Moreover, the two structural variants present in these molecules were clearly differentiated. Application of the method showed that the same structural variant occurs in the glycopeptidolipids from two serologically related species of the M. fortuitum complex. 相似文献
187.
A new oligothiophene-based sensor 3 TH for monitoring Hg2+ has been designed and synthesized based on the intramolecular charge transfer (ICT) mechanism. The 3 TH shows the significant specificity toward Hg2+ through “naked-eye” colorimetric detection as well as via ratiometric fluorescence enhancement response with low detection limit of 62 nM. In addition, sensor 3 TH shows high selectivity and sensitivity for Hg2+ with fast response in a suitable pH range. Moreover, the 3 TH-based test strips was used to conveniently detect Hg2+ ions in water. Furthermore, considering its good ‘‘turn-on’’ fluorescent sensing behavior and low cell cytotoxicity, 3 TH was successfully applied to detect and image Hg2+ in real water samples and living cells, which shows great potentials for application in environmental and biological systems. 相似文献
188.
Hou-Jin Li Cai-Wu Jiang Meng-Yang Xu Dan-Feng Yan Jun Xu Wen-Jian Lan 《Tetrahedron letters》2019,60(34):150953
Three sesquiterpenoids pseudapenes A–C (1–3) were isolated from the marine-derived fungus Pseudallescheria apiosperma F52-1. Pseudapene A (1) has an unprecedented 2-methyl-5-methylene-3-(2-methylbut-2-ene)-dicyclo(3, 3, 0)-octane carbon skeleton and pseudapenes B (2) and C (3) possess an unique 2-methyl-4-methylene-2-(2-methylpent-2-ene)-dicyclo(3, 2, 0)-heptane chemical scaffold. Their structures were determined by use of MS and NMR spectroscopic data, and ECD, optical rotation and 13C NMR calculations. 相似文献
189.
Enzymes are macromolecular biological catalysts which can accelerate chemical reactions in living organisms. Almost all the physiological metabolism activities in the cell need enzymes to sustain life via rapid catalysis. Currently, medical research has proved that abnormal enzyme activity is associated with numerous diseases, such as Parkinson’s disease (PD), Alzheimer's disease (AD) and cancers. On the other hand, early diagnosis of those diseases is of great significance to improve the survival rate and cure rate. In the current diagnostic tools, two-photon fluorescent probes (TPFPs) are developing rapidly due to their unique advantages, such as higher spatial resolution, deeper imaging depth, and lower biotoxicity. Therefore, the design and synthesis of two-photon (TP) small molecule enzymatic probes have broad prospects for early diagnosis and treatment of diseases. As of now, scientists have developed many TP small molecule enzymatic probes. This review aims to summarize the TP small molecule enzymatic probes and expound the reaction mechanism. 相似文献
190.
Nan Zhang Ming‐Yu Qi Lan Yuan Xianzhi Fu Zi‐Rong Tang Jinlong Gong Yi‐Jun Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(29):10108-10112
The efficiency of solar hydrogen evolution closely depends on the multiple electrons accumulation on the catalytic center for two‐electron‐involved water reduction. Herein, we report an effective approach to enable broadband light absorption and unidirectional electron flow for efficiently accumulating electrons at active sites for hydrogen evolution by rationally engineering the nanostructure of Pt nanoparticles (NPs), TiO2, and SiO2 support. In addition to Schottky‐junction‐driven electron transfer from TiO2 to Pt, Pt NPs also produce hot electrons by recycling the scattered visible and near‐infrared (vis‐NIR) light of the support. Unidirectional electron flow to active sites is realized by tuning the components spatial distribution. These features collectively accumulate multiple electrons at catalytic Pt sites, thereby affording enhanced activity toward hydrogen evolution under simulated sunlight. 相似文献