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Effect of lanthanum ions on tRNA^(Phe) structure: Imino proton NMR spectroscopy 被引量:1
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作者 TU Huamin WU Yijie +2 位作者 YANG Yansheng GONG Menglian ZHANG Hongjie 《Chinese Science Bulletin》 SCIE CAS 1998年第6期490-493,共4页
The effect of lanthanum ions on the structural and conformational change of yeast tRNA Phe was studied by 1H NMR. The results suggest that the tertiary base pair (G-15)(C-48), which was located in the terminal in the ... The effect of lanthanum ions on the structural and conformational change of yeast tRNA Phe was studied by 1H NMR. The results suggest that the tertiary base pair (G-15)(C-48), which was located in the terminal in the augmented dihydrouridine helix (D-helix), was markedly affected by adding La 3+ and shifted 0.33 downfield. Based pair (U-8)(A-14), which is associated with a tertiary interaction, links the base of the acceptor stem to the D-stem and anchors the elbow of the L structure, shifted 0.20 upfield. Another imino proton that may be affected by La 3+ in tRNA Phe is the tertiary base pair (G-19)(C-56). The assignment of this resonance is tentative since it is located in the region of highly overlapping resonances between 12.6 and 12.2. This base pair helps to anchor the D-loop to the TΨC loop. 展开更多
关键词 lanthanum ion transfer ribonucleic acid NMR.
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Effect of lanthanum ion implantation on oxidation behavior of zircaloy 被引量:1
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作者 XiaoyangLiu XindeBai 《Journal of University of Science and Technology Beijing》 CSCD 2004年第3期260-262,共3页
In order to investigate the effect of lanthanum ion implantation on theoxidation behavior of zircaloy at 500℃, Zircaloy specimens were implanted by lanthanum ions with adose range from 5xl0^(16) to 2xl0^(17) ions/cm^... In order to investigate the effect of lanthanum ion implantation on theoxidation behavior of zircaloy at 500℃, Zircaloy specimens were implanted by lanthanum ions with adose range from 5xl0^(16) to 2xl0^(17) ions/cm^2 at room temperature, and then oxidized at 500℃ for100 min. The valence of the oxides in the scale was analyzed by X-ray Photoelectron Spectroscopy(XPS). The phase structures of the oxides in the scale were examined by Glancing Angle X-rayDiffraction (GAXRD). With the increase of implanted lanthanum ions dose, the phase structures in theoxide scale are transformed from monoclinic zirconia to hexagonal one and then to monoclinic oneagain. The measurement of weight gain showed that a similar change from the decreased gain toincreased one again is achieved in the oxidation behavior of lanthanum ion implanted zircaloycompared with that of as-received zircaloy. 展开更多
关键词 ZIRCALOY air oxidation lanthanum ion implantation hexagonal zirconia monoclinic zirconia phase transformation
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Preparation and Properties of Lanthanum Trivalent Ion Doped TiO_2 Nanopowders by Liquid Plasma Spray 被引量:1
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作者 徐大鹏 冯拉俊 +1 位作者 雷阿利 朱广 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第S1期570-574,共5页
The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatal... The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatalytic activity of samples at different doping concentrations in photocatalytic degradation of methyl orange was discussed. The powders were characterized by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD), and the effect of doped ion on the pattern, phase composition and crystallite sizes were analyzed. The results indicated that lanthanum trivalent ion doped TiO2 nanopowders could be prepared by liquid plasma spray. Lanthanum trivalent ion doping increased the photocatalytic activity of TiO2 greatly, the optimal doping concentration was 0.5%. The doped powders were the mixture of anatase phase and rutile phase. The contents of anatase phase decreased firstly and then increased with an increase in the contents of lanthanum trivalent ion. Doping lanthanum trivalent ion could make the TiO2 nanopowders uniform and reduced its particle size. 展开更多
关键词 TiO_2 photocatalyst liquid plasma spray lanthanum trivalent ion doping rare earths
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Facile and Efficient Method for the Adsorption and Separation of Lanthanum Rare Earth Metal Oxide Using Iron(Ⅱ) Sulfide Nanoparticles Coated on Magnetite
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作者 Siyamak Bagheriyan 《Journal of Chemistry and Chemical Engineering》 2011年第9期824-827,共4页
A novel iron sulphide adsorbent using magnetite embedded with nanosized Fe3O4 was prepared and applied to separation lanthanum (Ⅲ) from aqueous solution. This adsorbent combines the advantages of magnetic nanoparti... A novel iron sulphide adsorbent using magnetite embedded with nanosized Fe3O4 was prepared and applied to separation lanthanum (Ⅲ) from aqueous solution. This adsorbent combines the advantages of magnetic nanoparticle with magnetic separability and high affinity toward rare earth metals, which provides distinctive merits including easy preparation, high adsorption capacity, easy isolation from sample solutions by the application of an external magnetic field. The adsorption behaviors of lanthanum (Ⅲ) from an aqueous medium, using iron sulphide magnetite nanoparticles were studied using equilibrium batch and column flow techniques. The effect ofpH, contents of loaded iron sulphide nanoparticles, ionic strength, adsorbent dose, contact time, and temperature on adsorption capacity of the magnetic beads was investigated. All of the results suggested that the FeS/Fe3O4 Nanoparticles could be excellent adsorbents for La(Ⅲ) contaminated water treatment. 展开更多
关键词 nano magnetite lanthanum ion Adsorption.
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Adsorption of Rare Earth Ion La(Ⅲ) on Yunnan Bowl Tea Surface from Aqueous Solution
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作者 木冠南 周俊 +1 位作者 唐丽斌 赵天培 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第S1期23-27,共5页
The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb ... The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb strongly La(Ⅲ) and pH may affect drastically the adsorption amount of La(Ⅲ). The adsorption law of La(Ⅲ) on Yunnan bowl tea surface follows the Langmuir equation. The maximum adsorption amount of La(Ⅲ) can reach 15 mg·g (-1). A comprehensive adsorption model is suggested according to the experimental results. 展开更多
关键词 Yunnan bowl tea ADSORPTION lanthanum(Ⅲ) ion surfactant rare earths
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Lanthanum chloride promotes proliferation of NIH 3T3 cells via cell cycle machinery
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作者 潘鑫 李金霞 +4 位作者 董发勤 邓建军 袁兰 王夔 余四旺 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2013年第1期64-70,共7页
Lanthanum ions (La3+) have been reported to exert profound effects on the proliferation of NIH 3T3 mouse embryonic fibroblasts. In the present studies, the pro-proliferative effect of La3+ on NIH 3T3 cells was fur... Lanthanum ions (La3+) have been reported to exert profound effects on the proliferation of NIH 3T3 mouse embryonic fibroblasts. In the present studies, the pro-proliferative effect of La3+ on NIH 3T3 cells was further characterized, and its impacts on the cell cycle kinetics were analyzed in detail by cell cycle arrest-and-release and pulse BrdU-labeling and chasing experiments. The results show that La3+ promoted the proliferation of NIH 3T3 cells after 12 h and the ECs0 was 2.4 ktM after 48 h. Such effect was also confirmed by enhanced BrdU incorporation. La3+ stimulated more cells to pass through the G1/S checkpoint into S phase, but did not change the length of cell cycle. Furthermore, La3+-treatment increased the protein levels and nuclear localization of cyclin D 1 and c-Myc, two key regulators of G1/S checkpoint, as demonstrated by immunostaining. The pro-proliferative effects of La3+ share striking similarity with that of Gd3+, and provided new information regarding the cellular biological activities of lanthanides. 展开更多
关键词 lanthanum ions NIH 3T3 cells PROLIFERATION Cell cycle Cyclin D 1 C-MYC
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Rapid Phosphodiester Hydrolysis Catalyzed by Lanthanum(Ⅲ)
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作者 寇兴明 胡艳 +2 位作者 黄忠 孟祥光 曾宪诚 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2005年第10期1303-1308,共6页
The catalytic hydrolysis of bis(4-nitrophenyl)phosphate (BNPP) by lanthanum(Ⅲ) ion in the presence of amino-alcoholic ligands: diethanolamine (DEA) and triethanolamine (TEA), was investigated kinetically a... The catalytic hydrolysis of bis(4-nitrophenyl)phosphate (BNPP) by lanthanum(Ⅲ) ion in the presence of amino-alcoholic ligands: diethanolamine (DEA) and triethanolamine (TEA), was investigated kinetically at 30 ℃. The results indicated that the dinuclear dihydroxo complexes formed by lanthanum(Ⅲ) ion with aminoalcoholic ligands might be the catalytically active species which catalyze the hydrolysis of BNPP to different extents and the catalytic mechanism was believed to involve the synergism of double Lewis acid activation of the substrate and an intramolecular nucleophilic attack of a bridging oxo ligand. 展开更多
关键词 PHOSPHODIESTER HYDROLYSIS lanthanum(Ⅲ) ion amino-alcohol artificial nuclease kinetics
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Transfer of lanthanum ion across the adsorption of emulsifier OP at the water-nitrobenzene interface
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作者 狄俊伟 蔡红兰 范瑞溪 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1998年第2期138-144,共7页
The transfer of lanthanum ion facilitated by diantipyrylmethane (DAM) across the water/nitrobenzene (w/nb) interface and the adsorption of emulsifier OP at the w/nb interface has been studied by the cyclic voltammetry... The transfer of lanthanum ion facilitated by diantipyrylmethane (DAM) across the water/nitrobenzene (w/nb) interface and the adsorption of emulsifier OP at the w/nb interface has been studied by the cyclic voltammetry. The mechanism of the charge transfer reactions is discussed. It has been concluded that the transfer of rare earth metal ion (La3+) facilitated by neutral ionophore (DAM) at the w/nb interface is E mechanism and the nonionic surfactant (emulsifier OP) can participate in the charge transfer process M an ionophore, charge transfer catalyst and inhibitor. 展开更多
关键词 Cyclic voltammetry liquid/liquid interface lanthanum ion emulsifier OP
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Effects of La^(3+)on yield and quality traits of wheat with different gluten types 被引量:8
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作者 欧红梅 张自立 姚大年 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第7期672-680,共9页
To test the roles of La3+ on yield and quality of wheat for different end uses, experiments were conducted using split-plot design for different La3+ treatments as main plot and different gluten types of wheat as su... To test the roles of La3+ on yield and quality of wheat for different end uses, experiments were conducted using split-plot design for different La3+ treatments as main plot and different gluten types of wheat as subplot, by foliar spraying La3+ at jointing stage and filling stage. The results showed that spraying 0.5–1.5 mmol/L La3+ increased the yield and 1000-kernel weight of wheat of different gluten types. The protein content of strong-gluten wheat Wanmai 33 increased after spraying 0.5–1.5 mmol/L La3+, which made it achieve the good quality standard of strong-gluten wheat, whereas its LOX and PPO activity reduced, the carotenoid content increased. These La3+ treatments prolonged the storage period of grain, improved flour nutritional value and the food processing quality. Spraying 0.5–1.5 mmol/L La3+ also increased flour peak viscosity of medium-gluten wheat Yangmai 158, as improving its starch properties. Spraying La3+ significantly decreased flour water absorption rate of weak gluten type variety Wanmai 48 to meet the weak-gluten flour standard. The total pentosan content reduced at 1–1.5 mmol/L La3+, which would be good for making biscuit. Results suggested that spraying appropriate concentration of La3+ increased wheat yield and benefited wheat quality for different end uses. 展开更多
关键词 lanthanum ion gluten type yield quality trait wheat for different end uses rare earths
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La^(3+) -doped SrBi_2Ta_2O_9 thin films for FRAM synthesized by sol-gel method
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作者 V.V.Sidsky A.V.Semchenko +4 位作者 A.G.Rybakov V.V.Kolos A.S.Turtsevich A.N.Asadchyi W.Strek 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第3期277-281,共5页
This paper discusses the possibility of synthesis of SBTL sol-gel films for use as active layers for non-volatile memory (FRAM). La-doped SrBi2Ta209 thin films were synthesized by sol-gel method on Pt/TiO2/BPSG/SiO2... This paper discusses the possibility of synthesis of SBTL sol-gel films for use as active layers for non-volatile memory (FRAM). La-doped SrBi2Ta209 thin films were synthesized by sol-gel method on Pt/TiO2/BPSG/SiO2/Si substrates. The structural features of the surface (AFM), crystallization behavior (XRD) during the heating and ferroelectric properties of synthesized films were discussed. It was shown that an optimum surface structure and a high share of perovskite phase of SBTL-films were compared to SBT-films (Theating=800 ℃). Achieved ferroelectric parameters suggested the possibility of using synthesized SBTL sol-gel films in non-volatile memory devices. 展开更多
关键词 ferroelectric thin films sol-gel method lanthanum ion non-volatile memory rare earths
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