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121.
S. C. Chae Y. N. Jang I. K. Bae K. W. Ryu T. S. Yudintseva S. V. Yudintsev 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):73-77
This study was aimed at the synthesis, study of phase relations and characterization of the garnet ([Ca1.5GdCe0.5]VIII[ZrFe]VI[Fe
x
Al3−x
]IVO12, x = 0−2) intended as promising matrix for actinides (Pu) immobilization. The optimum temperatures of the fabrication of the
garnets ceramics are 1400 °C at x = 2 and 1500 °C at x = 0−1. The garnets lattice parameters and the content of Ce, as an imitator of Pu, increased with the content of iron. It
was suggested that the ability of the garnet for incorporation of Pu was closely related to the ionic radii of the elements
occupied the four-and six-coordinated sites of the structure. 相似文献
122.
Iranzo O Thulstrup PW Ryu SB Hemmingsen L Pecoraro VL 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(33):9178-9190
The use of de novo designed peptides is a powerful strategy to elucidate Hg(II)-protein interactions and to gain insight into the chemistry of Hg(II) in biological systems. Cysteine derivatives of the designed alpha-helical peptides of the TRI family [Ac-G-(L(a)K(b)A(c)L(d)E(e)E(f)K(g))(4)-G-NH(2)] bind Hg(II) at high pH values and at peptide/Hg(II) ratios of 3:1 with an unusual trigonal thiolate coordination mode. The resulting Hg(II) complexes are good water-soluble models for Hg(II) binding to the protein MerR. We have carried out a parallel study using (199)Hg NMR and (199m)Hg perturbed angular correlation (PAC) spectroscopy to characterize the distinct species that are generated under different pH conditions and peptide TRI L9C/Hg(II) ratios. These studies prove for the first time the formation of [Hg{(TRI L9C)(2)-(TRI L9C-H)}], a dithiolate-Hg(II) complex in the hydrophobic interior of the three-stranded coiled coil (TRI L9C)(3). (199)Hg NMR and (199m)Hg PAC data demonstrate that this dithiolate-Hg(II) complex is different from the dithiolate [Hg(TRI L9C)(2)], and that the presence of third alpha-helix, containing a protonated cysteine, breaks the symmetry of the coordination environment present in the complex [Hg(TRI L9C)(2)]. As the pH is raised, the deprotonation of this third cysteine generates the trigonal thiolate-Hg(II) complex Hg(TRI L9C)(3)(-) on a timescale that is slower than the NMR timescale (0.01-10 ms). The formation of the species [Hg{(TRI L9C)(2)(TRI L9C-H)}] is the result of a compromise between the high affinity of Hg(II) to form dithiolate complexes and the preference of the peptide to form a three-stranded coiled coil. 相似文献
123.
Synthesis of aligned single-walled nanotubes using catalysts defined by nanosphere lithography 总被引:1,自引:0,他引:1
Ryu K Badmaev A Gomez L Ishikawa F Lei B Zhou C 《Journal of the American Chemical Society》2007,129(33):10104-10105
124.
Kang HM Ryong Kim J Jeong TS Choi SG Ryu YH Taeg Oh G Baek NI Kwon BM 《Natural product research》2006,20(2):139-143
Two cyclic diarylheptanoids, garugamblin-3 (1) and acerogenin L (2), isolated from the MeOH extract of the fruits of Alnus japonica Steud., inhibited human low-density lipoprotein (LDL) oxidation in the thiobarbituric acid-reactive substance assay with IC50 values of 2.9 and 1.7 microM, respectively, and they also inhibited cell-mediated LDL oxidation more than five times more strongly than that of a well-known antioxidant, probucol, at a concentration of 10 microM. 1 had no effect on the anti-atherogenesis in low-density lipoprotein receptor- deficient mice. 相似文献
125.
Kim J Ryu D Sei Y Yamaguchi K Ahn KH 《Chemical communications (Cambridge, England)》2006,(10):1136-1138
Homochiral coordination cages, which have two well-defined internal binding sites for ammonium and organoammonium ions, have been constructed by Pd(II)-mediated self-assembly of preorganized tripodal oxazolines containing pyridine pendant groups. 相似文献
126.
127.
Jin-Woong?Kim Jin-Gyu?Park Jee-Hyun?Ryu Ih-Seop?Chang Kyung-Do?SuhEmail author 《Colloid and polymer science》2005,283(11):1233-1240
This study presents a method to produce monodisperse chloromethyl-functionalized macroporous poly(styrene-co-divinylbenzene) polymer particles by seeded polymerization in aqueous media. We observed that the molecular structure of
polystyrene seed particles, the composition of the secondary monomer mixtures, and the type of solvents were very important
factors that determine the morphology and porosity of the final particles. This study proposes that the molecular chemistry
of polystyrene seed polymers, increasing molecular weight or crosslinking, is another factor that can control the porosity
of the final particles. Also, the selection of a poor solvent was effective in forming the larger surface area. In this study,
it was confirmed that the chloromethyl groups introduced on the surface of porous particles were quantified chemically and
their effective incorporation had a close relationship with the surface area. 相似文献
128.
Sung‐Nak Choi Sang‐Yub Kim Hae‐Wook Ryu Yong‐Min Lee 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(12):m504-m506
In the title compound, [HgCl2(C15H26N2)], the chiral alkaloid (6R,7S,8S,14S)‐(−)‐l ‐sparteine acts as a bidentate ligand, with two Cl− ligands occupying the remaining coordination sites, producing a distorted tetrahedron. The N—Hg—N plane is twisted by 81.1 (2)° from the Cl—Hg—Cl plane. The mid‐point of the N⋯N line does not lie exactly on the Cl—Hg—Cl plane but is tilted towards one of the N atoms by 0.346 Å. Similarly, the mid‐point of the Cl⋯Cl line is tilted toward one of the Cl atoms by 0.163 Å. The packing structure shows that the complex is stabilized by two interatomic Cl⋯H contacts involving both Cl atoms and the methylene or methine H atoms of the (−)‐sparteine ligand. 相似文献
129.
Sung-Sik You Hyeong-Won Ryu Young Cho Dae-Young Kim Thong-Sung Ko 《Reaction Kinetics and Catalysis Letters》1999,66(1):121-126
The nonenzymatic hydrolysis of RNA by polyvinylpyrrolidone (PVP) has been investigated. A bell-shaped kinetics was observed
when the first order rate constant of the reaction was ploted as a function of PVP concentration, which means the kinetic
feature of PVP as a degradative receptor distinct from those of degradative enzymes (e.g., ribonuclease). 相似文献
130.