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51.
N. Kallay M. Čolić D. W. Fuerstenau H. M. Jang E. Matijević 《Colloid and polymer science》1994,272(5):554-561
Potentiometric, electrokinetic, and coagulation experiments with a rutile dispersion in the pH region above the point of zero charge exhibit an inverse lyotropic sequence for counterions: Li+>K+>Cs+. The potentiometric and electrokinetic data were interpreted by a surface complexation model assuming the Stern-Gouy-Chapman structure of the interfacial layer, which yielded the values of inner layer capacitances,C, and the intrinsic equilibrium constants,K
ass
0
, characterizing the specificity of each counterion. These parameters were used to explain the order of lyotropic sequences in the adsorption, coagulation, and electrokinetic phenomena. 相似文献
52.
d-wave superconductor as a model of high-Tc superconductors 总被引:1,自引:0,他引:1
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54.
Silver ions dissolved in a polymer matrix are additionally coordinated by carbonyl oxygens of asparagines and their counter anions interact with cationic sites, resulting in the enhanced activity of the silver ion as an olefin carrier for facilitated olefin transport. 相似文献
55.
56.
Won Sick Woo Sam Sik Kang Otto Seligmann V. Mohan Chari Hildebert Wagner 《Tetrahedron letters》1980,21(44):4255-4258
From the seeds of Phytolacca americana two new lignans, Americanin B and D, have been isolated and their structures elucidated mainly by spectroscopic methods 相似文献
57.
Jang MJ Lee MJ Park HY Bae YS Min DS Ryu SH Kwak JY 《Experimental & molecular medicine》2004,36(2):172-178
Agents that elevate cellular cAMP are known to inhibit the activation of phospholipase D (PLD). We investigated whether PLD can be phosphorylated by cAMP-dependent protein kinase (PKA) and PKA-mediated phosphorylation affects the interaction between PLD and RhoA, a membrane regulator of PLD. PLD1, but not PLD2 was found to be phosphorylated in vivo by the treatment of dibutyryl cAMP (dbcAMP) and in vitro by PKA. PKA inhibitor (KT5720) abolished the dbcAMP-induced phosphorylation of PLD1, but dibutyryl cGMP (dbcGMP) failed to phosphorylate PLD1. The association between PLD1 and Val14RhoA in an immunoprecipitation assay was abolished by both dbcAMP and dbcGMP. Moreover, RhoA but not PLD1 was dissociated from the membrane to the cytosolic fraction in dbcAMP-treated cells. These results suggest that both PLD1 and RhoA are phosphorylated by PKA and the interaction between PLD1 and RhoA is inhibited by the phosphorylation of RhoA rather than by the phosphorylation of PLD1. 相似文献
58.
Won Ok Choi Mitsuo Sawamoto Toshinobu Higashimura 《Journal of polymer science. Part A, Polymer chemistry》1990,28(11):2923-2935
In the living cationic polymerization of isobutyl vinyl ether (IBVE) initiated by the hydrogen iodide/zinc halide (HI/ZnX2; X = I, Br, Cl) systems, the concentration ([P*]) of the living propagating species was determined by quenching with sodiomalonic ester ( 1 ). The quenching reaction was shown to be clean, instantaneous, and quantitative to give poly (IBVE) with a terminal malonate group from which [P*] was obtained by 1H-NMR spectroscopy. In the polymerizations in toluene below +25°C, [P*] was constant and equal to the initial concentration ([HI]0) of hydrogen iodide, independent of the type and concentrations of ZnX2 as well as monomer conversion. At 0 and +25°C, however, the living species started decaying immediately after the complete consumption of monomer. In contrast, such a decay process was absent at ?15°C even in the absence of monomer until about an hour (depending on the conditions) after the end of polymerization. The deactivation reaction was first order in [P*], and the lifetime (half-life) of the living species was longer at lower temperature and at lower ZnX2 concentration. On the basis of these [P*] and lifetime measurements, the HI/ZnX2 systems were also compared with the HI/I2 counterpart. 相似文献
59.
[reaction: see text]. Highly enantioenriched quaternary centers are obtained by the reaction of chiral lithiated intermediates complexed to (-)-sparteine with tetrasubstituted, alpha,alpha-dinitrile activated olefins. Lithiated N-Boc-N-Aryl benzylamine furnishes products with drs from 78:22 to 95:5, with ers exceeding 94:6. Lithiated N-Boc-N-Aryl allylamine reactants provide enecarbamate products with drs from 55:45 to 99:1, with ers ranging from 87:13 to 97:3. 相似文献
60.
Cell lysis was demonstrated on a microfluidic CD (Compact Disc) platform. In this purely mechanical lysis method, spherical particles (beads) in a lysis chamber microfabricated in a CD, cause disruption of mammalian (CHO-K1), bacterial (Escherichia coli), and yeast (Saccharomyces cerevisiae) cells. Interactions between beads and cells are generated in the rimming flow established inside a partially filled annular chamber in the CD rotating around a horizontal axis. To maximize bead-cell interactions in the lysis chamber, the CD was spun forward and backwards around this axis, using high acceleration for 5 to 7 min. Investigation on inter-particle forces (friction and collision) identified the following parameters; bead density, angular velocity, acceleration rate, and solid volume fraction as having the most significant contribution to cell lysis. Cell disruption efficiency was verified either through direct microscopic viewing or measurement of the DNA concentration after cell lysing. Lysis efficiency relative to a conventional lysis protocol was approximately 65%. In the long term, this work is geared towards CD based sample-to-answer nucleic acid analysis which will include cell lysis, DNA purification, DNA amplification, and DNA hybridization detection. 相似文献