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991.
Liu ZC Yang ZY Li TR Wang BD Li Y Qin DD Wang MF Yan MH 《Dalton transactions (Cambridge, England : 2003)》2011,40(37):9370-9373
In the article, a novel fluorescent probe for the copper cation based on fluorescence quenching mechanism was designed. It exhibited high selectivity for Cu(II) over other common metal ions in aqueous media. Furthermore the coordination between Cu(II) and the organic molecule sensor fabricated an interesting 1D chain coordination polymer framework. 相似文献
992.
Lou Z Huang B Wang P Wang Z Qin X Zhang X Cheng H Zheng Z Dai Y 《Dalton transactions (Cambridge, England : 2003)》2011,40(16):4104-4110
The near-spherical AgCl micro-crystals were prepared by an ionic liquids-assisted hydrothermal method. The influence of ionic liquids (C(x)MimCl x = 4, 8, 12, 16) on (001) facet growth of AgCl was studied systemically. The composition of the as-prepared samples was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and FTIR spectra. The morphological structures were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Based on experimental data and the classical crystal growth theory, a plausible growth mechanism of the near-spherical AgCl was proposed. The plasmonic photocatalyst Ag@AgCl prepared from the near-spherical AgCl showed higher activity than that of cubic morphologies. 相似文献
993.
Tetrabutylammonium chloride (TBACl) salt alone has not been shown previously to be capable of removing methoxy groups. It is demonstrated here that the use of TBACl achieves efficient folding-promoted chemo- and regioselective demethylations, eliminating up to two out of five methyl groups situated in similar macrocyclic chemical microenvironments. 相似文献
994.
Wu D Wang Q Assary RS Broadbelt LJ Krilov G 《Journal of chemical information and modeling》2011,51(7):1634-1647
We present a new computational strategy for the design and evaluation of novel enzymatic pathways for the biosynthesis of fuels and chemicals. The approach combines the use of the Biochemical Network Integrated Computational Explorer (BNICE) framework and a structure-based screening method for rapid generation and evaluation of novel enzymatic reactions and pathways. The strategy is applied to a case study of 1-butanol production from pyruvate, which yielded nine novel biosynthetic pathways. Using screening criteria based on pathway length, thermodynamic feasibility, and metabolic flux analysis, all nine novel pathways were deemed to be attractive candidates. To further assess their feasibility of implementation, we introduced a new screening criterion based on structural complementarity using molecular docking methods. We show that this approach correctly reproduces the native binding poses for a wide range of enzymes in key classes related to 1-butanol production and provides qualitative agreement with experimental measures of catalytic activity for different substrates. In addition, we show that the structure-based methods can be used to select specific proteins that may be promising candidates to catalyze novel reactions. 相似文献
995.
Ren J Qin H Wang J Luedtke NW Wang E Wang J 《Analytical and bioanalytical chemistry》2011,399(8):2763-2770
In this study we have used two fluorescent probes, tetrakis(diisopropylguanidino)-zinc-phthalocyanine (Zn-DIGP) and N-methylmesoporphyrin IX (NMM), to monitor the reassembly of “split” G-quadruplex probes on hybridization with an arbitrary
“target” DNA. According to this approach, each split probe is designed to contain half of a G-quadruplex-forming sequence
fused to a variable sequence that is complementary to the target DNA. Upon mixing the individual components, both base-pairing
interactions and G-quadruplex fragment reassembly result in a duplex–quadruplex three-way junction that can bind to fluorescent
dyes in a G-quadruplex-specific way. The overall fluorescence intensities of the resulting complexes were dependent on the
formation of proper base-pairing interactions in the duplex regions, and on the exact identity of the fluorescent probe. Compared
with samples lacking any “target” DNA, the fluorescence intensities of Zn-DIGP-containing samples were lower, and the fluorescence
intensities of NMM-containing samples were higher on addition of the target DNA. The resulting biosensors based on Zn-DIGP
are therefore termed “turn-off” whereas the biosensors containing NMM are defined as “turn-on”. Both of these biosensors can
detect target DNAs with a limit of detection in the nanomolar range, and can discriminate mismatched from perfectly matched
target DNAs. In contrast with previous biosensors based on the peroxidase activity of heme-bound split G-quadruplex probes,
the use of fluorescent dyes eliminates the need for unstable sensing components (H2O2, hemin, and ABTS). Our approach is direct, easy to conduct, and fully compatible with the detection of specific DNA sequences
in biological fluids. Having two different types of probe was highly valuable in the context of applied studies, because Zn-DIGP
was found to be compatible with samples containing both serum and urine whereas NMM was compatible with urine, but not with
serum-containing samples. 相似文献
996.
Zhi-Xian Yu Rong Yuan Cheng-Hsiung Hsu Qin Jiang 《Journal of Differential Equations》2011,251(3):630-650
In this paper, we will establish the existence and nonexistence of traveling waves for nonlinear cellular neural networks with finite or infinite distributed delays. The dynamics of each given cell depends on itself and its nearest m left or l right neighborhood cells where delays exist in self-feedback and left or right neighborhood interactions. Our approach is to use Schauder?s fixed point theorem coupled with upper and lower solutions of the integral equation in a suitable Banach space. Further, we obtain the exponential asymptotic behavior in the negative infinity and the existence of traveling waves for the minimal wave speed by the limiting argument. Our results improve and cover some previous works. 相似文献
997.
We prove a uniqueness theorem in terms of value distribution for meromorphic solutions of a class of nonlinear partial differential equations of first order, which shows that such solutions f are uniquely determined by the zeros and poles of f−cj (counting multiplicities) for two distinct complex numbers c1 and c2. 相似文献
998.
A new method of moving asymptotes for large-scale minimization subject to linear equality constraints is discussed.In this method,linear equality constraints are deleted with null space technique and the descending direction is obtained by solving a convex separable subproblem of moving asymptotes in each iteration. New rules for controlling the asymptotes parameters are designed and the global convergence of the method under some reasonable conditions is established and proved.The numerical results show that the new method may be capable of processing some large scale problems. 相似文献
999.
Empirical likelihood(EL) ratio statistic on θ = g(x) is constructed based on the inverse probability weighted imputation approach in a nonparametric regression model Y = g(x) + ε(x ∈ [0,1]p) with fixed designs and missing responses,which asymptotically has χ12 distribution.This result is used to obtain a EL based confidence interval on θ. 相似文献
1000.
In this work, strongly continuous semigroups of pseudocontractions are studied based on an implicit iterative algorithm. Strong convergence theorems of fixed points are obtained in an arbitrary Banach space. 相似文献