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排序方式: 共有555条查询结果,搜索用时 15 毫秒
1.
Juraj Bunta Martin Dahlberg Leif Eriksson Nikolai Korolev Aatto Laaksonen Raimo Lohikoski Alexander Lyubartsev Miroslav Pinak Patric Schyman 《International journal of quantum chemistry》2007,107(2):279-291
This work highlights four different topics in modeling of DNA: (i) the importance of water and ions together with the structure and function of DNA; the hydration structure around the ions appears to be the determining factor in the ion coordination to DNA, as demonstrated in the results of our MD simulations; (ii) how MD simulations can be used to simulate single molecule manipulation experiments as a complement to reveal the structural dynamics of the studied biomolecules; (iii) how damaged DNA can be studied in computer simulations; and (iv) how repair of damaged DNA can be studied theoretically. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
2.
The effect of several experimental parameters on enantiomeric separations in micellar capillary electrophoresis (MCE) was studied. A model separation system was tested. It was composed of an acidic phosphate buffer with sodium dodecyl sulfate (SDS) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as the chiral selector. A substituted angelicin was used as a chiral analyte. Changes in the concentration of SDS micelles/SDS monomers in the presence of HP-beta-CD and their impact on the enantioselective separation were investigated. Variation of the composition of electrolytes in the individual compartments of the separation system (inlet vial, capillary, and outlet vial) affected both the migration times and the resolution of the enantiomers. Current vs. time dependencies also were monitored during the separations. A mathematical model of electromigration in micellar systems with chiral selector present was proposed and a computer simulation was used to explain the observed phenomena and to confirm the generation of a CD/SDS-micelle concentration gradient under certain experimental conditions. This is the reported first attempt of a computer simulation of the complex, dynamic chiral environment of the CD-SDS-MCE system. 相似文献
3.
Juraj Pavlinec Eberhard Borsig 《Journal of polymer science. Part A, Polymer chemistry》1981,19(9):2305-2312
A study was made of the methyl methacrylate (MMA) solution polymerization in CCl4-pyridine mixtures as well as in net components at 30, 50, and 70°C. The results obtained show that there are no significant deviations from additivity in the overall chain transfer constants that fit the straight line between the values of Cs for CCl4 and pyridine. It can be concluded that the EDA interaction between CCl4 and pyridine does not change the sensitivity of each component for chain transfer from propagation PMMA free radical. The pyridine in the system increases the rate of MMA polymerization as a result of the higher rate of initiation. 相似文献
4.
The formation of a so-called water/oil (W/O)-microemulsion (AOT/isooctane/water) was followed by light scattering and ultracentrifuge measurements. With increasing weighed-in water concentrations the microemulsion is stabilized by repeated aggregational processes of micelles containing water due to a decrease of the free interfacial enthalpy. This process conforms very satisfactorily to a model describing an adsorption of surfactants at the water/hydrocarbon interface resulting from dipole-image dipole interactions. 相似文献
5.
Jablonsk Josef ern Michal Pekr Juraj 《Central European Journal of Operations Research》2022,30(2):435-447
Central European Journal of Operations Research - The paper discusses operations research (OR) history and achievements in Czechia and Slovakia in 2010–2021 including the most significant OR... 相似文献
6.
7.
R. Ficarra M. L. Calabrò S. Tommasini D. Costantino M. Carulli S. Melardi M. R. Di Bella F. Casuscelli R. Romeo P. Ficarra 《Chromatographia》1996,43(7-8):365-368
Summary A high-performance liquid chromatographic method is reported for the resolution of the enantiomers of a series of fused -lactams (2,7-diaza-3-oxo[3.3.0]octan-6-ones) with probable anti-HIV and anticancer activity. Resolution was achieved on a Chiralcel® OD column, cellulose tris-(3,5-dimethylphenyl carbamate) adsorbed on macroporous silica gel; mixtures ofn-hexane and isopropyl alcohol in different proportions were used as the mobile phase. The analysis was studied at different temperatures. 相似文献
8.
Nemukhin AV Grigorenko BL Khriachtchev L Tanskanen H Pettersson M Räsänen M 《Journal of the American Chemical Society》2002,124(36):10706-10711
Theoretical and matrix-isolation studies of intermolecular complexes of HXeOH with water molecules are presented. The structures and possible decomposition routes of the HXeOH-(H(2)O)(n)(n = 0, 1, 2, 3) complexes are analyzed theoretically. It is concluded that the decay of these metastable species may proceed through the bent transition states (TSs), leading to the global minima on the respective potential energy surfaces, Xe + (H(2)O)(n+1). The respective barrier heights are 39.6, 26.6, 11.2, and 0.4 kcal/mol for n = 0, 1, 2, and 3. HXeOH in larger water clusters is computationally unstable with respect to the bending coordinate, representing the destabilization effect. Another decomposition channel of HXeOH-(H(2)O)(n), via a linear TS, leads to a direct break of the H-Xe bond of HXeOH. In this case, the attached water molecules stabilize HXeOH by strengthening the H-Xe bond. Due to the stabilization, a large blue shift of the H-Xe stretching mode upon complexation of HXeOH with water molecules is featured in calculations. On the basis of this computational result, the IR absorption bands at 1681 and 1742 cm(-1) observed after UV photolysis and annealing of multimeric H(2)O/Xe matrixes are assigned to the HXeOH-H(2)O and HXeOH-(H(2)O)(2) complexes. These bands are blue-shifted by 103 and 164 cm(-1) from the known monomeric HXeOH absorption. 相似文献
9.
Maria A Girault JP Saatov Z Harmatha J Dinan L Lafont R 《Journal of chromatographic science》2005,43(3):149-157
Ecdysteroid glycosides are found in both animals and plants. The chromatographic behavior of these molecules is characteristic, as they appear much more polar than their corresponding free aglycones when analyzed by normal-phase high-performance liquid chromatography (HPLC), whereas the presence of glycosidic moieties has a very limited (if any) impact on polarity when using reversed-phase HPLC. Biological activity is greatly reduced because the presence of this bulky substituent probably impairs the interaction with ecdysteroid receptor(s). 2-Deoxy-20-hydroxyecdysone 22-O-beta-D-glucopyranoside, which has been isolated from the dried aerial parts of Silene nutans (Caryophyllaceae), is used as a model compound to describe the rationale of ecdysteroid glycoside purification and identification. 相似文献
10.
Jozef Chomič Ján Skoršepa Juraj Černák Alexander Hudák 《Monatshefte für Chemie / Chemical Monthly》1982,113(6-7):713-714
The preparation, identification and some properties of three new clathrate compounds Cd(mea)[Pd(CN)4] · 2C6H6, Cd(mea)2[Pd(CN)4] · C4H4S and Cd(mea)2[Pd(CN)4] · C4H4NH (mea = HO-CH2-CH2-NH2) are described. 相似文献