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11.
Mariusz Mamiński 《Analytica chimica acta》2005,540(1):153-157
In this paper we report two simple and sensitive spectrophotometric procedures for the determination of dopamine in microfluidic system based on poly(dimethylsiloxane) (PDMS) technology and comparison of their interference-susceptibility. The analytical reactions and measurements were carried out at ambient temperature in a microreactor of total volume 6 μl coupled with a spectrophotometric flow-through cuvette. 相似文献
12.
Mariusz Urbaniak 《Tetrahedron》2006,62(7):1508-1511
The conditions of a simple synthesis of tetra(alkoxymethyl) derivatives of resorcinarene via the Mannich reaction catalysed with iminodiacetic acid are described. A possibility of high yield synthesis of such derivatives for the selected straight-chain alcohols is shown. A possible mechanism of this reaction is suggested. 相似文献
13.
Guilard R Gryko DT Canard G Barbe JM Koszarna B Brandès S Tasior M 《Organic letters》2002,4(25):4491-4494
[reaction: see text] We have developed a new method that affords regioisomerically pure corroles possessing up to three different substituents at the meso positions. The corrole formation reaction involves the acid-catalyzed condensation of a dipyrromethane-dicarbinol with pyrrole followed by oxidation with DDQ. ABC-Type corroles were synthesized for the first time according to this procedure. 相似文献
14.
Unilamellar vesicles of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and varying quantities of either 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-(1-glycerol) (sodium salt) (DMPG) or 1,2-dimyristoyl-3-trimethylammonium-propane (chloride salt) (DMTAP) were used to deposit lipid bilayer assemblies on self-assembled monolayers (SAMs) on gold. The supporting SAMs in turn were composed of ferrocene-functionalized hexadecanethiol chains (FcC16SH) diluted to low coverage in 1-hydroxylhexadecanethiol (HOC16SH) or a single-component monolayer phase of the latter. The mass coverages of the DMPC/DMPG layers deposited in this way were measured using surface plasmon resonance (SPR) and found to decrease with an increasing content of DMPG in the vesicles. The SPR data show that the lipid assembly, while stable with respect to gentle rinsing in aqueous buffer, is reversible and the lipid adlayer is removable by immersion in a solvent such as ethanol. The effects of the adsorbed lipid layer on the electrochemical interactions of the hybrid lipid/SAM with several redox probes [e.g., K4Fe(CN)6, Ru(NH3)6Cl3, and CsHsFe-[(C5H4CH2N+H(CH3)2] were characterized using cyclic voltammetry (CV). At a composition of 5% DMPG in DMPC, the permeabilities of the probes through the lipid layer were affected significantly relative to that observed with a pure DMPC layer. These effects include a striking observation of an enhanced, ionic-charge-specific molecular discrimination of the electrochemical probes. At higher concentrations of the DMPG, significant permeation of the lipid adlayer was seen for all the probes. These latter changes are also attended by a significant increase in the capacitive currents measured in CV experiments as compared to those observed for either a pure SAM or one modified by only DMPC. This effect likely results from the influence of the charged lipid on the diffuse Gouy-Chapman electrolyte layer at the SAM interface. In contrast to the behaviors seen with DMPG, the incorporation of DMTAP into the adsorbed DMPC had no impact on the permeation of the adlayer by soluble redox probes as judged by the observed electrochemistry, a result that appears to correlate with a less ideal mixing of lipids in the DMPC/DMTAP system relative to that of a DMPC/DMPG mixture. 相似文献
15.
Kaczmarek K Walczak B de Jong S Vandeginste BG 《Journal of chemical information and computer sciences》2002,42(6):1431-1442
Automatic alignment (matching) of two-dimensional gel electrophoresis images is of primary interest in the evolving field of proteomics. In the present study, feature-based matching techniques, in their classical and robust versions, are described, and an automatic method of fuzzy alignment (FA) is introduced. This method allows automatic matching of two gel images with different numbers of features with unknown correspondence. Performance of FA is tested on simulated and real data sets. 相似文献
16.
Mariusz Klobukowski 《Theoretical chemistry accounts》1992,83(3-4):239-248
Summary The effective core potential and model potential methods were used in post-SCF calculations on HC1, HBr, Cl2, and Br2 in order to gain insight into the effect of insufficient representation of inner nodes in the valence orbitals of the approximate methods. The results show that while the correlation energy may be slightly overestimated (by 1–7%), both the electric moment functions and the quantities depending on energy differences are consistently similar for the methods studied and close to the results from all-electron calculations.Dedicated to Prof. Klaus Ruedenberg 相似文献
17.
The complexation of tetramethylresorc[4]arene with primary and secondary amines in acetonitrile was investigated spectrophotometrically. The stoichiometry of the complexes formed was shown to depend on the amine concentration. Based on the proposed complexation models, the formation constants of the complexes as well as their thermodynamical parameters were determined and discussed. Depending on the amine concentration, two types of solid complexes of tetramethylresorc[4]arene with amines were obtained. The composition of these complexes was confirmed by 1H NMR. 相似文献
18.
Kaczmarek P Jezowska-Bojczuk M Gatner K Bal W 《Dalton transactions (Cambridge, England : 2003)》2005,(11):1985-1988
Redox properties of Cu(II) complexes of the terminally blocked hexapeptide -TESHHK- and a series of its alanine substituted analogs: -TASHHK-, -TEAHHK-, -TESAHK-, -TESHAK-, were investigated in their reactions with hydrogen peroxide in solution and by cyclic voltammetry in a broad range of pH. The formation of reactive oxygen species was followed with the use of spectrophotometric indicators, NDMA and NBT. The results indicate that the ability of these complexes to generate hydroxyl-like radicals correlates with the formation of active Cu(III) complexes resulting from the oxidation of Cu(II) by H2O2, which interact with further H2O2 molecules specifically. 相似文献
19.
Ergodicity of a Class of Cocycles Over Irrational Rotations 总被引:1,自引:0,他引:1
It is proved that if is irrational and L2(S1) with o(l/n)then for each mZ\{0} the corresponding skew product
is ergodic. The rigidity of specialflows over irrational rotations with roof functions whose Fouriercoefficients are in o(l/n) is also shown. 相似文献
20.
The relativistic ground and low-lying excited state potential energy curves of AgH and AuH in the presence of a cylindrical
harmonic confining potential were calculated using the multi-state multi-reference perturbation theory with the spin-free
no-pair Hamiltonian obtained via the third-order Douglas–Kroll transformation, incorporated with the full two-electron Breit–Pauli
spin–orbit operator. The spectroscopic parameters were obtained for both the scalar- and quasi-relativistic potentials. The
spin–orbit coupling constants were calculated for several strengths of the confining potential, and the effects of the applied
potential on the coupling constants were analyzed using configuration interaction.
This paper is dedicated to Serafín Fraga—colleague, mentor, and friend. 相似文献