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71.
High-flow pneumatically assisted electrospray ionization mass spectrometry (ESI-MS) has been extensively used for the characterization and determination of peptides and peptide hormones available for biomedical research and therapeutic applications. The aim of this study was to optimize a method of characterization and determination of a mixture of peptide hormones with therapeutic interest by liquid chromatography (LC) coupled to ESI-MS. In this work the linear solvation energy relationship methodology was used in order to optimize the mobile phase to be used in the LC separation of the peptide hormone series and the operational parameters of the source and analyzer of ESI were also optimized to obtain the best signal stability and the highest sensitivity. To validate the proposed method for peptide hormone analysis, quality parameters were determined and satisfactory results were obtained. Likewise, the method detection limit was picomole level for most of the peptides employing selected-ion monitoring of the [M+nH]n+ ions. 相似文献
72.
We generalize the Krein-Milman theorem to the setting of matrix convex sets of Effros-Winkler, extending the work of Farenick-Morenz on compact C-convex sets of complex matrices and the matrix state spaces of C-algebras. An essential ingredient is to prove the non-commutative analogue of the fact that a compact convex set may be thought of as the state space of the space of continuous affine functions on .
73.
The impact of individual collision processes on the relaxation of the velocity distribution function of a group of electrons, initially localized in a narrow region at relatively high energies, has been studied. By having recourse to solutions of the non-stationary Boltzmann equation and to corresponding Monte-Carlo simulations, the temporal behaviour of electrons in CO2 plasmas, both in the absence and the presence of an external dc field, has been investigated. A microphysical interpretation of observed relaxation phenomena, based on the data relevant to the individual collision processes, is also given. 相似文献
74.
75.
We show that the fixed point property is comparability invariant for finite ordered sets; that is, if P and Q are finite ordered sets with isomorphic comparability graphs, then P has the fixed point property if and only if Q does. In the process we give a characterization of comparability invariants which can also be used to give shorter proofs of some known results. 相似文献
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Ohne Zusammenfassung 相似文献
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79.
From 1H- and 13C-NMR. data, a crown conformation with trans amide bonds is deduced for 1,6-diaza-2,7-cyclodecadione ( 1 ) in solution. Compound 1 was obtained by reaction of 2-pyrrolidone with POCl3. 相似文献
80.
Collision Dominated Relaxation of the Electron Ensemble in a Plasma with Additional Heating by an Electric Field. III. The Periodic Behaviour of the Electron Component in an Electric Field with a Large Modulation Amplitude With the aid of the non-stationary Boltzmann-equation the periodic behaviour of the isotropic part of the velocity distribution of electrons and thereby determined macroscopic quantities is calculated for periodic electric fields with large modulation amplitude. The investigations concern a weakly ionized column plasma in neon under typical low and medium pressure conditions. Based on the numerical results for typical ranges of field strength and cycle times of the electric field a qualitative physical interpretation for the periodic behaviour of the electron component is obtained. The introduction of special field-dependent adjustment times allows the formalution of conditions which characterize the case of quasi-stationary behaviour and also the case of small amplitudes of modulation in the macroscopic quantities determined by the isotropic distribution function. The periodic states between these two limiting cases can be interpreted as due to two competing processes. The first one is the energy input controlled by the electric field and the second one is the energy loss in binary collisions of the electrons with the atoms. 相似文献