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81.
Tastet L Schaumlöffel D Bouyssiere B Lobinski R 《Analytical and bioanalytical chemistry》2006,385(5):948-953
A method based on ICP collision-cell MS detection in capillary HPLC was developed to gain an insight into the purity and identity of selenium-containing proteins separated by 1-D and 2-D electrophoresis. The bands and spots obtained after the separation of water-soluble proteins in selenized yeast were digested with trypsin prior to chromatography. Selenium could be detected down to the subpicogram level. The method, assisted by information obtained by MALDI TOF MS on the 5000 Da cut-off fraction, permitted the purity of bands and spots to be estimated and the efficiency of tryptic digestion and the quantity of selenium present in individual peptides to be evaluated. Owing to the high sensitivity and the lack of matrix suppression effects, the method provided chromatograms with signal-to-noise ratios of 10–1000 in conditions where the common ES Q–TOF MS detection failed.
相似文献
82.
Ryszard Kacprzyk 《Journal of Electrostatics》2010,68(2):190-195
A simplified analysis of the charge decay processes for samples equipped with different types of grounding electrodes is presented. It is shown that the electrical properties of the back electrode (injecting or blocking) can strongly influence the charge decay process for plane parallel dielectric samples. The theory is confirmed by experimental investigation. For the sample with blocking back electrode the 50% time decay parameter can be an order of magnitude higher compared to that obtained for injecting or side electrode. In practical situations charge decay with the plane parallel samples may be much slower than that predicted by measurements carried out according to current standards. 相似文献
83.
Pawel Lukaszczuk E. Borowiak-Palen Mark H. Rümmeli Ryszard J. Kalenczuk 《Applied Physics A: Materials Science & Processing》2010,100(2):505-510
In this contribution we present a systematic study on the dispersion of SWCNTs in a water-based solution of biocompatible
detergent: sodium deoxycholate (DOC). By avoiding harsh chemical conditions, which are known to damage nanotubes structure,
a stable SWCNTs suspension was created. Long term stirring of the solution led to preparation of a stable transparent solution,
containing well-dispersed isolated SWCNTs. The as-prepared dispersion remained stable and clear for two months. Optical absorption
spectroscopy was employed to measure SWCNTs suspension stability. Nanotube aggregation was evaluated through the tangential
mode (G mode) present in the Raman spectrum. High-resolution transmission electron microscopy was employed to observe the
mechanism of debundling process. 相似文献
84.
Jerzy Grzybowski Hubert Przybycień Ryszard Urbański 《Set-Valued and Variational Analysis》2013,21(2):201-216
Any abstract convex cone S with a uniformity satisfying the law of cancellation can be embedded in a topological vector space $\widetilde{S}$ (Urbański, Bull Acad Pol Sci, Sér Sci Math Astron Phys 24:709–715, 1976). We introduce a notion of a cone symmetry and decompose in Theorem 2.12 a quotient vector space $\widetilde{S}$ into a topological direct sum of its symmetric subspace $\widetilde{S}_s$ and asymmetric subspace $\widetilde{S}_a$ . In Theorem 2.19 we prove a similar decomposition for a normed space $\widetilde{S}$ . In section 3 we apply decomposition to Minkowski–Rådström–Hörmander (MRH) space with three best known norms and four symmetries. In section 4 we obtain a continuous selection from a MRH space over ?2 to the family of pairs of nonempty compact convex subsets of ?2. 相似文献
85.
Czechowski T Krzyminiewski R Jurga J Chlewicki W 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2008,195(1):52-59
New EPR resonators were developed by using a ceramic material with a high dielectric constant, epsilon=160. The resonators have a high quality factor, Q=10(3), and enhance the sensitivity of an EPR spectrometer up to 170 times. Some advantages of the new ceramic resonators are: (1) cheaper synthesis and simplified fabricating technology; (2) wider temperature range; and (3) ease of use. The ceramic material is produced with a titanate of complex oxides of rare-earth and alkaline metals, and has a perovskite type structure. The resonators were tested with X-band EPR spectrometers with cylindrical (TE(011)) and rectangular (TE(102)) cavities at 300 and 77K. We discovered that EPR signal strength enhancement depends on the dielectric constant of the material, resonator geometry and the size of the sample. Also, an unusual resonant mode was found in the dielectric resonator-metallic cavity structure. In this mode, the directions of microwave magnetic fields of the coupled resonators are opposite and the resonant frequency of the structure is higher than the frequency of empty metallic cavity. 相似文献
86.
We report on the fabrication of two-dimensional polymeric photonic crystal membranes on the surface of silicon using visible-light multibeam interference lithography. The structures are created by the interference of three beams of a green laser. A polymer buffer layer doped with a Rhodamine B laser dye, interlaid between the lithography layer and the silicon substrate, suppresses the effects of strong reflection and nonradiative absorption of silicon on the interference pattern. Large-area defect-free photonic crystal membranes are experimentally realized on silicon surface. 相似文献
87.
We prove that the correlations present in a multipartite quantum state have an operational quantum character even if the state is unentangled, as long as it does not simply encode a multipartite classical probability distribution. Said quantumness is revealed by the new task of local broadcasting, i.e., of locally sharing preestablished correlations, which is feasible if and only if correlations are stricly classical. Our operational approach leads to natural definitions of measures for quantumness of correlations. It also reproduces the standard no-broadcasting theorem as a special case. 相似文献
88.
Ryszard Smarzewski 《Proceedings of the American Mathematical Society》1997,125(5):1391-1397
We give a new characterization of the set of all extreme points of the unit ball in the Banach space of all Lipschitz functions on a metric space This result is applied to get a total variation characterization of in the particular case when is a convex subset of a Banach space.
89.
90.
Bierla K Dernovics M Vacchina V Szpunar J Bertin G Lobinski R 《Analytical and bioanalytical chemistry》2008,390(7):1789-1798
A method was developed for the simultaneous determination of selenomethionine (SeMet) and selenocysteine (SeCys) in meat (chicken
and lamb muscles) and different offal tissues (heart, liver, kidney). The analytical procedure was based on the protein extraction
with urea under reducing conditions (dithiothreitol), derivatization of SeCys and SeMet by carbamidomethylation with iodoacetamide
(IAM) followed by quantitative proteolysis. The mixture of the derivatized Se-amino acids was purified by size-exclusion liquid
chromatography (LC) and analysed by ion-paring reversed-phase HPLC–inductively coupled plasma mass spectroscopy (ICP MS).
The quantification of SeCys and SeMet was carried out by the method of standard additions. 77SeMet was used to control the SeMet derivatization efficiency and recovery. The method was validated by the determination
of the Se mass balance. The Se-amino acids accounted for 91 ± 8% of the total selenium (mean of 95 samples of seven tissues
analysed over a period of 18 months). The method was applied to the discrimination of the contribution of selenoproteins (containing
SeCys) and other Se-containing proteins (containing SeMet) in tissues of animals during supplementation studies (dose–effect
and tolerance). 相似文献