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I. I. Anik’ev M. I. Mikhailova E. A. Sushchenko 《International Applied Mechanics》2004,40(12):1405-1410
Empirical formulas for diffraction pressure on the surface of a ball and a cylinder interacting with a weak shock wave are derived based on experimental data.__________Translated from Prikladnaya Mekhanika, Vol. 40, No. 12, pp. 117–123, December 2004. 相似文献
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Egressy-Molnár O Vass A Németh A García-Reyes JF Dernovics M 《Analytical and bioanalytical chemistry》2011,401(1):373-380
Effects of the two most widespread sample preparation techniques on the d,l-enantiomer ratio of extracted selenomethionine were monitored through the analysis of the certified reference material selenium-enriched
yeast and the isolated protein fraction of high selenium monkeypot nut. The extracted selenomethionine (SeMet) fractions were
orthogonally cleaned up with anion exchange chromatography before carrying out the enantiomer-specific detection to increase
the robustness and the efficiency of the subsequent o-phthal-aldehyde and n-isobutyril-cysteine-based derivatisation process and reversed phase-high-performance liquid chromatography-inductively coupled
plasma mass spectroscopy (ICP-MS) detection. The two techniques, namely methanesulphonic acid (MSA) based digestion and proteolytic
digestion with protease XIV, resulted in significantly different ratio of d,l-selenomethionine with the final results of 2.2–2.7% and 0.5–0.6% of d-SeMet, respectively. The study revealed significant differences in the ICP-MS-related sensitivity of the derivatised selenomethionine
enantiomers, which calls attention to the quantification of this selenoamino acid after MSA hydrolysis. 相似文献
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V. S. Gorelik A. A. Anik’ev V. M. Korshunov Yu. P. Voinov A. A. Loboyko 《Physics of Wave Phenomena》2017,25(4):272-275
A technique of probe photoluminescence and Raman spectroscopy has been developed. This technique makes it possible to detect small (10?6 to 10?8 g) amounts of uranyl compounds at short exposure times (1?10 s). The photoluminescence spectra of Na[UO2CH3(COO)3] polycrystals recorded upon excitation by short-wavelength radiation of LEDs and lasers are found to contain equidistant bands with a shift of 854 cm?1, which corresponds to the frequency of totally symmetric uranyl vibration also manifesting itself in Raman spectra. 相似文献
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A novel approach has been developed for phenol detection by combining centri‐voltammetry with bismuth nanoparticles that are used as carrier reagent. The interaction between bismuth and phenol and also the application of centrifugation provide the effective deposition of phenol onto the electrode surface. Direct voltammetric scan without applying any filtration or decantation prevents the analyte loss. As a result, very sensitive results were obtained with linear ranges of 2–75 μM and 100–500 μM and LOD values of 40 nM and 395 nM, respectively. Developed system was also applied for phenol detection in river sample and recovery value was calculated as 115 %. 相似文献
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Using the molecular imprinting approach, we have shown that polyacrylamide-based artificial antibodies against human and bovine hemoglobin have a very high selectivity, as revealed by the free-zone electrophoresis in a revolving capillary. By the same technique we have previously synthesized gel antibodies not only against proteins but also against viruses and bacteria. The synthesis is thus universal, i.e., it has the great advantage of not requiring a modification - or only a slight one - for each particular antigen. The combination synthesis of artificial gel antibodies and electrophoretic analysis reveals small discrepancies in shape and chemical composition not only of proteins, as shown here and in paper Ia, but also of viruses and bacteria, to be illustrated in papers II and III in this series. Upon rehydration, the freeze-dried gel antibodies, selective for human hemoglobin, regain their selectivity. The gel antibodies can repeatedly be used following the removal of the antigen (protein in this study) from the complex gel antibody/antigen by an SDS washing or an enzymatic degradation. 相似文献
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A biosensing system based on α-glucosidase (AG) activity was developed by using bismuth film modified glassy carbon electrode (BiFE). AG enzyme was immobilized on the BiFE by means of gelatin membrane and the activity was measured by the following of liberated 4-nitrophenol from the 4-nitrophenyl-α-d-glucopyranoside (PNPGP) which is the synthetic substrate of the enzyme at the working potential of −950 mV. The proposed system was used as an AG based biosensing system. Experimental data showed that the response current of 4-nitrophenol obtained at the BiFE was linear in concentration range between 0.033 and 0.33 mM of PNPGP. Before examining the analytical characteristics, pH optimization of the AG-biosensor was also performed. Furthermore, the proposed method was applied to analyze two different AG inhibitors (Amaryl and Acorbose) which are important in Noninsulin-dependent diabetes mellitus (NIDDM). 相似文献
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Anikó Nemes Tamás Csóka Szabolcs Béni Zsófia Garádi Dénes Szabó József Rábai 《Helvetica chimica acta》2020,103(8):e2000081
Four new chiral α-(nonafluoro-tert-butoxy)carboxylic acids were synthesized from naturally occurring α-amino acids (alanine, valine, leucine and isoleucine, respectively), and tested in 1H- and 19F-NMR experiments as chiral NMR shift reagents. The NMR studies were carried out at room temperature, using CDCl3 and C6D6 as solvents, and (RS)-α-phenylethylamine and (RS)-α-(1-naphthyl)ethylamine as racemic model compounds. To demonstrate the applicability of the reagents, the racemic drugs ketamine and prasugrel were also tested. 相似文献
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Viktor Sándor Balázs Viktor Berkics Anikó Kilár Béla Kocsis Ferenc Kilár Ágnes Dörnyei 《Electrophoresis》2020,41(13-14):1178-1188
Lipid A represents a heterogeneous group of bacterial outer membrane phosphoglycolipids, which play a major role in the pathogenesis of Gram-negative sepsis. The number and position of phosphoryl and acyl groups in lipid A molecules are key structural determinants in their bioactivities. In this study, a NACE–ESI-MS/MS method was developed for the simultaneous analysis of lipid A isomers possessing a different degree of phosphorylation and acylation. Various C4’- and C1-monophosphorylated lipid A isobars, as well as acylation isomers, were baseline separated within 43 min in a separation medium of methanol/dichloromethane/triethylamine/acetic acid 60:40:1.08:0.36 (v/v/v/v). Both normal and reverse CE polarities could be applied for proper detection of the analytes owing to the combination of a suction effect caused by the nebulizer gas at the outlet end of the capillary and external pressure applied on the inlet vial. The separated lipid A species could be identified unequivocally by their characteristic fragmentation patterns through CID performed in both negative- and positive-ionization modes. The uniqueness of the NACE–ESI-MS/MS method lies in its simplicity and reliability for proving the phosphorylation isomerism (C1 or C4’) and acylation pattern of native lipid A species or those designed for therapeutic applications. 相似文献
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