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91.
Olimpo García-Beltrán Bruce K. Cassels Natalia Mena Marco T. Nuñez Osvaldo Yañez Julio Caballero 《Tetrahedron letters》2014
In this Letter we present a new probe, (E)-7-(diethylamino)-2-oxo-2H-chromene-3-carbaldehyde oxime (JB), which can detect Cu2+ ions in HEPES buffer under physiological conditions. Benesi–Hildebrand and Job plots demonstrate that the stoichiometry of the Cu2+ complex formed is 2:1. Possible interference with other analytes was examined, and the decrease of the fluorescence of JB at 510 nm when it reacts with Cu2+ was shown to be highly selective. This probe accumulates in the plasmalemma of human neuroblastoma SH-SY5Y cells. Molecular dynamics (MD) simulations revealed that JB interacts with the lipid bilayer at the level of the glycerol moieties. 相似文献
92.
Nicoleta E. Mircescu Haibo Zhou Nicolae Leopold Vasile Chiş Natalia P. Ivleva Reinhard Niessner Andreas Wieser Christoph Haisch 《Analytical and bioanalytical chemistry》2014,406(13):3051-3058
Based on molecular-specific surface-enhanced Raman scattering (SERS) spectroscopy we were able to discriminate between rough and smooth strains of Escherichia coli and Proteus mirabilis bacteria. For this purpose, bacteria have been immobilized through electrostatic forces by inducing a positive charge on the glass slide. This way, SERS spectra on bacterial biomass and also on single bacteria could be recorded in less than 2 h, by using concentrated silver nanoparticles as SERS-active substrate. Single-bacterium SERS spectral fingerprints showed to be sensitive to the presence of the O-antigen at strain level and to the microorganisms growth phase. By using principal component analysis (PCA) on the SERS spectra recorded from E. coli and P. mirabilis, these two uropathogens could be fairly discriminated. 相似文献
93.
Natalia P. Malikova Ludmila P. Burakova Svetlana V. Markova Eugene S. Vysotski 《Analytical and bioanalytical chemistry》2014,406(23):5715-5726
Calcium ion is a ubiquitous intracellular messenger, performing this function in many eukaryotic cells. To understand calcium regulation mechanisms and how disturbances of these mechanisms are associated with disease states, it is necessary to measure calcium inside cells. Ca2+-regulated photoproteins have been successfully used for this purpose for many years. Here we report the results of comparative studies on the properties of recombinant aequorin from Aequorea victoria, recombinant obelins from Obelia geniculata and Obelia longissima, recombinant mitrocomin from Mitrocoma cellularia, and recombinant clytin from Clytia gregaria as intracellular calcium indicators in a set of identical in vitro and in vivo experiments. Although photoproteins reveal a high degree of identity of amino acid sequences and spatial structures, and, apparently, have a common mechanism for the bioluminescence reaction, they were found to differ in the Ca2+ concentration detection limit, the sensitivity of bioluminescence to Mg2+, and the rates of the rise of the luminescence signal with a sudden change of Ca2+ concentration. In addition, the bioluminescence activities of Chinese hamster ovary cells expressing wild-type photoproteins also differed. The light signals of cells expressing mitrocomin, for example, slightly exceeded the background, suggesting that mitrocomin may be hardly used to detect intracellular Ca2+ without modifications improving its properties. On the basis of experiments on the activation of endogenous P2Y2 receptor in Chinese hamster ovary cells by ATP, we suggest that wild-type aequorin and obelin from O. longissima are more suitable for calcium detection in cytoplasm, whereas clytin and obelin from O. geniculata can be used for calcium measurement in cell compartments with high Ca2+ concentration. Figure
Hydromedusan photoproteins differ in Ca2+ concentration detection limit, sensitivity of bioluminescence to Mg2+, and rates of rise of luminescence signal with a sudden change of [Ca2+] despite a high degree of identity of their amino acid sequences and spatial structures, and, apparently, a common mechanism for the bioluminescence reaction. 相似文献
94.
Maria A. Simonova Elena. E. Petrova Olga A. Dmitrenko Ravilya L. Komaleva Natalia S. Shoshina Larisa V. Samokhvalova Tatiana I. Valyakina Eugene V. Grishin 《Analytical and bioanalytical chemistry》2014,406(25):6447-6452
Detection of staphylococcal toxins presents a great interest for medical diagnostics. Screening of clinical samples for the presence of several types of staphylococcal toxins using traditional methods—biological tests on animals or cell cultures as well as ELISA—is laborious. Multiplex detection methods would simplify testing. We have designed an xMAP-based assay to detect three staphylococcal toxins—enterotoxins A and B (SEA and SEB) and toxic shock syndrome toxin (TSST)—in cultural supernatants obtained from different strains of Staphylococcus aureus. The limits of detection of SEA, SEB, and TSST multiplex detection in S. aureus growth medium were 10, 1,000, and 5 pg/mL, respectively. Fifty-nine samples of S. aureus cultural supernatants were tested with the xMAP assay. The developed assay has proved highly effective detection of the natural toxins in the samples obtained due to bacterial cells cultivation. In prospect, the developed test system can be used in clinical diagnostics and in monitoring of foodstuffs and environmental objects. 相似文献
95.
Natalia G. Petrochko R. Gregory Peters Russell G. Baughman 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(5):508-511
The crystal structures of the title compounds, [Mo{(C4H8NO)2P(C2F5)}(CO)5], (1a), and [Mo{(C5H10N)2P(C2F5)}(CO)5], (2a), were determined as part of a larger project that focuses on the synthesis and coordination chemistry of phosphane ligands possessing moderate (electroneutral, i.e. neither electron‐rich nor electron‐deficient) electronic characteristics. Both complexes feature a slightly distorted octahedral geometry at the metal center, due to the electronic and steric repulsions between two of the four equatorial CO groups and the pentafluoroethyl group attached to the phosphane ligand. Bond length and angle data for (1a) and (2a) support the conclusion that the free phosphane ligands are electroneutral. For complex (1a), the Mo—P, Mo—Cax and Mo—Ceq(ave) bond lengths are 2.5063 (5), 2.018 (2) and 2.048 (2) Å, respectively, and for complex (2a) these values are 2.5274 (5), 2.009 (3) and 2.050 (3) Å, respectively. Geometric data for (1a) and (2a) are compared with similar data reported for analogous Mo(CO)5 complexes. 相似文献
96.
Natalia Chinchaladze 《PAMM》2015,15(1):181-182
The present paper is devoted to the system of degenerate partial differential equations arise from the investigation of elastic two layered prismatic shells. Harmonic vibration of cusped double-layered plates is consider. The weak setting of the BVPs in the case of the zero approximation of hierarchical models is considered. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
97.
Katarzyna Godlewska Pawe Pacyga Izabela Michalak Anita Biesiada Antoni Szumny Natalia Pachura Urszula Piszcz 《Molecules (Basel, Switzerland)》2021,26(7)
Nutraceuticals and functional foods are gaining more attention amongst consumers interested in nutritious food. The consumption of foodstuffs with a high content of phytochemicals has been proven to provide various health benefits. The application of biostimulants is a potential strategy to fortify cultivated plants with beneficial bioactive compounds. Nevertheless, it has not yet been established whether the proposed higher plants (St. John’s wort, giant goldenrod, common dandelion, red clover, nettle, and valerian) are appropriate for the production of potential bio-products enhancing the nutritional value of white cabbage. Therefore, this research examines the impact of botanical extracts on the growth and nutritional quality of cabbage grown under field conditions. Two extraction methods were used for the production of water-based bio-products, namely: ultrasound-assisted extraction and mechanical homogenisation. Bio-products were applied as foliar sprays to evaluate their impact on total yield, dry weight, photosynthetic pigments, polyphenols, antioxidant activity, vitamin C, nitrates, micro- and macroelements, volatile compounds, fatty acids, sterols, and sugars. Botanical extracts showed different effects on the examined parameters. The best results in terms of physiological and biochemical properties of cabbage were obtained for extracts from common dandelion, valerian, nettle, and giant goldenrod. When enriched with nutrients, vegetables can constitute a valuable component of functional food. 相似文献
98.
99.
Egor A. Kapitonov Natalia N. Petrova Vasilii V. Mukhin Leonid A. Nikiforov Vladimir D. Gogolev Ee Le Shim Aitalina A. Okhlopkova Jin-Ho Cho 《Molecules (Basel, Switzerland)》2021,26(4)
The physical and mechanical properties of nitrile–butadiene rubber (NBR) composites with N-cetylpyridinium bromide-carbon black (CPB-CB) were investigated. Addition of 5 parts per hundred rubber (phr) of CPB-CB into NBR improved the tensile strength by 124%, vulcanization rate by 41%, shore hardness by 15%, and decreased the volumetric wear by 7% compared to those of the base rubber-CB composite. 相似文献
100.
D. N. Vtyurina A. N. Romanov K. S. Zaramenskikh M. N. Vasil’eva Z. T. Fattakhova L. A. Trusov P. A. Loiko V. N. Korchak 《Russian Journal of Physical Chemistry B, Focus on Physics》2016,10(2):211-214
The properties of bismuth-containing luminescent materials prepared by impregnating a porous glass with an aqueous solution of bismuth and aluminum salts followed by thermal treatment are studied. The formation of a variety of bismuth-containing centers luminescent in the near infrared range of the spectrum is revealed, one of which is the Bi+ monocation. At high temperatures, along with it, bismuth-containing cluster-type luminescent centers are apparently formed. 相似文献