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991.
Alexandr N. Chernov Tatiana A. Filatenkova Ruslan I. Glushakov Alexandra S. Buntovskaya Diana A. Alaverdian Anna N. Tsapieva Alexandr V. Kim Evgeniy V. Fedorov Sofia S. Skliar Marina V. Matsko Elvira S. Galimova Olga V. Shamova 《Molecules (Basel, Switzerland)》2022,27(15)
Glioblastoma (GBM) is one of the most aggressive and lethal malignancy of the central nervous system. Temozolomide is the standard of care for gliomas, frequently results in resistance to drug and tumor recurrence. Therefore, further research is required for the development of effective drugs in order to guarantee specific treatments to succeed. The aim of current study was to investigate the effects of nerve growth factor (NGF), human cathelicidin (LL-37), protegrin-1 (PG-1), and temozolomide on bioenergetic function of mitochondria, clonogenicity, and migration of human U251 glioma cells. Colony formation assay was used to test the ability of the glioma cells to form colonies in vitro. The U251 glioma cells migration was evaluated using wound-healing assay. To study the mitochondrial metabolism in glioma cells we measured oxygen consumption rates (OCR) and extracellular acidification rates (ECAR) using a Seahorse XF cell Mito stress test kit and Seahorse XF cell Glycolysis stress kit, respectively. We revealed that LL-37, NGF, and TMZ show strong anti-tumorigenic activity on GMB. LL-37 (4 μM), TMZ (155 μM), and NGF (7.55 × 10−3 μM) inhibited 43.9%–60.3%, 73.5%–81.3%, 66.2% the clonogenicity of glioma U251 cells for 1–2 days, respectively. LL-37 (4 μM), and NGF (7.55 × 10−3 μM) inhibited the migration of U251 glioma cells on the third and fourth days. TMZ also inhibited the migration of human glioma U251 cells over 1–3 days. In contrast, PG-1 (16 μM) stimulated the migration of U251 glioma cells on the second, fourth, and sixth days. Anti-mitogenic and anti-migration activities of NGF, LL-37, and TMZ maybe are relation to their capacity to reduce the basal OCR, ATP-synthetase, and maximal respiration of mitochondria in human glioma U251 cells. Glycolysis, glycolytic capacity and glycolytic spare in glioma U251 cells haven`t been changed under the effect of NGF, LL-37, PG-1, and TMZ in regard to control level. Thus, LL-37 and NGF inhibit migration and clonogenicity of U251 glioma cells, which may indicate that these compounds have anti-mitogenic and anti-migration effects on human glioma cells. The study of the mechanisms of these effects may contribute in the future to the use of NGF and LL-37 as therapeutic agents for gliomas. 相似文献
992.
Inese Kokina Ilona Plaksenkova Renata Galek Marija Jermaonoka Elena Kirilova Vjaceslavs Gerbreders Marina Krasovska Eriks Sledevskis 《Molecules (Basel, Switzerland)》2021,26(21)
Sustainable agricultural practices are still essential due to soil degradation and crop losses. Recently, the relationship between plants and nanoparticles (NPs) attracted scientists’ attention, especially for applications in agricultural production as nanonutrition. Therefore, the present research was carried out to investigate the effect of Fe3O4 NPs at low concentrations (0, 1, 10, and 20 mg/L) on three genotypes of barley (Hordeum vulgare L.) seedlings grown in hydroponic conditions. Significant increases in seedling growth, enhanced chlorophyll quality and quantity, and two miRNA expression levels were observed. Additionally, increased genotoxicity was observed in seedlings grown with NPs. Generally, Fe3O4 NPs at low concentrations could be successfully used as nanonutrition for increasing barley photosynthetic efficiency with consequently enhanced yield. These results are important for a better understanding of the potential impact of Fe3O4 NPs at low concentrations in agricultural crops and the potential of these NPs as nanonutrition for barley growth and yield enhancement. Future studies are needed to investigate the effect of these NPs on the expression of resistance-related genes and chlorophyll synthesis-related gene expression in treated barley seedlings. 相似文献
993.
994.
Evgueni Barmatov Dmitry Pebalk Marina Barmatova Valery Shibaev 《Macromolecular rapid communications》2000,21(7):369-374
An effective way to synthesize liquid crystalline ionomers by an exchange reaction between the acid groups of functionalized LC polymers and a metal acetate was examined. A number of LC ionomers containing ions of the alkaline metals Na and Rb (1.2–18.3 mol‐%) were obtained. The introduction of small amounts (1.2–5 mol‐%) of metal ions into a functionalized LC polymer matrix leads to significant changes in the phase state of copolymers – the nematic phase is replaced by a SmA phase; an increase of the content of alkaline metal ions causes linear growth of clearing temperatures. The influence of the nature of the metal ions on the phase behavior of LC ionomers was determined. To describe the peculiarities of the LC ionomers' phase behavior a model based on the assumption that an ion multiplet is formed was proposed. Here, the rigidity of the functionalized LC copolymer chains used as a matrix for the preparation of LC ionomers was taken into consideration. 相似文献
995.
Antonio Luis Crego Jesús Martínez María Luisa Marina 《Journal of separation science》2000,23(5):373-378
The effect of some instrumental parameters on column efficiency in open tubular capillary electrochromatography (OTCEC) has been evaluated. First, it was investigated whether band broadening due to the sample injection process is within a tolerable range when an open tubular column (OTC) of about 10 μm i. d. is used. As a result of the small injection profile factor (K2 = 1.3), injected volumes must be sufficiently small (less than 10 pL) to avoid a significant efficiency loss (>5%) when hydrodynamic injection by siphoning is employed. Secondly, the kinetic performance of OTCs in a CEC system was estimated from the variation of the reduced plate height (h) with the reduced linear velocity (ν) which was controlled by the voltage applied. Reasonable agreement was obtained between the theoretical h versus ν curve and the experimental values for a group of polycyclic aromatic hydrocarbons used as test compounds. Values of 0.25 for minimum h at an optimum ν of 16 are estimated, which permit separations with around 400,000 plates per meter to be obtained in less than 5 min. Finally, the possibility of estimating the diffusion coefficients of the solutes in the mobile phase from the plot of the height of a theoretical plate versus electroosmotic flow velocity is shown. 相似文献
996.
Edwige Godlewski Marina Olazabal Pierre-Arnaud Raviart 《Journal de Mathématiques Pures et Appliquées》1999,78(10):1013
In order to investigate the linearized stability or instability of compressible flows, as it occurs for instance in Rayleigh–Taylor or Kelvin–Helmholtz instabilities, we consider the linearization at a material discontinuity of a flow modeled by a multidimensional nonlinear hyperbolic system of conservation laws. Restricting ourselves to the plane-symmetric case, the basic solution is thus a one-dimensional contact discontinuity and the normal modes of pertubations are solutions of the resulting linearized hyperbolic system with discontinuous nonconstant coefficients and source terms. While in Eulerian coordinates, the linearized Cauchy problem has no solution in the class of functions, we prove that for a large class of systems of conservation laws written in Lagrangian coordinates and including the Euler and the ideal M.H.D. systems, there exists a unique function solution of the problem that we construct by the method of characteristics. 相似文献
997.
Mirjana Puharic Slavica Ristic Marina Kutin Zivoslav Adamovic 《Journal of Russian Laser Research》2007,28(6):619-628
Classical methods and the laser-Doppler-anemometry (LDA) application for the test section calibration of a water-cavitation
tunnel is presented. The results show that the LDA is the best method for calibration and the classical methods satisfy the
needs of standard tests. The advantages of the LDA are illustrated by determination of the pressure coefficient C
p
for a hydrofoil of a high-speed axial pump under the stationary and nonstationary conditions, as well. The velocity vector
distribution is measured around the central hydrofoil of a straight grid for angles of attack δ = 0° and 25° and undisturbed
velocity v
∞ = 5.32 m/s. The results of the LDA measurements are used as a basis for the definition of the boundary conditions for numerical
flow simulation and C
p
calculation by the Fluent program. A flow visualization is made by aniline dyes and air bubbles. 相似文献
998.
Marina Grubii Boidar antek Zoran Zori Zrinka oi Ivna Vrana Blaenka Gaparovi Rozelindra o-Rakovac Mirela Ivan
i antek 《Molecules (Basel, Switzerland)》2022,27(4)
Marine microalgae and cyanobacteria are sources of diverse bioactive compounds with potential biotechnological applications in food, feed, nutraceutical, pharmaceutical, cosmetic and biofuel industries. In this study, five microalgae, Nitzschia sp. S5, Nanofrustulum shiloi D1, Picochlorum sp. D3, Tetraselmis sp. Z3 and Tetraselmis sp. C6, and the cyanobacterium Euhalothece sp. C1 were isolated from the Adriatic Sea and characterized regarding their growth kinetics, biomass composition and specific products content (fatty acids, pigments, antioxidants, neutral and polar lipids). The strain Picochlorum sp. D3, showing the highest specific growth rate (0.009 h−1), had biomass productivity of 33.98 ± 0.02 mg L−1 day−1. Proteins were the most abundant macromolecule in the biomass (32.83–57.94%, g g−1). Nanofrustulum shiloi D1 contained significant amounts of neutral lipids (68.36%), while the biomass of Picochlorum sp. D3, Tetraselmis sp. Z3, Tetraselmis sp. C6 and Euhalothece sp. C1 was rich in glycolipids and phospholipids (75%). The lipids of all studied microalgae predominantly contained unsaturated fatty acids. Carotenoids were the most abundant pigments with the highest content of lutein and neoxanthin in representatives of Chlorophyta and fucoxanthin in strains belonging to the Bacillariophyta. All microalgal extracts showed antioxidant activity and antimicrobial activity against Gram-negative E. coli and S. typhimurium and Gram-positive S. aureus. 相似文献
999.
Sven Kirschner Matthew Peters Kang Yuan Marina Uzelac Michael J. Ingleson 《Chemical science》2022,13(9):2661
Despite the general high fluorophilicity of boron, organoboranes such as BEt3 and 3,5-(CF3)2C6H3–BPin are shown herein for the first time, to our knowledge, to be effective (solid to solution) phase-transfer catalysts for the fluorination of certain organohalides with CsF. Significant (up to 30% e.e.) chiral induction during nucleophilic fluorination to form β-fluoroamines using oxazaborolidine (pre)catalysts and CsF also can be achieved. Screening different boranes revealed a correlation between calculated fluoride affinity of the borane and nucleophilic fluorination reactivity, with sufficient fluoride affinity required for boranes to react with CsF and form Cs[fluoroborate] salts, but too high a fluoride affinity leading to fluoroborates that are poor at transferring fluoride to an electrophile. Fluoride affinity is only one component controlling reactivity in this context; effective fluorination also is dependent on the ligation of Cs+ which effects both the phase transfer of CsF and the magnitude of the [Cs⋯F-BR3] interaction and thus the B–F bond strength. Effective ligation of Cs+ (e.g. by [2.2.2]-cryptand) facilitates phase transfer of CsF by the borane but also weakens the Cs⋯F–B interaction which in turn strengthens the B–F bond – thus disfavouring fluoride transfer to an electrophile. Combined, these findings indicate that optimal borane mediated fluorination occurs using robust (to the fluorination conditions) boranes with fluoride affinity of ca. 105 kJ mol−1 (relative to Me3Si+) under conditions where a signficant Cs⋯F–B interaction persists.Simple boranes with the optimal fluoride ion affinity are effective as catalysts for phase transfer nucleophilic fluorination with CsF. 相似文献
1000.
Alexander N. Shikov Veronika A. Shikova Anastasiia O. Whaley Marina A. Burakova Elena V. Flisyuk Andrei K. Whaley Inna I. Terninko Yulia E. Generalova Irina V. Gravel Olga N. Pozharitskaya 《Molecules (Basel, Switzerland)》2022,27(22)
The roots of licorice (Glycyrrhiza glabra L.) have been widely used in traditional and officinal medicines for the treatment of different diseases. Natural deep eutectic solvents (NADES) have become popular for the extraction of active principles from medicinal plants. However, the ability of NADES to co-extract trace elements during the isolation of target active compounds is rarely investigated. The aim of this study was to analyze the content of trace elements in acid-based NADES extracts from the roots of G. glabra and the health risks associated with them. In this study, we have tested for the first time the ability of several acid-based NADES to co-extract glycyrrhizic acid (GA) and trace elements from the roots of G. glabra. GA has been identified as the dominant phytochemical in G. glabra NADES extracts (0.145–0.495 mg/g). Due to the close pKa of lactic acid and GA, the yield of GA in lactic acid-based NADES was higher in comparison with other tested NADES. The yield of GA in NADES3-NADES5 was statistically significant and surpassed the yield of GA in water. The recovery of all elements (except Li) by all tested NADES was low (less than 6%). According to an ANOVA test, the hydrogen bond donor type plays a decisive role in the extraction of elements. A strong positive correlation between the recovery of GA and MPI was noted. The metal pollution index, hazard quotient, hazard index, and chronic daily intake were calculated and suggest that all tested NADES extracts of G. glabra roots were nontoxic and possess no health risk for both ingestion and topical application. 相似文献