Publications by authors named "Strelkova T"

High-temperature polymer-electrolyte membrane fuel cells (HT-PEMFCs) are a very important type of fuel cells since they operate at 150-200 °C, making it possible to use hydrogen contaminated with CO. However, the need to improve the stability and other properties of gas-diffusion electrodes still impedes their distribution. Self-supporting anodes based on carbon nanofibers (CNF) are prepared using the electrospinning method from a polyacrylonitrile solution containing zirconium salt, followed by pyrolysis.

View Article and Find Full Text PDF

The implementation of selective catalytic processes with highly active reagents is an attractive strategy that meets the modern principles of sustainable development of chemistry. In the current study, we for the first time describe the method and general principles of Cu(I)-catalyzed allylation of imines with amine adducts of allylic triorganoboranes. Triallylborane is an extremely reactive compound and cannot be used for the catalytic allylation of imines, whereas its amine adducts are ideal substrates for catalysis.

View Article and Find Full Text PDF

Continuing our investigation of catalytic oxo/imido heterometathesis as novel water-free method for C=N bond construction, we report here the application of classical transition metal oxides dispersed on silica (MO/SiO, M=V, Mo, W) as cheap, robust and readily available alternative to the catalysts prepared via Surface Organometallic Chemistry (SOMC). The oxide materials demonstrated activity in heterometathetical imidation of ketones, WO/SiO being the most efficient. We also describe a new well-defined supported W imido complex (≡SiO)W(=NMes)(MePyr) (Mes=2,4,6-MeCH, MePyr=2,5-dimethylpyrrolyl) and characterize it with SOMC protocols, which allowed us to identify the position of W on the oxo/imido heterometathesis activity scale (Mo View Article and Find Full Text PDF

Photochemical properties of symmetrical pyromellitic diimide containing two cymantrenyl fragments at two nitrogen atoms were studied with IR, NMR, UV-vis, ESI-MS, and cyclic voltammetry. It was found that new unstable chelates are formed during photolysis. At the same time, the CO ligand dissociates from two Mn(CO) fragments during photoexcitation, which dramatically changes the electronic and redox properties of the molecule compared to the cymantrene derivative containing one imide fragment.

View Article and Find Full Text PDF

Cyclopentadienyl manganese tricarbonyl (cymantrene) is known to undergo photochemical reactions by releasing one of its CO ligands. Here we present the first example of a photorearrangement of a cymantrenylmethyl fragment, where it retains all its three CO ligands. A tandem experimental and DFT (density functional theory)-based computational investigation allows us to explain this unexpected behavior: the rearrangement, indeed, begins with the release of one CO ligand, but cage effect of the solvent captures this CO molecule, allowing it to rapidly reattach once the rearrangement takes place.

View Article and Find Full Text PDF

The design of molecules with effective anticancer properties constructed from both dually active metal complex and organic fragments is a novel trend in medicinal chemistry. This concept suggests the impact of a drug on several biological targets or the synergistic action of both fragments as a single unit. We propose that the combination of a Pd-metallocomplex fragment and an organic unit can be an interesting model for anticancer drug discovery.

View Article and Find Full Text PDF

Substituted on the benzene ring 4-CF-2-chromenes have been prepared from substituted 2-(trifluoroacetyl)phenols and vinyltriphenylphosphonium chloride according to the Schweizer protocol in moderate to excellent yields. The influence of the type and the position of aromatic ring substituents on yields of 4-CF-2-chromenes have been investigated. It has been shown that 4-CF-2-chromenes are convenient precursors to 4-CF-coumarins.

View Article and Find Full Text PDF

Fungal contamination in stored food grains is a global concern and affects food economics and human and animal health. It is clear that there is a need to develop new technologies with improved performances that are also eco-friendly in nature. Due to the bioactivity of essential oils (EOs) in the vapor phase, their low toxicity for humans, and their biodegradability and antifungal properties, EOs could be a suitable solution.

View Article and Find Full Text PDF

We report the first examples of direct imidation of lactones giving the corresponding cyclic imidates via oxo/imido heterometathesis with N-sulfinylamines catalysed by a well-defined silica-supported Ti imido complex.

View Article and Find Full Text PDF
Article Synopsis
  • The study explores the creation of oligo- and polycyclosiloxanes through polycondensation processes, both under equilibrium and non-equilibrium conditions, with and without the inclusion of montmorillonite (MMT).
  • Techniques like infrared (IR) spectroscopy, Si nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry were utilized to analyze the composition and structures of the synthesized materials.
  • The research also compares the structural differences between polymers produced in the presence of MMT and those formed via anionic polymerization methods.
View Article and Find Full Text PDF

Dimethylamine adducts of triallyl-, triprenyl- and trans-cinnamyl(dipropyl)borane are effective reagents for mild homoallylation of primary amines with aqueous formaldehyde in MeOH without an inert atmosphere. A new concept is proposed for the explanation of the high stability of allylborane-amine adducts in aqueous MeOH.

View Article and Find Full Text PDF

Triallylborane-amines adducts are effective stoichiometric allylating agents in the aminoallylation reaction of carbonyl compounds in methanol. Moreover, copper-catalyzed diastereoselective allylation of Ellman's imine was achieved with triallylborane-methylamine adduct.

View Article and Find Full Text PDF

Detection of ALK rearrangements in patients with non-small cell lung cancer (NSCLC) presents a significant technical challenge due to the existence of multiple translocation partners and break-points. To improve the performance of PCR-based tests, we utilized the combination of 2 assays, i.e.

View Article and Find Full Text PDF

Twenty one DNA repair genes were analyzed in a group of 95 BC patients, who displayed clinical features of hereditary disease predisposition but turned out to be negative for mutations in BRCA1 and BRCA2 entire coding region as well as for founder disease-predisposing alleles in CHEK2, NBN/NBS1 and ATM genes. Full-length sequencing of CHEK2 and NBN/NBS1 failed to identify non-founder mutations. The analysis of TP53 revealed a woman carrying the R282W allele; further testing of additional 108 BC patients characterized by a very young age at onset (35 years or earlier) detected one more carrier of the TP53 germ-line defect.

View Article and Find Full Text PDF

This report presents the initial results of the first Russian molecular epidemiological study of melanoma. The investigation included 1035 patients with stage IIIB-IV melanoma residing in various regions of Russia. Sequencing of BRAF gene revealed mutation in 627 (60.

View Article and Find Full Text PDF

One hundred and ninety-five consecutive surgically treated Russian colorectal cancer (CRC) patients were retrospectively analyzed for the presence of mutations in KRAS, NRAS, BRAF and PIK3CA genes as well as for the microsatellite instability status. Comparison between high-resolution melting analysis, co-amplification at lower denaturation temperature PCR, DNA sequencing and allele-specific PCR for the detection of KRAS codon 12/13 mutations revealed that none of these methods alone provided satisfactory results in 100 % of the analyzed cases; this experience supports the use of more than one mutation-detecting technique at least in some circumstances. KRAS codon 12/13 substitutions were detected in 70 (35.

View Article and Find Full Text PDF

A new modification was designed to determine the activity of N-acetyl-beta-D-hexosaminidase (NAH) in biological fluids. The properties of enzyme molecules to adsorb themselves on chitin at pH 4.5 were made use of within the case study.

View Article and Find Full Text PDF

The paper describes computer-aided processing of video images of mobile biological objects in view of forming tracks and of evaluating their individual kinetic characteristics. The proposed processing procedure allows one avoid lower information quality associated with resultant image contract reduction when combining video frames are summarized and the signal/ratio decreases.

View Article and Find Full Text PDF