A structural-functional diagram of a dynamic model of a mechatronic system with a planetary hydraulic motor is proposed. The initial conditions for the simulation of transients occurring in a ...mechatronic system with a planetary hydraulic motor are substantiated. The design parameters of the distribution system, which determine the unevenness of the output characteristics of the planetary hydraulic motor, are also substantiated. The influence of the design features of a serial and modernized hydraulic motors on the dynamic processes of the mechatronic system is investigated. It is established that fluctuations in the flow area of the distribution system of a serial hydraulic motor cause pulsations of torque on the hydraulic motor shaft and pressure in the discharge line of the mechatronic system. At the time of acceleration, significant pulsations of the flow of working fluid through the safety valve are observed, and as a result, pulsations of the flow of working fluid through the hydraulic motor. Elimination of fluctuations in the flow area of the distribution system of the upgraded hydraulic motor allows you to stabilize the values of pressure, torque and flow rate of the working fluid throughout the study of the acceleration process. Under steady-state operation, fluctuations in the area of the passage section of the distribution system do not affect the nature of the change in the shaft speed, either of the modernized or serial hydraulic motors.
Herein, we report the design and synthesis of novel 7-aza-coumarine-3-carboxamides via scaffold-hopping strategy and evaluation of their in vitro anticancer activity. Additionally, the improved ...non-catalytic synthesis of 7-azacoumarin-3-carboxylic acid is reported, which features water as the reaction medium and provides a convenient alternative to the known methods. The anticancer activity of the most potent 7-aza-coumarine-3-carboxamides against the HuTu 80 cell line is equal to that of reference Doxorubicin, while the selectivity towards the normal cell line is 9-14 fold higher.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
One of the main stages of research related to increasing the efficiency of planetary hydraulic motors operating as part of the mechatronic systems of self-propelled vehicles is the experimental ...research of real samples. Experimental studies of the influence of design features of the rotor system of serial and modernized hydraulic motors on the output characteristics of mechatronic systems were carried out by means of comparative bench tests. A technique has been developed for conducting comparative bench studies of planetary hydraulic motors. A test bench scheme is proposed for testing a family of unified series of high-torque, low-speed planetary-type hydraulic motors. The main factors determining the change in the output characteristics of the planetary hydraulic motor, taking into account the design features of the rotor system, are: pressure drop, flow rate of the working fluid and the error the manufacturing form of the gear profile of its rotors. Tests of planetary hydraulic motors with a serial and modernized rotor systems were carried out. The modernization of the rotor system was carried out by changing the design of the external and internal rotors in order to reduce the shape error of their gear profile. As a result of experimental studies, it was found that eliminating the error the manufacturing form of the rotors of the modernized hydraulic motor can significantly improve its output characteristics - increase the torque at specified rotation speeds, and as a result, increase the hydromechanical and overall efficiency of the mechatronic system as a whole.
Carbon nanotubes are among the most widely used nanosystems, and stability of carbon nanotube suspensions is critical for nanotechnology and environmental science. Remaining in aqueous environment ...alone misses important factors that regulate colloidal stability in the presence of electrolytes. Indeed, introduction of (80–95) vol % organic solvents leads to sharp changes in suspension properties depending on the solvent. For example, the critical coagulation concentrations for a given inorganic or organic coagulating ion can change by 2 orders of magnitude when going from dimethyl sulfoxide to acetonitrile. We establish and explain these trends by Lewis acid–base interactions and show that a strong interaction extending beyond the standard theory of aggregation plays an important role.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
A series of new 2-hydroxy-3-methoxybenzylidenethiazolo3,2-
pyrimidines with different aryl substituents at the 5 position are synthesized and characterized by
H/
C NMR and IR-spectroscopy and ...mass-spectrometry, as well as single crystal X-ray diffraction (SCXRD). It was demonstrated that the type of hydrogen bonding can play a key role in the chiral discrimination of these compounds in the crystalline phase. The hydrogen bond of the O-H...N type leads to 1D supramolecular heterochiral chains or conglomerate crystallization in the case of the formation of homochiral chains. The hydrogen bond of O-H...O type gave racemic dimers, which are packed into 2D supramolecular layers with a parallel or angular dimers arrangement. Halogen bonding of the N...Br or O...Br type brings a new motif into supramolecular self-assembly in the crystalline phase: the formation of 1D supramolecular homochiral chains instead 2D supramolecular layers. The study of cytotoxicity against various tumor cells in vitro was carried out. It was found that 2-hydroxy-3-methoxybenzylidenethiazolo3,2-
pyrimidines with 3-nitrophenyl substituent at C5 carbon atom demonstrated a high efficiency against M-HeLa (cervical adenocarcinoma) and low cytotoxicity against normal liver cells.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Herein we present the regio- and diastereoselective synthesis of novel pyrrolidine-fused spiro-dihydrophosphacoumarins via intermolecular 3 + 2 cycloaddition reaction. The presented approach is ...complementary to existing ones and provides an easy entry to the otherwise inaccessible derivatives. Additionally, the unprecedented pathway of the reaction of 4-hydroxycoumarin with azomethine ylides is described. The anti-cancer activity of the obtained compounds was tested in vitro, the most potent compound being 2.6-fold more active against the HuTu 80 cell line than the reference 5-fluorouracil, with a selectivity index > 32.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Display omitted
•Push-pull dyes are temperature-sensitive luminophores in dichloromethane solutions.•Hydrophobicity-driven incorporation of the dyes into phospholipid-based bilayers.•Temperature ...sensitive emission of the dyes within phospholipid-bilayers.•Optimal dye for high temperature sensitivity and reversibility under heating/cooling.•The dye within bilayers efficiently stains the cell cytoplasm with low cytotoxicity.
A series of dialkylaminostyrylhetarene dyes constructed from electron-rich and electron-deficient moieties of various structures connected via vinylene π-bridges are introduced as temperature-sensitive luminophores. The temperature dependent emission of the dyes in the acidified dichloromethane solutions derives from temperature-induced shift of the equilibrium between neutral and protonated forms of the dyes. The heating-induced blue shift and intensification of emission of neutral form of the dyes make them a promising basis for development of nanoparticles exhibiting temperature-sensitivity in aqueous solutions at pH typical of biological liquids. Hydrophobicity-driven incorporation of the water insoluble dyes into L-α-phosphatidylcholine(PC)-based bilayers allows to obtain water dispersible dye-PC aggregates, and to follow their emission in the aqueous solutions. Structure of the dyes has strong impact on the efficacy of the dyes incorporation into the PC-based bilayers, temperature sensitivity of emission of the dye-PC aggregates and its reversibility under the heating/cooling cycles. This enables structural optimization of the dyes in order to obtain the dye-PC species demonstrating maximal temperature dependence and reversibility of their luminescence in aqueous solutions. The selected leader exhibits low cytotoxicity exemplified for M−HeLa and Chang Liver cell lines, while the efficient cell internalization of the dye, manifested in the staining of the cell cytoplasm, opens further opportunities for biosensing applications.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this work, we describe the synthesis, interactions with bovine serum albumin, and cytotoxicity of new ionic liquids based on 5-fluorouracil (API-ILs) with different cations (imidazolium, choline, ...isoquinolinium, guanidinium). The secondary and tertiary structure of BSA in solutions with different concentrations of API-ILs was monitored by the circular dichroism (CD) technique. The addition of API-ILs does not lead to structural changes in BSA. A quenching of fluorescence spectra intensity of BSA in presence of all API-ILs was observed, allowing the quantification of binding between API-ILs and BSA. The preferred localization of both ions in API-ILs differs significantly depending on the structure of the cation according to molecular docking. The aggregation of BSA in presence of API-ILs was analyzed by the dynamic light scattering (DLS) method, revealing a moderate increase in particle size. Cytotoxicity and selectivity of API-ILs on cancer and normal cell lines were estimated, showing a clear modification of the pharmaceutic activity of ionic liquid compared to 5-fluorouracil.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Ce, Pr, and La-doped gadolinium pyrosilicate Gd2Si2O7 (GPS) single crystals were grown by the Czochralski and Top Seeded Solution Growth (TSSG) techniques for the first time. Formation conditions of ...different pyrosilicate phases were determined. X-ray luminescence integral intensity of Ce-doped GPS is about one order of magnitude higher in comparison with gadolinium oxyorthosilicate Gd2SiO5:Ce (GSO:Ce). All samples demonstrate temperature stability of luminescence yield up to 400K.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
—
The effect of the content of titanium ions in the crystals of titanium-doped sapphire (Ti:sapphire, up to 0.2 wt % Ti) on the rate of material removal and surface roughness at different stages of ...its processing was studied. It was established that the efficiency of material removal increases with an increase in the density of dislocations in the crystal. It was detected that with an increase in the content of titanium in Ti:sapphire during grinding with a fixed abrasive, the rate of material removal decreases, while in the case of grinding and polishing with a free abrasive, it increases due to a disordering of the crystal structure and deterioration of structural perfection of the crystals. Doping of sapphire with titanium leads to a decrease in the value of the crystal surface roughness parameter at a grinding stage.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PDF
