A series of 1,2-, 1,4-disubstituted or 1,2,4-trisubstituted anthraquinone-based compounds was designed, synthesized, characterized and biologically evaluated for anticancer efficacy. 2- or 4-arylated ...1-hydroxy-9,10-antraquinones (anthracene-9,10-diones) were prepared by Suzuki-Miyaura cross-coupling reaction of 1-hydroxy-2-bromoanthraquinone, 1-hydroxy-4-iodoanthraquinone or 1-hydroxy-2,4-dibromoanthraquinone with arylboronic acids. The cross-coupling reaction of 2,4-dibromo-9,10-anthraquinone with arylboronic acids provide a convenient approach to 2,4-bis arylated 1-hydroxyanthraquinones with a variety of aryl substituent in the 2 and 4 position. The cytotoxicity of new anthraquinone derivatives was evaluated using the conventional MTT assays. The data revealed that six of the aryl substituted compounds among the entire series
,
,
,
,
,
were comparable potent with the commercially available reference drug doxorubicin on the human glioblastoma cells SNB-19, prostate cancer DU-145 or breast cancer cells MDA-MB-231 and were relatively safe towards human telomerase (h-TERT)immortalized lung fibroblasts cells. The results suggested that the in vitro antitumor activity of synthesized 2-aryl, 4-aryl- and 2,4-diaryl substituted 1-hydroxyanthraquinones depends on the nature of the substituent within the cyclic backbone. Docking interaction of 2-, 4-substituted and 2,4-disubstituted 1-hydroxyanthraquinones indicates intercalative mode of binding of compounds with DNA topoisomerase. The interaction with the DNA of 4-aryl-
,
,
and 4-(furan-3-yl)-
1-hydroxyanthraquinones was experimentally confirmed through a change in electroforetic mobility. Further experiments with 1-hydroxy-4-phenyl-anthraquinone
demonstrated that the compound induced cell cycle arrest at sub-G1 phase in DU-145 cells in the concentration 1.1 μM, which is probably achieved by inducing apoptosis. 4-Arylsubstituted 1-hydroxyanthraquinones
and
induced the enhancement of DNA synthesis on SNB19 cell lines.
The surface layer determines the physical properties of aviation materials and, based on these properties, the calculation of surface energy anisotropy can be implemented. Moreover, the value of the ...surface energy determines the service time and the destruction of aircraft structures surface layer, while the surface layer thickness determines the distance at which this process usually takes place. In this work, a new atomically smooth crystal empirical model is built without considering the surface roughness. This model can be used to theoretically predict the surface energy anisotropy and surface layer thickness of metals and other compounds, in particular the aviation materials. The work shows that the surface layer of an atomically smooth metal, like other compounds, consists of two nanostructured layers: d(I) and d(II). Having sufficient accuracy, the proposed model would allow the prediction of aviation materials performance properties without the need for ultrahigh vacuum or other complicated theoretical methods to analyze the surfaces of nanosystem atomic structures.
This work compares the metabolic profiles of plasma and the cerebrospinal fluid (CSF) of the patients with high-grade (III and IV) gliomas and the conditionally healthy controls using the wide-range ...targeted screening of low molecular metabolites by HPLC-MS/MS. The obtained data were analyzed using robust linear regression with Huber's M-estimates, and a number of metabolites with correlated content in plasma and CSF was identified. The statistical analysis shows a significant correlation of metabolite content in plasma and CSF samples for the majority of metabolites. Several metabolites were shown to have high correlation in the control samples, but not in the glioma patients. This can be due to the specific metabolic processes in the glioma patients or to the damaged integrity of blood-brain barrier. The results of our study may be useful for the understanding of molecular mechanisms underlying the development of gliomas, as well as for the search of potential biomarkers for the minimally invasive diagnostic procedures of gliomas.
An energy approach to the consideration of the state of the surface of metal aircraft parts is proposed. The energy aspects of the processes occurring in parts during manufacture, operation, and ...repair are analyzed. The possibility of estimating the energy state of the surface of metal parts by the contact potential difference method is shown.
This article is devoted to improvement of a nondestructive control of metal machine parts by the contact potential difference method. The results of experimental studies of the effect of ...environmental parameters on the contact potential difference measurements with a Kelvin probe on the surface of metal samples from Al, Ti, and Ni are presented. The measured dependence of the contact potential difference on the surface of metals on the environmental parameters has been explained. Practical recommendations for measuring the contact potential difference on the surface of parts have been given. The results can be used in production, operation, and repair of metal machine parts.
The selection of the necessary and sufficient number of Duralumin samples in determining the surface energy of metal aviation components is considered. The surface energy is determined by measuring ...the contact potential difference, which depends on the electron work function for the samples. The number of samples for measuring the contact potential difference must be no less than five.
High-entropy ZrTiCrNiCu coating Yurov, V M; Guchenko, S A; Goncharenko, V I ...
Journal of physics. Conference series,
11/2021, Letnik:
2064, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
A magnetron target made of a high-entropy ZrTiCrNiCu alloy was synthesized by mechanical alloying methods followed by annealing in a vacuum furnace. Using this target, coatings were applied ...to steel samples with a thickness of 7-10 microns. After thermal annealing, the coatings were nanostructured. In terms of microhardness, the ZrTiCrNiCu coating is not inferior to, and in most cases exceeds the hardness of high-entropy equiatomic alloys. A high entropy coating has a low coefficient of friction. They turn out to be anti-friction, which, most likely, leads to energy savings. In this work, the surface energy, contact potential difference and work function of electrons for high-entropy coatings were determined for the first time.
Abstract
The paper establishes the nature of the redistribution of chemical elements and their concentration in secondary surface structures for the material systems “steel ...45XN2MFA-grease-BrOTsS4-4-2.5”, “steel 45XN2MFA-grease-BrOTsS4-4-4”, “steel 45XN2MFA-grease-L-63 ”, tested under the conditions of simulating film starvation when lubricated with 15W40 Lukoil-Super SAE SG/CD engine oil. Since the formula obtained by us includes the Gibbs energy, the self-organization of the structure under consideration naturally also enters. General laws of self-organization are observed when a number of conditions are met: irreversibility, openness (nonequilibrium), nonlinearity, instability (coherence), dissipativity. All these elements were observed and described by us in this work. It is due to self-organization that the distribution of chemical elements carbon and oxygen occurred on the surfaces L63 and BrOF4-4-4. To this effect must be added a decrease in the surface tension of the lubricant.
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