Fluorides are thought to be a major cause of osteocarcinogenesis, due to their widespread industrial use, ability to accumulate in bone tissue, and genotoxic and probable carcinogenic properties. In ...vitro experiments investigating the genotoxic potential of fluorides in bone tissue models can provide valuable indirect information on their involvement in osteocarcinogenesis. Here, we investigated whether sodium fluoride (NaF) has the ability to induce DNA damage and chromosomal abnormalities in human osteosarcoma cells after 48 and 72 h of exposure. The cell cultures were treated with NaF in concentrations of 0, 20, 100 and 200 μg/ml. The level of DNA damage was assessed by the comet assay, and the frequency of chromosomal abnormalities by a micronucleus test. A significant increase in DNA damage indicators was noted in the samples treated with fluoride concentrations of 100 and 200 µg/ml, after 48 and 72 h of exposure. The micronucleus test revealed a dose-dependent increase in cells with micronuclei, nucleoplasmic bridges and nuclear protrusions. Increasing the concentration of NaF led to an increase in the prevalence of cytogenetic indicators after both treatment durations. This demonstrated ability of fluorine to exert genotoxic effects on bone cells indirectly indicates the possible importance of fluoride in the aetiology of osteosarcoma.
We studied the effect of nitinol, the most prevalent material for endovascular stents, on metabolic and coagulation activity of a primary culture of human umbilical vein endothelial cells (HUVEC). ...Metabolic activity was evaluated using MTS-test and by the level of stable NO metabolites in the conditioned medium, coagulation activity was assessed by activity of von Willebrand factor (vWF) and levels of plasminogen activator inhibitor-1 (PAI-1) and soluble endothelial protein C receptors (sEPCR). Exposure to nitinol reduced metabolic activity of the cell culture by 11.1% in comparison with the control (
p
<0.001). Although absolute activity of vWF and absolute level of sEPCR were elevated, incubation with nitinol did not lead to a statistically significant elevation of these parameters in comparison with the control, which can indicate the absence of substantial hypercoagulation effects of nitinol.
The content of the soluble form of protein of the key point of immunity B7-H3 (sB7-H3) in the blood plasma of 75 patients with epithelial ovarian cancer before treatment was measured by ELISA. It is ...known that B7-H3 belongs to the immunoglobulin superfamily (B7 molecule family) and is involved in the regulation of the immune response mediated by T cells. The sB7-H3 concentration correlated with the clinical and morphological parameters of ovarian cancer. The content of sB7-H3 was higher at the later stages of the disease, in the presence of ascites, and in patients with poorly differentiated ovarian cancer. It was revealed that increased plasma content of sB7-H3 in patients with epithelial ovarian cancer is associated with unfavorable prognosis of the disease. Therefore, sB7-H3 can be used as a prognostic marker in ovarian cancer patients.
A spark plasma sintering technology has already become rather common for the fabrication of GexSi1-x nanostructured thermoelectric solid solutions. Such trend is related with a number of ...opportunities and technological tools that enable precise properties manipulation. The present paper is devoted to discussing the modulation of GexSi1-x spark plasma sintering technique that consists in the use of silicon phosphide as a source of n-type doping within the process of sintering. The composition of the sintered powder is investigated. The synthesis of a solid solution was carried out in the process of sintering. The SiP is a chemically stable non-toxic compound that can replace toxic phosphorus in thermoelectric technology thus reducing the safety requirements of the corresponding technology process. The paper investigates the effect of SiP concentration on thermoelectric characteristics. The impurity distribution is analyzed, and the association of phosphorus atoms into clusters at a very high doping level is shown. The distribution of impurity elements was controlled by EMF analysis in a scanning electron microscope. It was shown that sintering of Ge-Si-SiP powder mixture allowed obtaining the phosphorus doped GexSi1-x material with high electron concentration that demonstrate high level of thermoelectric properties. The obtained thermoelectric characteristics are compared with the world's best nanostructured materials
A review of studies on the determination of heparin in various samples (pharmaceuticals, biological fluids) by electrochemical methods of analysis in 1976–2014 is presented. Heparin is most often ...determined in pharmaceuticals by polarography using cationic dyes, and in biological samples, by differential pulse methods on non-stationary mercury electrodes. Works on the creation of heparin-selective electrodes coated with a polyvinylchloride membrane with quarternary ammonium salts are most promising; they can, probably, be used for the creation of portable devices for the determination of heparin.
Abstract
In today’s world diseases of alimentary etiology are common. They occur when there is insufficient intake of important essential substances, that include amino acids. Lack of essential amino ...acids can lead to serious disruptions in vital functions of body. Therefore, development of food products, balanced in amino acid composition, is the most important technological task of food production. Semi-finished products are one of the food groups, that in great demand among the general population. Therefore, these foods are often enriched with disease-preventing nutrients. In addition, creation of products with specified properties allows to reduce cost price due to introducing cheap plant materials into the product. The article provides data on effect of milk thistle powder and flaxseed flour on amino acid composition of meat stuffed chopped semi-finished products. Calculation of parameters of amino acid score and amino acid index in the products is presented. The results of organoleptic evaluation of experimental samples are also presented. During the study, mass fractions of proteins, fats and carbohydrates were determined. Organoleptic evaluation was carried out and energy value of each sample was calculated. Based on obtained data, a comparison was made between control sample and experimental samples in all parameters. In addition, it was found that a test sample containing milk thistle powder is capable of increasing protein content, as well as increasing amino acid index and amino acid score of the product.
Samples of the initial composition Mg
1 –
x
Ni
x
Ga
2
O
4
(0 ≤
х
≤ 1, step
х
= 0.1) synthesized by the gel combustion method and annealed at 1000°C have been studied by X-ray powder diffraction and ...IR spectroscopy. For homogeneous samples of (Mg,Ni)Ga
2
O
4
with a spinel structure, the gallium nonstoichiometry has been determined by inductively coupled plasma atomic emission spectrometry. Within the framework of the MgO–NiO–Ga
2
O
3
system, the boundary of the homogeneity region of spinel (Mg,Ni)Ga
2
O
4
, which is in equilibrium with halite (Mg,Ni)O, has been outlined. An analysis of the diffuse reflectance spectra of (Mg,Ni)Ga
2
O
4
in the range of 350–900 nm revealed intense absorption bands from Ni
2+
in octahedral positions and showed an increase in their intensity with an increase in the nickel content in the spinel.
New recombinant strains of
Penicillium verruculosum
with a high level of expression of homologous
endo
-β-1,4-glucanase II and heterologous phytase A of
A. niger
, as well as heterologous
endo
...-1,4-β-xylanase E of
P. canescens
and phytase A of
A. niger
, are created. This allows us to obtain highly active feed enzyme preparations (EPs) capable of simultaneously significantly reducing the viscosity of nonstarch polysaccharides (NPSs), as well as increasing the bioavailability of phosphorus and minerals of grain-based feed and, thus, increasing the digestibility of nutrients of agricultural animal and poultry feed. Specific EP activities for specific substrates (xylan, β-glucan, and phytate) are studied and the qualitative and quantitative component composition of new EPs is determined. A recipient strain δnia D, into which heterologous
endo
-1,4-β-xylanase E of
P. canescens
is successfully cloned, is obtained based on a new enzyme preparation containing homologous
endo
-β-1,4-glucanase II and heterologous phytase A of
A. niger.
In this way, a promising producer of three target enzymes is obtained simultaneously.
The boundaries of Mg
1 –
x
Ni
x
Ga
2
O
4
solid solutions (0 ≤
х
≤ 0.5) with a spinel structure synthesized by the gel combustion method, annealed at 1000°C, and furnace cooled have been ...experimentally determined for the first time. Mg
1 –
x
Ni
x
Ga
2
O
4
samples (0 ≤
х
≤ 1, step
х
= 0.1) with an inverse spinel structure have been studied by X-ray diffraction and IR spectroscopy. It has been found that the range of the (Mg,Ni)Ga
2
O
4
solid solution can deviate from the line connecting the stoichiometric compositions MgGa
2
O
4
and NiGa
2
O
4
. The diffuse reflectance spectra of Mg
0.9
Ni
0.1
Ga
2
O
4
and Mg
0.5
Ni
0.5
Ga
2
O
4
spinels show an intense absorption band corresponding to Ni
2+
in the near-IR range, which is of great interest for using this property in laser and optoelectronic technologies with minimal negative impact on the environment.
Introduction. The use of modifying nano-additives in the production of binding building materials is one of the most effective ways to control the technological parameters of concrete by conducting ...good control of the rheological characteristics reliability. Plasticizing additives increase the water-holding capacity of building compositions, which leads to the dispersed nanosystems stability. This article is focused on examining the physical and chemical mechanisms of the supramolecular effects of polycarboxylate ethers on technological and rheological characteristics of cement nanobinders. Methods and materials. This study describes controlled hardening processes of concrete nanocompositions with demanded technological characteristics in the presence of highly effective plasticizers. Moreover, this paper carries out the analysis of the innovative trends in regulating the consistency of building nanocomposites with the use of new comb-like polycarboxylate esters, which as superplasticizers allow to purposefully influence the kinetics of structure formation of cement nanocomposites. Results. Electrostatic and steric repulsion mechanisms, as well as the dispersing effects of innovative and traditional plasticizing nanoparticles, affect the adsorption and diffusion layers of the hydrated cement nanobinders ultrastructure. The most effective plasticizing properties are shown by comb-like polycarboxylate esters (CPE) with a linear chain molecular weight of=12000 g/mol and a length of side branches which correspond to a molecular weight of =750 g/mol. The supramolecular mechanism of nanosteric van der Waals repulsive forces begins to be detected at a distance of =11 nm, and the elasticity of the lateral branches of innovative CPE is = 5 nm. Individual segments of CPE macromolecules enter the diffuse layer of dispersed nanosystems due to lateral interactions of anions of functional groups, hydrophobic fragments, etc.; they enhance the plasticizing effect of cement binders in concrete nanocompositions. Discussion. When using superplasticizing CPE, the density of concrete nanocomposites can be increased by reducing the amount of water mass to the cement mass ratio to the optimal 0.3; at the same time, technological pumpability and reliability control of the joint hardening kinetics with fillers are preserved within the framework of the technological problems system solutionsconcept. Supramolecular interaction of «anchoring» functional groups of polyacrylic acid containing solid phase cations of cement microparticles, fractal clusters of calcium hydrosilicates and simultaneous steric stabilization of polyethylene glycol radicals give the necessary rheological characteristics to construction nanocompositions and allow the construction of high-strength 55+80 MPa building materials. Conclusions. The branched comb-like nanostructure of polycarboxylate esters exhibits effective technological characteristics of superplasticizers for concrete, building mortars and dry building mixes.
PDF
