Portable biomimetic sensor devices for the express control of phenols content in water were developed. The synthetic binding sites mimicking active site of the enzyme tyrosinase were formed in the ...structure of free-standing molecularly imprinted polymer membranes. Molecularly imprinted polymer membranes with the catalytic activity were obtained by co-polymerization of the complex Cu(II)–catechol–urocanic acid ethyl ester with (tri)ethyleneglycoldimethacrylate, and oligourethaneacrylate. Addition of the elastic component oligourethaneacrylate provided formation of the highly cross-linked polymer with the catalytic activity in a form of thin, flexible, and mechanically stable membrane. High accessibility of the artificial catalytic sites for the interaction with the analyzed phenol molecules was achieved due to addition of linear polymer (polyethyleneglycol Mw 20,000) to the initial monomer mixture before the polymerization. As a result, typical semi-interpenetrating polymer networks (semi-IPNs) were formed. The cross-linked component of the semi-IPN was represented by the highly cross-linked catalytic molecularly imprinted polymer, while the linear one was represented by polyethyleneglycol Mw 20,000. Extraction of the linear polymer from the fully formed semi-IPN resulted in formation of large pores in the membranes’ structure. Concentration of phenols in the analyzed samples was detected using universal portable device oxymeter with the oxygen electrode in a close contact with the catalytic molecularly imprinted polymer membrane as a transducer. The detection limit of phenols detection using the developed sensor system based on polymers–biomimics with the optimized composition comprised 0.063
mM, while the linear range of the sensor comprised 0.063–1
mM. The working characteristics of the portable sensor devices were investigated. Storage stability of sensor systems at room temperature comprised 12 months (87%). As compared to traditional methods of phenols detection the developed sensor system is characterized by simplicity of operation, compactness, and low cost.
Energy distributions and properties of the occupied and empty electronic states for a planar complex of nickel porphyrin NiP are studied by X-ray photoemission and absorption spectroscopy techniques. ...As a result of the analysis of the experimental spectra of valence photoemission, the nature and energy positions of the highest occupied electronic states were determined: the highest occupied state is formed mostly by atomic states of the porphine ligand; the following two states are associated with 3
d
states of the nickel atom. It was found that the lowest empty state is specific and is described by the σ-type
b
1
g
MO formed by empty
N
i
3
d
x
2
−
y
2
-states and occupied 2
p
-states of lone electron pairs of nitrogen atoms. This specific nature of the lowest empty state is a consequence of the donor–acceptor chemical bond in NiP.
It has been reported that muscle functional unloading is accompanied by an increase in motoneuronal excitability despite the elimination of afferent input. Thus, we hypothesized that pharmacological ...potentiation of spontaneous contractile soleus muscle activity during hindlimb unloading could activate anabolic signaling pathways and prevent the loss of muscle mass and strength. To investigate these aspects and underlying molecular mechanisms, we used β-myosin allosteric effector Omecamtiv Mekarbil (OM). We found that OM partially prevented the loss of isometric strength and intrinsic stiffness of the soleus muscle after two weeks of disuse. Notably, OM was able to attenuate the unloading-induced decrease in the rate of muscle protein synthesis (MPS). At the same time, the use of drug neither prevented the reduction in the markers of translational capacity (18S and 28S rRNA) nor activation of the ubiquitin-proteosomal system, which is evidenced by a decrease in the cross-sectional area of fast and slow muscle fibers. These results suggest that chemically-induced increase in low-intensity spontaneous contractions of the soleus muscle during functional unloading creates prerequisites for protein synthesis. At the same time, it should be assumed that the use of OM is advisable with pharmacological drugs that inhibit the expression of ubiquitin ligases.
Display omitted
•Omecamtiv Mecarbil (OM) is a selective β-myosin effector that increases muscle contractility.•An increase in rat soleus muscle electromyographic activity is known to occur after several days of hindlimb suspension.•OM partially prevents a decrease in muscle strength, supposedly by the potentiation of spontaneous contractions.•OM attenuates a decrease in the MPS rate but does not prevent an activation of the ubiquitin-proteosome system.
Results of electrolysis of antimony (99.56% Sb) in a sulfate-fluoride electrolyte are provided. Electrolysis parameters and distribution of 20 associated elements between the cathode metal, sludge, ...and electrolyte are determined. Phase composition of the sludge formed is established, and it is shown that presence of intermetallic compounds (NiSb and NiSb
2
) in refined metal promotes transfer of nickel into sludge. A balance is provided for antimony and controlled elements (Fe, Ni, As, Pb, Sn) for the electrolysis products. Volumes of electrolyte involved in electrowinning with an insoluble anode and solution utilization are substantiated. A production scheme for preparation of antimony grade Su00 is proposed and established. The scheme includes stages of pyrometallurgical refining, anode casting, electrolysis, electro-winning with an insoluble anode, and deposition of impurities (neutralization). Direct extraction of antimony into cathode metal in the electrolysis stage is 97.9%.
•Biopolymer layer-by-layer nanocoatings change the surface properties of nitinol plates.•Using κ-carrageenan as the top layer reduces hydrophobicity and surface roughness.•The use of chitosan as the ...lower layer of the film allows increasing the stability polymer coatings on the nitinol.•Chitosan/carrageenan films that were applied to nitinol plates reduce cytotoxicity in relation to the MG-63 cells line.
Thin films based on the natural polysaccharides κ-carrageenan (Carr) and chitosan (Chit) were formed by layer-by-layer deposition technique. Surface topography and mechanical characteristics (Young's modulus, adhesion strength) of the polymer films with different number of layers were determined using various modes of atomic force microscopy (AFM). Polymer films were used to deposit on the surface of nitinol (NiTi) plates. The creation of polysaccharide coatings on nitinol led to a change in surface properties, such as hydrophilicity and root mean square roughness. in vitro cytotoxicity assay for nitinol plates with and without polymer coating by the MG-63 osteoblast-like cell line was conducted and was shown that all the studied samples are not toxic. A decrease in cytotoxicity for samples with a polymer film consisting of 4 layers of chitosan and carrageenan was shown as compared to an uncoated nitinol plates.
The article raises the problem of ensuring metrological traceability of quality and nutritional value measurement results for food products and food raw materials: water (moisture), nitrogen ...(protein, crude protein), fat, ash and carbohydrate content. The problem under consideration can be solved by applying reference materials of food composition, traceable to state primary measurement standards GET 173-2017 and GET 176-2019 and primary reference measurement procedures (PRMP), for attestation of measurement procedures and accuracy verification of measurement results. The article discusses the results of PRMP development for measuring mass fraction of fat, ash and carbohydrates in food products and food raw materials, and mass fraction of crude fat (oil content) in oilseeds and products based on them. The paper also presents metrological characteristics of reference materials of the composition of dried dairy products, dried grain and dairy-grain cereals for babies, egg powder, freeze-dried meat products, animal feed. The results of the work allow for building a chain of metrological traceability from GET 173-2017, GET 176-2019 and PRMP to routine measurement procedures, thereby ensuring the uniformity of measurements of nutritional value of food products.
Microbiological and biochemical processes caused by yeast are the main factors affecting the quality of bread. The ability to manage the vital activity of yeast allows you to regulate these processes ...and contribute to the intensification of technological processes in baking. An important factor that affects the activity of yeast is oxygen. In bread-making technology, oxygen is mainly considered as a factor that affects oxidative processes. The effect of aeration of bakery semi-finished products on the properties of yeast has not been studied enough. In this work, we studied the enzymatic activity (zimase, maltase), morphological characteristics, viability and quantity of water-soluble sulfhydryl compounds released by yeast when the yeast suspension and liquid sourdough were saturated with oxygen in the range of 4-16 mg / l. The lifting force of yeast when the suspension was saturated with oxygen improved by 23 %. Similarly, the lifting force of liquid sourdough changed when it was saturated with oxygen. Increasing the oxygen content 3 times increased the lift of the liquid sponge by 20 %. It was found that the accumulation of total sulfhydryl compounds in the control was more intense than that in semi-finished products saturated with oxygen. In general, the oxygen content in the yeast suspension and in the liquid sponge significantly activates the vital activity of yeast and, accordingly, intensifies the process of their preparation.
—
The high-temperature (up to 1000°C) oxidation behavior of natural galena after mechanical activation has been studied by thermogravimetry, differential thermal analysis, mass spectrometry, and ...X-ray diffraction. The results demonstrate that the nature of the energy stored during mechanical activation of galena influences its reactivity. Mechanical activation has been shown to influence the morphology of galena particles, and we have compared oxidation processes during continuous heating in flowing air before and after mechanical activation.
The process of phase formation during metallothermic reduction of tin and associated metals from natural cassiterite containing 74.4% SnO
2
, 16.3% SiO
2
, and 9.3% FeCO
3
is studied by methods of ...combined thermogravimetry and differential thermal analysis (or differential scanning calorimetry), as well as Xray diffraction. Aluminum, calcium and calciumaluminum master alloy (69.4 wt.% Ca) are tested as reducing agents. The possibility is demonstrated of extracting tin from cassiterite in the form of a metal and an alloy in agreement with predicted results of thermodynamic modeling with reducing agent stoichiometric consumption. It is found that reduction of cassiterite with aluminum proceeds actively in the range 1000–1150°C, and an increase in its consumption in excess of the stoichiometric requirement hardly affects the process temperature. When using a calciumaluminum master alloy, tin from dioxide passes into the metal phase in two stages through formation of tin monoxide. Addition of aluminum to the calciumaluminum master alloy or its replacement with a mixture of metallic calcium and aluminum slightly reduces the efficiency of the reduction process.
Bioprinting can be defined as additive biofabrication of three-dimensional (3D) tissues and organ constructs using tissue spheroids, capable of self-assembly, as building blocks. The thyroid gland, a ...relatively simple endocrine organ, is suitable for testing the proposed bioprinting technology. Here we report the bioprinting of a functional vascularized mouse thyroid gland construct from embryonic tissue spheroids as a proof of concept. Based on the self-assembly principle, we generated thyroid tissue starting from thyroid spheroids (TS) and allantoic spheroids (AS) as a source of thyrocytes and endothelial cells (EC), respectively. Inspired by mathematical modeling of spheroid fusion, we used an original 3D bioprinter to print TS in close association with AS within a collagen hydrogel. During the culture, closely placed embryonic tissue spheroids fused into a single integral construct, EC from AS invaded and vascularized TS, and epithelial cells from the TS progressively formed follicles. In this experimental setting, we observed formation of a capillary network around follicular cells, as observed during in utero thyroid development when thyroid epithelium controls the recruitment, invasion and expansion of EC around follicles. To prove that EC from AS are responsible for vascularization of the thyroid gland construct, we depleted endogenous EC from TS before bioprinting. EC from AS completely revascularized depleted thyroid tissue. The cultured bioprinted construct was functional as it could normalize blood thyroxine levels and body temperature after grafting under the kidney capsule of hypothyroid mice. Bioprinting of functional vascularized mouse thyroid gland construct represents a further advance in bioprinting technology, exploring the self-assembling properties of tissue spheroids.
PDF
