Proton-conducting membranes based on CsH2PO4 and copolymer of tetrafluoroethylene with vinylidene fluoride

In this work, proton conductivity, morphology and mechanical properties of (1–x)CsH2PO4–xF-42 (x=0.05–0.3, weight ratio) membranes were investigated for the first time. Thin flexible membranes for x≥0.15 with the uniform distribution of the components were obtained by a tape casting method. Mechanical properties of the membranes were measured by Vickers microhardness tests for a low polymer content (x˂0.15), also the tensile strength for membranes with high polymer content x=0.2–0.3 were evaluated. Proton conductivity of the (1–x)CsH2PO4–xpF-42 composite polymer electrolytes decreases monotonically with increasing x due to the effect of a «conductor-insulator» percolation. The combination of conductivity, mechanical strength and hydrophobic properties of (1–x)CsH2PO4–xF-42 makes certain compositions of proton-conducting membranes (x~0.2–0.25) promising for their use in intermediate-temperature fuel cells, despite decreased conductivity

Fortification of food with micronutrients: development of methodological and regulatory framework in the Russian Federation

The available scientific literature, domestic and international regulatory codes of normative documents concerning the fortification of various types of food products have been analyzed. The groups of food products of conventional and regular consumption included into the diets of all categories of consumers, recommended for fortification with essential micronutrients, have been determined: wheat and cereal flour (spelt wheat, buckwheat, oat, corn flour, etc.); pastry; milk and dairy products, including ice cream; non-alcoholic soft drinks; mineralized drinking water; fruit and vegetable juices; fat and oil products (vegetable oils, margarines, spreads, mayonnaise); confectionery and sweets (pastry, sugar, chocolate); cereals (breakfast cereals, muesli, ready-to-eat extruded cereals, instant pasta and cereals, mixtures for bakery, flour for sweet pastry); food concentrates (jelly, instant drinks, concentrates of sweet foods, instant food, instant cereal concentrates); table salt. The groups of food products assigned for certain categories of population are used as part of therapeutic diets for patients with various diseases (metabolic disorder syndrome, cardio-vascular system pathology with atherosclerotic vascular injury, type 2 diabetes mellitus, gastrointestinal tract diseases, non-alcoholic fatty liver disease, diabetic nephropathy, etc.), as well as assigned to reduce the risk of diseases developing, the nutrients are recommended for targeted fortification of certain types of food. Examples of micronutrients fortification of sausages and minced meat semifinished products are given below. Requirements for fortification of mass consumption food products and for fortification of foods for special dietary uses are formulated in this article, the amount of fortifying components in the various groups of food products are justified, ensuring their efficiency for improving the micronutrient status and safety of its consumption. Based on the analysis of the available scientific literature, domestic and international regulatory framework of normative documents on fortification of various types of food products, recommendations have been developed for fortification of food with micronutrients

The use of comet assay for measurement of DNA integrity in clinical and applied research

Single cell gel electrophoresis or comet assay combined with enzymes of excision repair is a method for measuring DNA strand breaks and oxidative damage. Using this approach we analysed ineffective hematopoiesis in patients with low-risk MDS. Refractory anemia (RA) exhibited a higher DNA instability in bone marrow cells when compared to controls and the extent of DNA fragmentation correlated with cytopenia. No similar relationship was observed in RA with ring sideroblasts (RARS), although the levels of DNA breaks markedly exceeded even the values detected in RA. Both groups of patients also showed high levels of oxidative damage to DNA. However, there was no clear relationship to the levels of serum ferritin, cytopenia or associated inflammation. This suggested that the oxidative DNA damage per se is not responsible for extensive apoptosis in low-risk MDS. In any case, it undoubtedly contributes to genome instability and disease progression. The second part of thesis was aimed to the impact of air pollution and genetic polymorphisms on oxidative damage to DNA, lipids and proteins of city bus drivers and garagemen. Both groups exhibited a higher level of DNA breaks and oxidative damage to proteins than the controls, while an increased level of lipid peroxidation was detected only in bus drivers. The..

Investigation of the mechanical properties of composite polymer electrolytes based on CsH

The mechanical properties of the CsH2PO4 and hybrid compounds with different polymers (SKF-26, UPTFE, Butvar B-98) was determined by the Vickers microhardness test for the first time. It was shown that increase in the volume fraction of the polymer results in the low HV values corresponding to the high robustness of the membranes to plastic deformation. Mechanical properties of hybrid compounds depend on polymer type and the best results were obtained for SKF-26. The improvement of mechanical properties makes the investigated composite polymer electrolytes promising for use as proton-conducting membranes in the medium-temperature range

Stabilization of the (C2H5)4NHSO4 High-Temperature Phase in New Silica-Based Nanocomposite Systems

In this study, the electrotransport, thermal and structural properties of composite solid electrolytes based on (C2H5)4NHSO4 plastic phase and silica (1 − x)Et4NHSO4−xSiO2, where x = 0.3–0.9) were investigated for the first time. The composites were prepared by mechanical mixing of silica (300 m2/g, Rpore = 70Å) and salt with subsequent heating at temperatures near the Et4NHSO4 melting point. Heterogeneous doping is shown to change markedly the thermodynamic and structural parameters of the salt. It is important that, with an increase in the proportion of silica in the composites, the high-temperature disordered I41/acd phase is stabilized at room temperature, as this determines the properties of the system. Et4NHSO4 amorphization was also observed in the nanocomposites, with an increase in the matrix contents. The enthalpies of the endoeffects of salt melting and phase transitions (160 °C) changed more significantly than the Et4NHSO4 contents in the composites and completely disappeared at x = 0.9. The dependence of proton conductivity on the mole fraction reached a maximum at x = 0.8, which was three or four orders of magnitude higher than the value for pure Et4NHSO4, depending on the composition and the temperature. The maximum conductivity values were close to those for complete pore filling. The conductivity of the 0.2Et4NHSO4-0.8SiO2 composite reached 7 ∗ 10−3 S/cm at 220 °C and 10−4 S/cm at 110 °C

Questions of control of hormone content in fish and other aquatic organisms (metaanalysis)

Between 1995 and 2018, the production of fish and fishery products using feed increased from 12 to 54.3 million tons. In the cultivation of such products in many countries, hormones are widely used as growth stimulants to increase the efficiency of feed conversion for the purpose of sex reversal, as well as for artificial reproduction. Hormones, especially their synthetic forms, are poorly metabolized in the marine organisms, which leads to their accumulation in the food matrix. When they enter the human body, they are capable of accumulation in tissues, affect the endocrine system and can cause the development of a number of metabolic disorders. The possibility of a carcinogenic effect of hormones has been proven. The data presented substantiate the need to control the content of hormones in fish and fish products, develop highly sensitive methods for their detection, establish a list of controlled hormones and hormone-like drugs and safety regulations for food products produced with their use. The most sensitive and accurate method in this case is the HPLC-MS/MS method. We believe that for natural (non-synthetic hormones) and synthetic hormones, the criterion for their absence in the sample should be the sensitivity threshold of the used research method (at least 20 ng/kg)

Proton-Conducting Membranes Based on CsH2PO4 and Copolymer of Tetrafluoroethylene with Vinylidene Fluoride

Received: 27.06.22. Revised: 15.07.22. Accepted: 15.07.22. Available online: 19.07.22.In this work, proton conductivity, morphology and mechanical properties of (1–x)CsH2PO4–xF-42 (x=0.05–0.3, weight ratio) membranes were investigated for the first time. Thin flexible membranes for x≥0.15 with the uniform distribution of the components were obtained by a tape casting method. Mechanical properties of the membranes were measured by Vickers microhardness tests for a low polymer content (x˂0.15), also the tensile strength for membranes with high polymer content x=0.2–0.3 were evaluated. Proton conductivity of the (1–x)CsH2PO4–xpF-42 composite polymer electrolytes decreases monotonically with increasing x due to the effect of a «conductorinsulator » percolation. The combination of conductivity, mechanical strength and hydrophobic properties of (1–x)CsH2PO4–xF-42 makes certain compositions of proton-conducting membranes (x~0.2–0.25) promising for their use in intermediate-temperature fuel cells, despite decreased conductivityThis work was supported by the Russian Science Foundation (grant no. 21-73-00298)

Aluminium: Food-related health risk assessment of the consumers

Aluminum is the most abundant metal in the lithosphere, constituting 8 % of the earth's crust. Aluminum enters the food from the various objects of environment such as water, food contact materials (packaging materials, cooking vessels), aluminum-containing food additives. In raw food products the content of aluminum is less than 5.7 mg/kg of the product. Normally, aluminum is not practically found in a human body. However, within the last decade various toxic effects of aluminum on human body have been revealed, and they are able to cause the risk of various diseases. The analysis of the available data has demonstrated that the excessive entry of aluminum in human body with food items is associated first of all with the content of aluminum-containing food additives, as well as with the use of materials and products made of aluminum and its alloys intended for contact with food. High level of aluminum consumption has been also detected among children of all ages. At the same time, today, theprovisional tolerable weekly intake (PTWI) of aluminum for children is not established. To reduce negative effect of aluminum on human body it is necessary to: * exclude from the list of Annex 2 of the Technical Regulations of the Customs Union "Requirements for Food Additives, Flavorings and Technological Aids” (TR TS 029/2012) the following food additives – potassium aluminum silicate (E555), bentonite (E558), sodium aluminum silicate (E554), potassium aluminum silicate (E555), calcium aluminum silicate (E556), aluminum silicate (kaolin) (E559); * to develop requirements for the aluminum content in food products intended for children nutrition; * to obtain data on aluminum content in food items sold on the domestic market and to assess health risks to consumers

Separate quontitative determination of organic and non-organic arsenic in sea products

The performed research is truly vital, as As (arsenic) concentration in food products is now of great interest. The US ATSDR and EPA enlist As among the most toxic substances which are dangerous for human health. We suggest a procedure for separate quantitative mass fraction determination for organic (oAs) and non-organic (iAs) arsenic compounds in sea products with solid phase extraction (SPE) application combined with atomic adsorption spectrometry. Samples were prepared according to the following procedure: liquid extraction phase with simultaneous As (III) oxidation into As (IV) with hydrogen peroxide and As (V) extraction into a 0.055 M liquid phase with hydrochloric acid. Arsenic organic and non-organic compounds were separated via solid phase extraction with Strata SAX cartridges (Sorbent Lot Number: S208-0058). To quantitatively assess the obtained samples, we applied atomic-adsorption techniques for As determination with "KVANT-2A-GRG" spectrometer according to the State Standard 51766-2001. We revealed that common As concentration didn't conform to fixed standards in 8 out of 17 analyzed samples (2 shrimps, 1 crab, 1 fish, and 4 seaweeds). However, iAs concen-tration was significantly lower than oAs concentration in all the samples. 6 out of 17 analyzed samples didn't contain any iAs within detection limits (0.1 mg/kg), and apparently all the As concentration occurred due to its organic compounds. The suggested procedure for separate oAs and iAs detection is relatively simple in terms of devices applied in it, and quite cheap, as SPE cartridges needed to perform it can be re-used after re-conditioning. This procedure, after a proper metrological validation, can be implemented in most laboratories which are certified to examine chemical safety of food products