Different types of pockmarks, including single pockmarks, circular pockmarks, elongated pockmarks, chain-type pockmarks and compound pockmarks, were identified in coastal areas around Fujian, China. The sediments associated with pockmarks were mainly silty clay to clay, with a small quantity of silt with fine sand. The sulfate content in the pore water in the sedimentary layers associated with pockmarks decreased with depth from the surface, whereas the free methane content increased with depth. The interaction between sulfate and methane is well known, but differences in the sulfate-methane transitional zone (SMTZ) were observed in different areas with different hydrologic characteristics. The sedimentary SMTZ of the offshore Zhe-min mud wedge was shallow, at 50–70 cm below the seafloor. The sedimentary SMTZ was moderately deep (90–115 cm) in the central bay area and deep (180–200 cm) in the sandy area offshore. This variability in SMTZ depth reflects different amounts of free methane gas in the underlying formations, with a shallower SMTZ indicating a higher free methane content. The free methane had δ13C values of -26.47‰ to -8.20‰ and a biogenic-hybrid genetic type. The flux of sedimentary gas from the pockmark surfaces, calculated according to Fick’s formula, was 2.89 to 18.85 l/m2·a. The shape, size and scale of the pockmarks are directly related to the substrate type and the gas production of the underlying strata and thus vary with the sedimentary environment and development stage. Therefore, different types of pockmarks, in various phases of development, are associated with different sedimentary and dynamical conditions. A single circular pockmark forms by strong methane flux. As the intensity of methane flux weakens, the pockmark becomes elongated in the direction of the water flow because of long-term erosion induced by regular hydrodynamic forces. Finally, under weak intensity of methane flux and the influence of complex hydrodynamic conditions, pockmarks merge to form large-scale, compound pockmarks.

The class I carcinogen aflatoxin B1 (AFB1) poses a significant risk to human health. The contamination of food sources contributes to the spread of AFB1, mainly through grains and nuts, from Aspergillus flavus. The high percentage of aflatoxin contamination in various imported nuts in the Republic of Kazakhstan has encouraged researchers to develop a local method of AFB1 detoxification. This research was focused on studying the ability of Ziziphora serpyllace leaf extract growing in the Akmola region of the Republic of Kazakhstan to inactivate aflatoxin B1 in various nuts. For the first time, an extract of Ziziphora serpyllace leaves growing in the territory of the Republic of Kazakhstan was used to detoxify AFB1 in nuts, and this demonstrated low cytotoxic activity, high antimicrobial and high antifungal activity, while preserving the qualitative characteristics of the nuts.

Nuts are a staple food consumed throughout the world, and their purity is essential to maintaining human health. However, fungal mycotoxins pose one of the real challenges in keeping nuts clean for human consumption. The high cost of equipment, reagents used, standard samples, as well as increased requirements for personnel qualifications limit the use of chromatographic methods in testing laboratories, both manufacturing enterprises and organizations monitoring food safety. The present study aimed to test a new method for extracting aflatoxin B1 using sodium chloride and citric acid instead of methanol present in imported nuts obtained from local markets in Astana (Kazakhstan). The proposed method for extracting aflatoxin B1 from nuts is chemically safe, since the substances used belong to hazard class 3 of the international classification and do not require separate premises in food safety laboratories of the Astana markets and special training of specialists. The technical objective of the method is to replace the reagent (methanol) during the sample preparation process when conducting cocuret enzyme-linked immunosorbent assay. Aflatoxin B1 levels varied depending on the type of nut. Aflatoxin contamination was observed in 35.8% of samples analyzed. These levels of mycotoxin contamination are alarming and raise serious questions about the purity of imported nuts to ensure food safety.

This paper presents the results of the study of carbon films deposited on substrates of quartz, mica and silicon by the method of electron paramagnetic resonance (EPR). This study has identified the dependences of the intensities of the EPR signal, the g- factor, and the line width on the temperature of carbon films on various substrates with perpendicular and parallel arrangement of the sample plane relative to the orientation of the magnetic field are presented. The results of this study show that the dependence of the line width on temperature measurements does not change under both conditions for recording the EPR spectra. The research has also shown that with increasing temperature, the normalized intensity of the EPR signal line increases when carbon is deposited on various substrates (quartz, mica, and silicon) by the method of plasma decomposition of a mixture of CH4 and H2.