A comprehensive review on green synthesis of titanium dioxide nanoparticles and their diverse biomedical applications

Metal oxide nanoparticles (NPs) have found a variety of applications in numerous industrial, medical, and environmental fields s, attributable to recent advances in the nanotechnology field. Titanium dioxide nanoparticles (TiO2-NPs) have gained importance as metal oxide NPs due to their potential in various fields, particularly nanomedicine and other biomedicine fields. Several studies have confirmed that NPs produced via the biosynthesis route using natural resources have significant advantages such as fewer toxic contaminants, less subsequent complex chemical synthesis, environmental friendliness, cost-effectiveness, and stability when compared to NPs produced by conventional methods, and its production with controlled shapes and sizes. Therefore, considerable effort is being expended to implement biological synthesis methods with these proven advantages. TiO2-NPs can be made using a variety of biological, chemical, and physical methods. Physicochemical methods are costly, emit high levels of toxic chemicals into the atmosphere, and consume a lot of energy. On the other hand, the biological approach is an environmentally safe, cost-effective, dependable, convenient, and easy way to synthesize TiO2-NPs. In this review, the bio-mediated synthesis, as well as various biomedical applications of TiO2-NPs, were discussed.

The ecological and economic achievements in landscape optimization of technogenic reliefs

Mining and accumulation of industrial and household waste on the earth’s surface form the technogenic relief of the planet. The main forms of violation of the natural relief are quarries, ditches, landfills and spoil tips. There are two ways of landscape optimization in order to restore ecological balance, to turn the aggressive terrain into an ecological and economic value. The first is a return to the original natural landscape. The process is implemented by ground filling of technogenic depressions, removal and chemical and technological processing of waste accumulated at landfills and spoil tips. The second way is to use technogenic relief to form a new natural landscape. The main attention of the article is paid to the optimization of technogenic landscapes by forest plantations and forest reclamation. As a result of these activities, environmentally safe and aesthetically expressive spaces are formed. Most of these facilities have a high potential for economic, socio-economic and recreational use. The outstanding world achievements in this field are considered. Their ecological and economic characteristics are given.

Bacteriome Diversity of Blackflies’ Gut and Association with Onchocerca volvulus, the Causative Agent of Onchocerciasis in Mbam Valley (Center Region, Cameroon)

Vector control using larvicides is the main alternative strategy to address limits of preventive chemotherapy using ivermectin for the control of onchocerciasis. However, it remains substantially limited by implementation difficulties, ecological concerns and the resistance of vector populations. Therefore, efficient and environmentally safe alternative control strategies are still needed. This study explores the composition of the blackfly bacteriome and its variability in the presence of Onchocerca volvulus infection, in order to determine their potential as a novel vector control-based approach to fight onchocerciasis. An entomological survey of a collection of samples was performed in the Bafia health district, a historical endemic focus for onchocerciasis in Cameroon. A total of 1270 blackflies were dissected and the infection rate was 10.1%, indicative of ongoing transmission of onchocerciasis in the surveyed communities. Sequencing process of blackflies’ gut DNA for bacteria screening revealed 14 phyla and 123 genera, highlighting the diversity of gut blackflies bacterial communities. Eight bacteria formed the core of blackfly bacteriome and Wolbachia was the predominant genus with 73.4% of relative abundance of blackflies’ gut bacterial communities. Acidomonas and Roseanomas genera were significantly abundant among infected blackflies (p = 0.01), whereas other genera such as Brevibacterium and Fructobacillus were associated with the absence of infection (p = 0.0009). Differences in gut bacterial distribution of blackflies according to their infection status by the parasite suggest a causal relationship between the bacteriome composition and the onset of blackflies’ infection by O. volvulus or vice versa. Blackfly native bacteria are then potentially involved in infection by O. volvulus, either by facilitating or preventing the parasite infestation of the vector. These bacteria represent an interesting potential as a biological tool/target for a novel approach of vector control to fight onchocerciasis.

Upgrading of heavy crude oil in supercritical aqueous fluid in the presence of activated charcoal

The article presents the results of deep processing of heavy crude oil in supercritical aqueous fluid, which makes it possible to significantly reduce the content of sulfur and resinous asphaltene compounds in products, and to increase the yield of light fuel fractions. The possibility of reducing the temperature of upgrading of heavy crude oil due to the presence of active charcoal in the reaction medium is shown. The proposed technology provides environmentally safe and residue-free processing of heavy oil and further production of high-quality hydrocarbon raw materials enriched in low-boiling fractions. Keywords: upgrading; heavy crude oil; supercritical aqueous fluid; activated charcoal.

Phytonematodes as a limiting biotic factor of agricultural production in the world (review)

Purpose. To analyze domestic and foreign scientific literature on the species composition and harmfulness of the world's most dangerous parasitic species of phytonematodes in crops. Results. Today, according to the available literature, the most dangerous species of phytonematodes include: gall nematode (Meloidogyne spp.), cyst-forming nematode (Heterodera spp. and Globodera spp.), root lesion nematode (Pratylenchus spp.), banana drill nematode (Radoholus similis), stem nematode (Ditylenchus dipsaci), pine stem nematode (Bursaphelenchus xylophilus), reniform nematode (Rotylenchulus reniformis), xiphinema index (Xiphinema index), false head nematode (Nacobbus aberrans), and rice leaf nematode (Aphelenchoides besseyi). Conclusions. The results of research on the prevalence and harmfulness of parasitic nematode species in crops convince us of the need for a more detailed study of this group of microorganisms. Due to the rapid development of molecular genetic methods in the last decade, scientists have been able to expand and improve their knowledge of identifying species, races and pathotypes of phytonematodes, their biological and environmental characteristics, and most importantly, to discover and understand extremely complex mechanisms of parasite and host plants. Nematologists are confident that further research in these and other areas in the future will create a basis for developing a new strategy for long-term and environmentally safe control of these dangerous plant parasites.

Valorization of Tomato Residues by Supercritical Fluid Extraction

Tomato processing leads to the production of considerable amounts of residues, mainly in the form of tomato skins, seeds and vascular tissues, which still contain bioactive molecules of interest for food, pharmaceutical and nutraceutical industries. These include carotenoids, such as lycopene and β-carotene, tocopherols and sitosterols, among others. Supercritical fluid extraction is well positioned for the valorization of tomato residues prior to disposal, because it remains an environmentally safe extraction process, especially when using carbon dioxide as the solvent. In this article, we provide an extensive literature overview of the research on the supercritical fluid extraction of tomato residues. We start by identifying the most relevant extractables present in tomatoes (e.g., lycopene) and their main bioactivities. Then, the main aspects affecting the extraction performance are covered, starting with the differences between tomato matrixes (e.g., seeds, skins and pulp) and possible pretreatments to enhance extraction (e.g., milling, drying and enzymatic digestion). Finally, the effects of extraction conditions, such as pressure, temperature, cosolvent, flow rate and time, are discussed.

Advances in Lipid Extraction Methods—A Review

Extraction of lipids from biological tissues is a crucial step in lipid analysis. The selection of appropriate solvent is the most critical factor in the efficient extraction of lipids. A mixture of polar (to disrupt the protein-lipid complexes) and nonpolar (to dissolve the neutral lipids) solvents are precisely selected to extract lipids efficiently. In addition, the disintegration of complex and rigid cell-wall of plants, fungi, and microalgal cells by various mechanical, chemical, and enzymatic treatments facilitate the solvent penetration and extraction of lipids. This review discusses the chloroform/methanol-based classical lipid extraction methods and modern modifications of these methods in terms of using healthy and environmentally safe solvents and rapid single-step extraction. At the same time, some adaptations were made to recover the specific lipids. In addition, the high throughput lipid extraction methodologies used for liquid chromatography-mass spectrometry (LC-MS)-based plant and animal lipidomics were discussed. The advantages and disadvantages of various pretreatments and extraction methods were also illustrated. Moreover, the emerging green solvents-based lipid extraction method, including supercritical CO2 extraction (SCE), is also discussed.

STRENGTHENING THE FOUNDATIONS OF PHYSICALLY OBSOLETE BUILDINGS

The problems and prospects of existing methods of strengthening the foundations of physically obsolete buildings are outlined, which is relevant for the preservation of buildings of architectural and historical value, as well as for mass renovation in large cities in cramped conditions with a high density of existing buildings. Method of calculation of hollow rectangular and round sections filled with concrete during bending is considered. In this article the dependence of compacted zone radius on initial characteristic of soil density and diameter of pressed pipe concrete element is analyzed. The conclusion is formed that the method of arrangement of the pipe-concrete horizontal distributor for simultaneous reinforcement of soil of the base and foundations chosen for the study allows to regulate the process of leveling the building settlement as a whole, and is also the most environmentally safe and does not negatively affect the surrounding buildings and structures.

Potential technological solution for sampling the bottom sediments of the subglacial lake Vostok: relevance and formulation of investigation goals

The subglacial Lake Vostok in Antarctic is a unique natural phenomenon, its comprehensive study involves sampling of water and bottom surface rocks. For further study of the lake, it is necessary to drill a new access well and develop environmentally safe technologies for its exploration. This article discusses existing and potential technologies for sampling bottom surface rocks of subglacial lakes. All these technologies meet environmental safety requirements and are conducive for sampling. The authors have proposed an alternative technology, using a walking device, which, due to its mobility, enables selective sampling of rocks across a large area from a single access well. The principal issues, related to the implementation of the proposed technology, are investigated within this article. This report is prepared by a team of specialists with many years of experience in drilling at the Vostok Station in Antarctic and in experimental work on the design of equipment and non-standard means of mechanization for complicated mining, geological and climatic conditions.