Plasmochemical process for the production of niobium and tantalum nanopowders

Niobium and tantalum powders used in modern manufacturing are materials with nanostructure. The authors have studied and optimized the process of the production of niobium and tantalum nanopowders (adjusted in the range of the particle size of 20-150 nm) at pilot scale. The process is based on the reduction reaction of pentachlorides of tantalum and niobium with hydrogen in a plasma generator at about 3500 K. To stabilize the structure and adjust the granulometric composition of the produced nanopowders thermal treatment at 1373 K under vacuum was applied. The powders are characterized by very high purity with regard to oxygen and metallic admixtures and by low bulk density (0.1-0.3 g/cm 3). The specimens had a high specific surface area (10-30 m 2/g). The process of compacting and sintering of powders was tested at temperatures from 1173 to 1373 K. The porosity of the specimens was 0.55-0.75 from the theoretical. The pore diameter was adjusted to 0.5-0.05 μm

Intracellular delivery of mRNA in adherent and suspension cells by vapor nanobubble photoporation

Efficient and safe cell engineering by transfection of nucleic acids remains one of the long-standing hurdles for fundamental biomedical research and many new therapeutic applications, such as CAR T cell-based therapies. mRNA has recently gained increasing attention as a more safe and versatile alternative tool over viral- or DNA transposon-based approaches for the generation of adoptive T cells. However, limitations associated with existing nonviral mRNA delivery approaches hamper progress on genetic engineering of these hard-to-transfect immune cells. In this study, we demonstrate that gold nanoparticle-mediated vapor nanobubble (VNB) photoporation is a promising upcoming physical transfection method capable of delivering mRNA in both adherent and suspension cells. Initial transfection experiments on HeLa cells showed the importance of transfection buffer and cargo concentration, while the technology was furthermore shown to be effective for mRNA delivery in Jurkat T cells with transfection efficiencies up to 45%. Importantly, compared to electroporation, which is the reference technology for nonviral transfection of T cells, a fivefold increase in the number of transfected viable Jurkat T cells was observed. Altogether, our results point toward the use of VNB photoporation as a more gentle and efficient technology for intracellular mRNA delivery in adherent and suspension cells, with promising potential for the future engineering of cells in therapeutic and fundamental research applications

Indoor Air Quality in Industrial Premises

The study focuses on indoor air quality (microclimate, chemicals) in industrial premises. The health risks are determined. A model with numerical criteria is offered to assess the level of occupational hazards (indoor air climate) using a simple/flexible risk assessment method. Practical examples and the results of measurements of microclimate (temperature, humidity, and velocity of the air) and chemical concentrations in the workplace air in five industries (mechanical, printing, wood, plastic and clothing industries) are presented. The connections between risk levels and possible health damages are presented. In the wood processing industry the concentration of solvents: toluene (1- 941 mg/ m3); xylene (2.5-347 mg/ m3); butanol (0.5- 285 mg/ m3) and styrene (1-208 mg/ m3)) is considered to be unacceptable risk for workers’ health. The model is presented for taking into consideration the concentration of chemicals in the air of the work environment and possible negative health effects. The microclimate is under control except during very warm climate in summer. The chemicals are under control in printing, mechanical (except welding in closed workrooms), and clothing industry. The simple/flexible risk assessment method is suitable for enterprises processing materials or handling chemicals in some stages, but cannot be applied for chemical plants where several other factors should be taken into account