A new technology for the production of isoprene from isobutene-containing C4 fractions and formaldehyde: Prospects for industrial reconstruction

The industrially implemented process of isoprene production from isobutene-containing C₄ fractions and formaldehyde, which includes the gas-phase high-temperature decomposition of an intermediate, 4,4-dimethyl-1,3-dioxane, is expensive and obsolete. We propose a new technology that requires the same precursors and allows for a reduction in the cost of isoprene by a factor of at least 1.5. It features the concurrent liquid-phase decomposition of intermediate products in a column reactor in the presence of an aqueous solution of phosphoric acid at a moderate temperature (∼160°C), and is convenient for reconstructing existing production lines.     

Quantitative Characteristics of Binding of Metal Ions by Polyamide Fibres

Based on the data on chemical binding of the salts of ten metals from aqueous solutions by polycaproamide fibres, the metal cations were divided into four groups as a function of the concentration of the salt solutions and their chemisorption power. Copper cations are most prone to chemisorption by PCA fibres and their chemisorption index is one order of magnitude higher than the index for cations of the other metals.     

Nanocarriers for Biomedicine: From Lipid Formulations to Inorganic and Hybrid Nanoparticles

Encapsulation of cargoes in nanocontainers is widely used in different fields to solve the problems of their solubility, homogeneity, stability, protection from unwanted chemical and biological destructive effects, and functional activity improvement. This approach is of special importance in biomedicine, since this makes it possible to reduce the limitations of drug delivery related to the toxicity and side effects of therapeutics, their low bioavailability and biocompatibility. This review highlights current progress in the use of lipid systems to deliver active substances to the human body. Various lipid compositions modified with amphiphilic open-chain and macrocyclic compounds, peptide molecules and alternative target ligands are discussed. Liposome modification also evolves by creating new hybrid structures consisting of organic and inorganic parts. Such nanohybrid platforms include cerasomes, which are considered as alternative nanocarriers allowing to reduce inherent limitations of lipid nanoparticles. Compositions based on mesoporous silica are beginning to acquire no less relevance due to their unique features, such as advanced porous properties, well-proven drug delivery efficiency and their versatility for creating highly efficient nanomaterials. The types of silica nanoparticles, their efficacy in biomedical applications and hybrid inorganic-polymer platforms are the subject of discussion in this review, with current challenges emphasized.     

Gas‐Dynamic Method of Combustion Control and Flame Stabilization in a Pseudoliquid Fuel Flow

A gasdynamic method for controlling combustion and flame stabilization in a pseudoliquid fuel flow is proposed. The method is based on injection of additional air jets with varied frequency into a chamber with abrupt expansion. It is shown that the characteristics of combustion of the pseudoliquid fuel can be controlled by varying the frequency of injection of periodic air jets.