Simulation of reverse osmosis process: Novel approaches and development trends

Reverse osmosis is an essential technological separation process that has a large number of practical applications. The mathematical simulation is significant for designing and determining the most effective modes of membrane equipment operation and for a deep understanding of the processes in membrane units. This paper is an attempt at systematization and generalizing the results of the investigations dedicated to reverse osmosis simulation, which was published from 2011 to 2020. The main approaches to simulation were analyzed, and the scope of use of each of them was delineated. It was defined that computational fluid dynamics was the most used technique for reverse osmosis simulation; the intensive increase in using of molecular dynamics methods was pointed out. Since these two approaches provide the deepest insight into processes, it is likely that they will further be widely used for reverse osmosis simulations. At the same time, for the simulation of the membrane plant, it is reasonable to use the models that required the simplest solutions methods. The solution-diffusion model appears to be the most effective and flexible for these purposes. Therefore, this model was widely used in considering the period. The practical problems solved using each of the considered approaches were reviewed. Moreover, the software used for the solution of the mathematical models was regarded

Study of the effect of the introduction of mitochondrial import determinants into the gRNA structure on the activity of the gRNA/SpCas9 complex in vitro

It has long been known that defects in the structure of the mitochondrial genome can cause various neuromuscular and neurodegenerative diseases. Nevertheless, at present there is no effective method for treating mitochondrial diseases. The major problem with the treatment of such diseases is associated with mitochondrial DNA (mtDNA) heteroplasmy. It means that due to a high copy number of the mitochondrial genome, mutant copies of mtDNA coexist with wild-type molecules in the same organelle. The clinical symptoms of mitochondrial diseases and the degree of their manifestation directly depend on the number of mutant mtDNA molecules in the cell. The possible way to reduce adverse effects of the mutation is by shifting the level of heteroplasmy towards the wild-type mtDNA molecules. Using this idea, several gene therapeutic approaches based on TALE and ZF nucleases have been developed for this purpose. However, the construction of protein domains of such systems is rather long and laborious process. Meanwhile, the CRISPR/Cas9 system is fundamentally different from protein systems in that it is easy to use, highly efficiency and has a different mechanism of action. All the characteristics and capabilities of the CRISPR/Cas9 system make it a promising tool in mitochondrial genetic engineering. In this article, we demonstrate for the first time that the modification of gRNA by integration of specific mitochondrial import determinants in the gRNA scaffold does not affect the activity of the gRNA/Cas9 complex in vitro

Влияние некоторых структурных свойств ионных жидкостей на гомогенные и гетерогенные свойства их смесей с водой и спиртами

The article presents a study of influence of the structural characteristics of ionic liquids, such as length of alkyl chain of the cation, cation's symmetry, type of the cation, type of the anion and some others, on the homogeneous and heterogeneous characteristics of the mixtures of ionic liquids with water and alcohol.В работе исследована степень влияния на гомогенные и гетерогенные свойства растворов ионных жидкостей с водой и спиртами ряда формализованных структурных признаков ионных жидкостей, таких как длина алкильного радикала катиона, степень симметричности катиона, тип катиона, тип аниона и некоторых других

Oral manifestations of systemic disease

While the majority of disorders of the mouth are centred upon the direct action of plaque, the oral tissues can be subject to change or damage as a consequence of disease that predominantly affects other body systems. Such oral manifestations of systemic disease can be highly variable in both frequency and presentation. As lifespan increases and medical care becomes ever more complex and effective it is likely that the numbers of individuals with oral manifestations of systemic disease will continue to rise. The present article provides a succinct review of oral manifestations of systemic disease. In view of this article being part of a wider BDJ themed issue on the subject of oral medicine, this review focuses upon oral mucosal and salivary gland disorders that may arise as a consequence of systemic disease

Credit Rationing with Symmetric Information

Without denying the importance of asymmetric information, this article purports the view that credit rationing may also originate from a lender's inability to classify loan applicants in proper risk categories. This effect is particularly strong when novel technologies are involved. Furthermore, its relevance may increase with the importance assigned to internal rating systems by the Basel accord. This article presents a measure of the inadequacy of a lender's classification criteria to the qualitative features of prospective borrowers. Even without information asymmetries, credit rationing may occur if this quantity reaches too high a value. Furthermore, some general principles are outlined, that may be used by lenders in order to change their classification criteria