Nephrostomy tube misplacement in the inferior vena cava following percutaneous nephrostomy

Percutaneous renal interventions are characterized by bleeding and infectious complications, as well as trauma to organs located near the kidney, renal or inferior vena cava (IVC). The article presents a clinical observation of a rare complication of percutaneous nephrostomy (PCN), i.e. migration of the distal end of the nephrostomy tube into the IVC. Its timely removal followed by re-nephrostomy made it possible to avoid bleeding and restore drainage of the pyelocalyceal system. Along with this, the article presents a literature review on this condition in the eLibrary, Springer, MedLine, Embase, UpToDate databases from 2000 to 2021. The indications for PCN, the frequency and risk factors of IVC damage during percutaneous renal interventions, as well as treatment tactics were studied. After the initial evaluation of the literature, ten articles were selected for further analysis. The main risk factors associated with IVC perforation after PCN include the surgeon's lack of experience in instrumental imaging, misjudgment of the length of the nephrostomy tube, and its insertion depth, resulting in its inadequate placement. Removal of the nephrostomy tube from the IVC under radiological and ultrasound guidance or open surgery are the main methods to correct for this complication

Термодинамический и кинетический анализ химического сопряжения с реакцией дегидрирования метанола в формальдегид

Theoretical analysis of the possibility of conjugating the reaction of formaldehyde formation via dehydrogenation of methanol with other initiating reactions is conducted; and advantages of using hydrogen peroxide vs. organic inductors are discussed. When hydrogen peroxide is used, the reaction reaches stationary condition almost immediately. It is demonstrated that the induction and the targeted reaction proceed with high selectivity towards formaldehyde.Проведен теоретический анализ возможности сопряжения с реакцией обычного дегидрирования метанола в формальдегид различных реакций, инициирующих протекание целевого процесса. Показано преимущество перекиси водорода перед индукторами органического происхождения. При применении перекиси водорода стационарный режим реакции устанавливается практически мгновенно. Установлено, что инициированный процесс сводится к одновременному протеканию индуктирующей и целевой реакций с высокой селективностью по формальдегиду

Каталитические превращения биоэтанола. Обзор

It is shown that biomass of different type can be processed into valuable products of organic and petrochemical synthesis and monomers of synthetic rubber in order to provide an alternative to the use of oil. The key technological, economical, ecological problems of bioethanol processing were stated. The analysis of development of new generation catalysts for motor fuels and hydrocarbons production from bioethanol is made.Показана принципиальная возможность комплексной переработки биомассы различного типа в ценные продукты органического, нефтехимического синтеза и мономеры синтетического каучука с целью альтернативной замены нефти. Сформулированы ключевые технологические, экономические и экологические проблемы по процессам превращения биоэтанола. Проведен анализ развития синтеза катализаторов нового поколения для процессов получения моторного топлива и углеводородов различных классов из биоэтанола

Смешанные M-V-Sb-оксиды как катализаторы оксидегидрогенизаци

The properties of mixed M-V-Sb (M = Ni, Co, Bi, Sn) oxides, supported on aluminum oxide, have been physically characterized and their activities estimated .in dehydrogenation of light paraffins, ethyl benzene and ethanol. The most selective NiVSb catalyst was easily reduced which allowed for proposing of the reduction-oxidation mechanism .The result of kinetic researches has shown that, the concentration of oxygen in the gas phase is the key parameter responsible for dehydrogenation selectivity. To maintain the optimal process conditions, oxygen was distributed along the catalyst layers.Смешанные M-V-Sb-оксиды ( M = Ni, Co, Bi, Sn), нанесенные на оксид алюминия, были физически охарактеризованы в свойствах и оценены по активности в реакции дегидрирования легких пара-финов, этилбензола и этанола. Наиболее селективный катализатор Ni-V-Sb легко восстанавли-вался, что позволило выдвинуть предположение об окислительно-восстановительном механизме реакции. Результаты кинетических исследований показали, что концентрация кислорода газовой фазы является ключевым параметром, ответственным за дегидрирующую селективность. Для под-держания указанного оптимума использовалась распределенная подача кислорода по слою катализатора

Окислительное дегидрирование изобутана в изобутен на Ni-V-Sb-алюмооксидном катализаторе.

Addition of nickel oxide in the V-Sb/γAl2O3 catalytic system, used in oxidative dehydrogenation of isobutane, significantly increases conversion (from 36 to 42-44%) at isobutene selectivity of 70 %. The developed catalysts consisting of systems V-Sb-O and V-Sb-Ni-O were characterized using XRD, XPS, and H2-TPR. Formation of the discovered nickel vanadate phase NiV2O6 is as a result of free phase VOx is a more effective catalyst due to increase in the quantity of mobile oxygen lattice. It is suggested that the set of various vanadium surface phases improves activity and selectivity of the new catalytic systems.Включение дополнительно оксида никеля в каталитическую систему V-Sb/γAl2O3, используемую в окислительном дегидрировании изобутана, значительно увеличивает конверсию (от 36 до 42-44%) при селективности по изобутену 70%. Разработанные катализаторы, включающие системы V-Sb-O и V-Sb-Ni-O, были охарактеризованы методами БЭТ, XRD, XPS и H2-TPR. Формирование обнаруженной фазы ванадата никеля NiV2O6 приводит за счет свободной фазы VOx к более эффективному катализатору вследствие увеличения количества мобильного кислорода решетки. Предполагается, что набор разновидностей поверхностных фаз ванадия улучшает активность и селективность новой каталитической системы

КАТАЛИТИЧЕСКАЯ КОНВЕРСИЯ БИОЭТАНОЛА В АРОМАТИЧЕСКИЕ УГЛЕВОДОРОДЫ В ПРИСУТСТВИИ ПЕРОКСИДА ВОДОРОДА

The initiating action of hydrogen peroxide on the catalytical transformation of ethanol into aromatic hydrocarbons was studied. It was shown that the total yield of aromatic hydrocarbons increases with increasing time of contact and temperature, when rapid coking of the surface of the zeolite-containing catalyst HZSM-5 occurs in the absence of hydrogen. The modifying action of hydrogen peroxide by the catalyst surface hydroxylation and initiation of the rate-limiting step of ethylene oligomerization with the participation of peroxide radicals HO2 • was hypothesized.Исследовано инициирующее влияние пероксида водорода на процесс каталитического пре-вращения этанола в ароматические углеводороды. Показано, что суммарный выход арома-тических углеводородов повышается с увеличением времени контакта и температуры в тех условиях, когда в отсутствие пероксида водорода происходит быстрое коксование поверх-ности цеолитсодержащего катализатора HZSM-5. Высказана гипотеза о модифицирующем действии пероксида водорода путем гидроксилирования поверхности катализатора и инициировании лимитирующей стадии олигомеризации этилена с участием пероксидных радикалов HO2•

Каталитическая конверсия биоэтанола в углеводороды

The fundamentals of catalytic bioethanol conversion into gasoline products, ethylene and aromatic hydrocarbons are studied. New catalysts on the basis of HZSM-5 are synthesized for these purposes. The scheme of the mechanism of process key stages is offered. The possibility of catalytic hydrogenation of mixture of aromatic hydrocarbons contained in products of bioethanol conversion into motor fuel is demonstrated.Изучены основные закономерности каталитической конверсии биоэтанола в продукты бензинового ряда, этилен и ароматические углеводороды. Синтезированы новые катализаторы на основе HZSM-5 для этих целей. Предложена схема механизма ключевых этапов процесса. Показана принципиальная возможность каталитического гидрирования смеси ароматических углеводородов, содержащихся в продуктах конверсии биоэтанола, в моторное топливо

Spectroscopic evaluation of carbohydrate levels in cell line treated with red microalgal polysaccharides

Abstract. Sulfated polysaccharides obtained from red microalgae proved to be as potent antiviral agents against various viruses. The huge molecular weight of these polysaccharides contributed much to the difficulty in explaining and understanding the mechanism of their activity against internal steps in the replication cycle of these viruses. In the present study we used microscopic Fourier-Transform Infrared Spectroscopy (FTIR) to investigate: (a) possible penetration of these polysaccharides into the treated cells, (b) effect of the polysaccharides treatment on some metabolic changes in these cells. Our results show a rapid accumulation of carbohydrates in the treated Vero cells. The carbohydrates level in these cells increases continuously after treatment during the entire experiment time period. In addition, we noted a gradual shift of PO2-ionized symmetric stretching peak of Vero cells to the position found in primary cells as a result of the continuous treatment with the microalgal polysaccharides

The anatomy of the renal lower calyceal group influence on the risk of residual stones in the Urolithiasis treatment

Background. There are various data in the literature regarding the boundary values of the width and length of the neck, as well as the angle between the pelvis and infundibulum. These parameters distinguish between patients with high and low risk of residual fragments.Objectives. The purpose of this study is to examine the lower calyceal group anatomy of patients without kidney stones and to compare the obtained results with previously published one. Materials and methods. Retrospective stage: Computed tomography (CT) scan of the abdomen was obtained in 120 patients (which was performed on them from March 2018 to 2019). CT scans of 100 patients (200 kidneys) were included in analysis after exclusion of inappropriate data. The infundibulopelvic angle was measured using the two most common methods by Sampaio and by Elbahnasy. Also, the length and width of the lower infundibulum were measured. All results were divided into four groups depending on the Sampaio classification of pyelocaliceal system (PCS). Results. The average value of the infundibulopelvic angle according to the Elbahnasy’s method is 74.1±15.1, and according to the Sampaio method is 101.8±20.1. When measured by the Elbahnasy method, an angle of more than 90 ° is more likely to occur with A1 structure variant, and less than 90 ° is more likely to occur in the PCS corresponding to the A2 variant. The average length of the lower infundibulum is 20.7±2.8 mm. The higher value of the lower infundibulum width was in group A1. Conclusion. In our study, all parameters were out of risk of both the low success of the operation and the development of kidney stone indicated in previously published studies. This fact can confirm the influence of the anatomy of the lower calyceal group on the development of kidney stones

Thermodynamic and kinetic analysis of the chemical reaction of methanol dehydration to formaldehyde

Theoretical analysis of the possibility of conjugating the reaction of formaldehyde formation via dehydrogenation of methanol with other initiating reactions is conducted; and advantages of using hydrogen peroxide vs. organic inductors are discussed. When hydrogen peroxide is used, the reaction reaches stationary condition almost immediately. It is demonstrated that the induction and the targeted reaction proceed with high selectivity towards formaldehyde