Value of abdominal ultrasound study in the evaluation of the liver parenchyma in potential related donors of liver fragments

A comprehensive examination, involving ultrasonography (US) in 55 potential related donors of liver fragments, revealed no signs of diffuse liver lesion (DLL) in 45 cases (Group A), these were found in 10 cases (Group B).Liver fragment taking surgery was performed in Group A patients 1–2 weeks after US. All the 45 patients in this group were found to have a normal US pattern of the liver, as verified by its histological studies in all the cases; all these patients had also a mass body index (MBI) of lower than 25 kg/m2 . In Group B, all the 10 patients had the US signs comparable with mild or moderate DLL (increased liver parenchymal echogenicity, worse visualization of the small branches of the intrahepatic veins and diaphragm, and altered patterns of blood flow in the right hepatic vein) generally concurrent with a higher MBI. After 3–4-month treatment to reduce weight (conditioning), the liver US pattern normalized in 9 of the 10 Group B patients; only one patient with a MBI of 31.6 kg/m2 preserved the signs of mild DLL (histological studies of liver biopsy specimens revealed 10% steatosis in this patient, 2 % steatosis in 2 female patients; this condition was absent in the other 7 patients). All the patients in Group B were also operated on 1–2 weeks after the last US. The recipients from Groups A and B donors had no posttransplantation parenchymal complications.US in the tints of a gray scale along with the determination of blood flow patterns in the hepatic veins rather significantly shows the normal liver in its potential donors and reduces the need for serial diagnostic liver biopsies and other instrumental studies

Purpuromycin: a new inhibitor of tRNA aminoacylation

Purpuromycin, an antibiotic produced by Actinoplanes ianthinogenes, had been reported previously to inhibit protein synthesis. In the present report, we demonstrate that the mechanism of action of this antibiotic is quite novel in that it binds with fairly high affinity to all tRNAs, inhibiting their acceptor capacity. Although more than one molecule of purpuromycin is bound to each tRNA molecule, the inhibitory activity of this antibiotic was found to be selective for the tRNA acceptor function; in fact, after the aminoacylation step, purpuromycin was found to affect none of the other tested functions of tRNA (interaction with the ribosomal P- and A-sites and interaction with translation factors). Accordingly, purpuromycin was found to inhibit protein synthesis only when translation depended on the aminoacylation of tRNA and not when the system was supplemented with pre-formed aminoacyl-tRNAs. Because purpuromycin did not interfere with the ATP-PPi exchange reaction of the synthetase or with the initial interaction of the enzyme with its tRNA substrate, the basis for the inhibition of aminoacylation is presumably the formation of a nonproductive synthetase-tRNA complex in the presence of purpuromycin in which the tRNA is unable to be charged with the corresponding amino acid

Purpuromycin: an antibiotic inhibiting tRNA aminoacylation.

Purpuromycin, an antibiotic produced by Actinoplanes ianthinogenes, had been reported previously to inhibit protein synthesis. In the present report, we demonstrate that the mechanism of action of this antibiotic is quite novel in that it binds with fairly high affinity to all tRNAs, inhibiting their acceptor capacity. Although more than one molecule of purpuromycin is bound to each tRNA molecule, the inhibitory activity of this antibiotic was found to be selective for the tRNA acceptor function; in fact, after the aminoacylation step, purpuromycin was found to affect none of the other tested functions of tRNA (interaction with the ribosomal P- and A-sites and interaction with translation factors). Accordingly, purpuromycin was found to inhibit protein synthesis only when translation depended on the aminoacylation of tRNA and not when the system was supplemented with pre-formed aminoacyl-tRNAs. Because purpuromycin did not interfere with the ATP-PPi exchange reaction of the synthetase or with the initial interaction of the enzyme with its tRNA substrate, the basis for the inhibition of aminoacylation is presumably the formation of a nonproductive synthetase-tRNA complex in the presence of purpuromycin in which the tRNA is unable to be charged with the corresponding amino acid

Application of the digital twin at NPP I&C system life cycle

Точная оценка архитектуры и характеристик АСУ ТП АЭС является сложной задачей для экспертов и инженеров. В работе рассматривается проблема разработки и применения цифрового двойника для оценки характеристик цифровой системы управления АЭС в течение ее жизненного цикла. Анализируются сценарии применения цифровых двойников на этапах жизненного цикла АСУ ТП АЭС, от проектирования до вывода её из эксплуатации. В работе рассматриваются и обобщаются моделируемые свойства, относящиесяк цифровым и физическим компонентам системы. Особое внимание уделяется сценариям использования цифрового двойника для повышения кибербезопасности АСУ ТП АЭС и управлению изменениями. В Работе описывается реализация цифрового двойника для реальной системы верхнего блочного уровня АЭС. The precise evaluation of the instrumentation and control (I&C) system design and characteristics is a challenge for experts and engineers. This paper considers the problem of the development and application of a digital twin to assess digital I&C system during it life cycle. We analyze the details of digital twin applications at different lifecycle stages from design to decommissioning. The work reviews and summarizes properties of models concerning the digital and physical components of a I&C system. The other issue of a I&C is increasing cybersecurity threat for NPP, so special attention is paid to the heterogeneous digital twin usage scenarios to improve I&C cybersecurity. The paper also details the digital twin’s implementation for a real upper-level control system of a nuclear power plant