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BACKGROUND & AIMS In patients with compensated advanced chronic liver disease (cACLD), the severity of portal hypertension (PH) determines the risk of decompensation. Invasive measurement of the hepatic venous pressure gradient (HVPG) is the diagnostic gold standard for PH. We evaluated the utility of machine learning models (MLMs) based on standard laboratory parameters to predict the severity of PH in cACLD patients. METHODS A detailed laboratory workup of cACLD patients recruited from the VIENNA cohort (NCT03267615) was utilised to predict clinically significant portal hypertension (CSPH, i.e., HVPG≥10mmHg) and severe PH (i.e. HVPG≥16mmHg). The MLMs were then evaluated in individual external datasets and optimised in the merged cohort. RESULTS Among 1232 cACLD patients, the CSPH and severe PH prevalence in VIENNA (n = 163, 67.4%/35.0%) and the validation cohort (n = 1069, 70.3%/34.7%) were similar. The MLMs were based on 3 (3P; platelets, bilirubin, INR) or 5 (5P; +cholinesterase, +gamma-glutamyl transferase, +aPTT replacing INR) laboratory parameters. The MLMs performed robustly in VIENNA with best AUROCs for CSPH by 5P-MLM: 0.813 and for severe PH by 5P-MLM: 0.887 and compared favourably to liver stiffness measurement (AUROC: 0.808). Their performance in external validation datasets was heterogeneous (AUROCs 0.589-0.887). Training on the merged cohort optimized the MLM performance for CSPH (AUROCs: 3P: 0.775, 5P: 0.789) and for severe PH (AUROCs 3P: 0.737, 5P: 0.828). CONCLUSIONS Internally-trained MLMs reliably predicted PH severity in the VIENNA cACLD cohort but exhibited heterogeneous results on external validation. The proposed 3P/5P online tool can reliably identify patients with CSPH or severe PH, thus, at risk for hepatic decompensation. LAY SUMMARY The gold standard for diagnosing portal hypertension is the invasive measurement of the hepatic venous pressure gradient. In this work, we selected the most suitable, widely available laboratory parameters for machine learning models to predict the likelihood and severity of portal hypertension in patients with compensated cirrhosis. This will aid in the identification of patients who are at the highest risk for subsequent hepatic decompensation.

The cold chain supply of donor organs for transplantation has been an integral part of the delivery of transplant clinical services over the past five decades. Within the technologies used for this, hypothermic machine perfusion (HMP) was a concept, which was attractive to maintain organs under optimal conditions outside the body, and many early research studies on HMP were reported. However, it took the arrival of important new concepts to ensure that HMP was logistically feasible and valuable from an organ physiology perspective within the clinical pathways. This review provides details of the current status of HMP across the range of organs transplanted in the clinic, and discusses what new areas might benefit from applying HMP in coming years. In conclusion, HMP is now being used more frequently for clinical organ preservation in a variety of settings. As new therapies such as cell or gene therapy become more common, HMP will continue to play an important facilitator role for optimising organs in the donor pathway.

Contemporary tendencies relentlessly dictate the conditions for the appearance of a more qualitative, reliable and comfortable elevator chain for the rolling stock of a vertical motion. At the same time, the issues of energy saving and cost-effective use of resources gain currency against the background of rising prices for energy carriers and market prices for various elements that play an essential role in the availability of many electromechanical systems. Unfortunately, attention was paid to the availability of above problems in the elevator sector when the majority of the elevators (about 60% of them) outlived their technical service life that ensured the reliable operation. As a matter of fact, an amazingly important issue is relating to the embedment of reliable, durable and economically substantiated components of electromechanical systems into contemporary Ukrainian elevators. The purpose of the research done was to define the main parameters and performances of the asynchronous elevator motor of an ADB180M6 type. The motor is powered from the industrial network of 50 Hz and the frequency converter with the frequency of 50Hz and 16.6 Hz. This scientific paper uses the methods of physical investigations. The elevator motor test data satisfy the reliability parameters that make any elevator user feel comfortable. The main measurement data obtained for the engine No43886 of an ADB180M6 type powered from the frequency converter “Altivar” of 22kW with the motor speed of 910 rpm and 289 rpm satisfy the requirements of the regulatory documentation. The noise level is within satisfactory margins.

Liver fibrosis is the static and main (70%-80%) component of portal hypertension (PH). We investigated dynamic components of PH by a three-dimensional analysis based on correlation of hepatic collagen proportionate area (CPA) with portal pressure (PP) in animals or HVPG in patients.Different animal models (bile duct ligation: n = 31, carbon tetrachloride: n = 12, thioacetamide: n = 12, choline-deficient high-fat diet: n = 12) and patients with a confirmed single etiology of cholestatic (primary biliary cholangitis/primary sclerosing cholangitis: n = 16), alcohol-associated (n = 22), and metabolic (NASH: n = 19) liver disease underwent CPA quantification on liver specimens/biopsies. Based on CPA-to-PP/HVPG correlation, potential dynamic components were identified in subgroups of animals/patients with lower-than-expected and higher-than-expected PP/HVPG. Dynamic PH components were validated in a patient cohort (n = 245) using liver stiffness measurement (LSM) instead of CPA. CPA significantly correlated with PP in animal models (Rho = 0.531; p0.001) and HVPG in patients (Rho = 0.439; p0.001). Correlation of CPA with PP/HVPG varied across different animal models and etiologies in patients. In models, severity of hyperdynamic circulation and specific fibrosis pattern (portal fibrosis: p = 0.02; septa width: p = 0.03) were associated with PH severity. In patients, hyperdynamic circulation (p = 0.04), vascular dysfunction/angiogenesis (VWF-Ag: p = 0.03; soluble vascular endothelial growth factor receptor 1: p = 0.03), and bile acids (p = 0.04) were dynamic modulators of PH. The LSM-HVPG validation cohort confirmed these and also indicated IL-6 (p = 0.008) and hyaluronic acid (HA: p0.001) as dynamic PH components.The relative contribution of "static" fibrosis on PH severity varies by type of liver injury. Next to hyperdynamic circulation, increased bile acids, VWF-Ag, IL-6, and HA seem to indicate a pronounced dynamic component of PH in patients.

Today in the world there are many electric propulsion systems based on the different types of thrusters. Most of them used gaseous propellent. Typical Electric propulsion system (EPS) consists of following main subsystems: the electric propulsion thruster that creates thrust; the power-processing and control unit which provides energy to all subsystems; the storage and feed system that performs functions of storing working substance in the tank and supplying the required amount of working substance to the thruster; Solenoid valve is a part of storage and feed systems. The feed system is an essential part of any electric propulsion system. The life cycle of the feed system is largely determined by lifetime of the valves and the amount of working substance in tank. Whereas the amount of working substance is selected based on the requirements for each specific mission valve parameters must be satisfying for various missions. Accordingly, the valves must have low power consumption, high reliability with a long lifetime (more than 106 cycles), low weight and dimensions. Solenoid valve is an electromechanical device that consists of moving part controlled by an electromagnet. Movement of the movable element and the seal are key parts of valve reliability. Presented solenoid valve design uses two membranes, which perform the function of centering the moving element and with the spring provide the required closing speed and the seal of the valve. The paper presents the problem of selecting critical elements that affect the solenoid valve's performance, procedure and test results required for the qualification of space equipment. Manufactured valve was successfully tested (vibration testing, response time testing with inlet pressure change, response time testing at different operating voltages, dependence of the valve actuation current on the operating voltage, temperature testing, lifetime tests) separately and as part of XFS according to the ECSS standards. As well as the successful implementation of presented valve into the flight xenon feed system for electric propulsion.

Dental pulp stem cells (DPSCs) from human third molar tooth germ (wisdom tooth) were isolated using a collagenase based enzymatic method, the obtained cells were analyzed as for morphology in monolayer culture, immunophenotype, proliferation and differentiation potential before and after cryopreservation. In this study, we showed that based on morphological features, surface markers profile and differentiation potential, the isolated DPSCs corresponded to multipotent mesenchymal stromal cells. DPSCs cryopreservation by slow cooling (1 °С / min) down to –80°C with subsequent immersion into liquid nitrogen in cryoprotectant-free culture medium led to cell death. Cryopreservation using the same protocol in the presence of 10% dimethyl sulfoxide (DMSO) and 20% serum ensured (82 ± 6)% cell viability; while metabolic and proliferative activity, as well as the ability to differentiate into the osteo- and adipogenic lineages of cryopreserved DPSCs were similar to their non-cryopreserved counterparts. Probl Cryobiol Cryomed 2021; 31(1): 058–069

A mathematical model has been built of the subway car on two double-axle bogies with an axial characteristic of 20–20, whose spring suspension’s central link is equipped with springs and electromechanical dampers. A special feature of the model is its integration of such components as 17 differential equations of the second order, which describe the operation of the mechanical part «carriage-rail track», as well as 8 differential equations of the first order that describe the operation of 4 electromechanical shock absorbers. The model is complemented with three polynomials of orders 32 and 63 describing the state of the magnetic field of electromechanical shock absorbers and their electromagnetic force, as well as 4 algebraic coupling equations. The mathematical model of the «carriage-rail track» system equipped with electromechanical shock absorbers takes into consideration the following components: –the longitudinal and transverse oscillations by wheelsets of the car bogies and body; –the parameters of a rail track; –the electromagnetic features of electric shock absorbers; –the excitation arising from a track irregularity; –the path parameters, as well as the properties of other elements in a spring suspension. This paper reports a study into the operation of a subway car’s spring suspension that travels over a track with a sinusoidal irregularity. The study has established that the electromechanical processes in electric shock absorbers can be divided into three parts. The oscillation free mechanical components, free components, and the forced electromagnetic components. The duration of action, the amplitudes, and nature of the oscillations’ components have been determined. The oscillation amplitude varies considerably with the increased speed: from 0.01A and 2V at 40km/h up to 0.9A and 115V at 100km/h. The oscillations are harmonious. The frequency of oscillations corresponds to the frequency of the track irregularity. The electric power of the electric shock absorber increases from 0.018W at 40km/h to 98W at 100km/h

Portal hypertension (PH)-associated splenomegaly is caused by portal venous congestion and splanchnic hyperemia. This can trigger hypersplenism, which favors the development of cytopenia. We investigated the time-dependent impact of splenectomy on portal pressure and blood cell counts in animal models of non-cirrhotic and cirrhotic PH.Ninety-six rats underwent either partial portal vein ligation (PPVL), bile duct ligation (BDL), or sham operation (SO), with subgroups undergoing additional splenectomy. Portal pressure, mean arterial pressure, heart rate, blood cell counts and hemoglobin concentrations were evaluated throughout 5 weeks following surgery.Following PPVL or BDL surgery, the animals presented a progressive rise in portal pressure, paralleled by decreased mean arterial pressure and accelerated heart rate. Splenectomy curbed the development of PH in both models (PPVL: 16.25 vs. 17.93 ​mmHg, p ​= ​0.083; BDL: 13.55 vs. 15.23 ​mmHg, p ​= ​0.028), increased mean arterial pressure (PPVL: +7%; BDL: +9%), and reduced heart rate (PPVL: -10%; BDL: -13%). Accordingly, splenectomized rats had lower von Willebrand factor plasma levels (PPVL: -22%; BDL: -25%). Splenectomy resulted in higher hemoglobin levels in PPVL (14.15 vs. 13.08 ​g/dL, p ​ ​0.001) and BDL (13.20 vs. 12.39 ​g/dL, p ​= ​0.097) animals, and significantly increased mean corpuscular hemoglobin concentrations (PPVL: +9%; BDL: +15%). Thrombocytopenia only developed in the PPVL model and was alleviated in the splenectomized subgroup. Conversely, BDL rats presented with thrombocytosis, which was not affected by splenectomy.Splenectomy improves both cirrhotic and non-cirrhotic PH, and ameliorates the hyperdynamic circulation. Hypersplenism related anemia and thrombocytopenia were only significantly improved in the non-cirrhotic PH model.

Background Primary biliary cholangitis (PBC) may progress to cirrhosis and clinically significant portal hypertension (CSPH). This study assesses different features of CSPH and their distinct prognostic impact regarding decompensation and survival in patients with PBC. Methods Patients with PBC were identified during a database query of our digital patient reporting system. Results A total of 333 PBC patients (mean age 54.3 years, 86.8% females, median follow-up 5.8 years) were retrospectively assessed and 127 (38.1%) showed features of CSPH: 63 (18.9%) developed varices, 98 (29.4%) splenomegaly, 62 (18.6%) ascites and 20 (15.7%) experienced acute variceal bleeding. Splenomegaly, portosystemic collaterals and esophageal varices were associated with an increased 5-year (5Y) risk of decompensation (15.0%, 17.8% and 20.9%, respectively). Patients without advanced chronic liver disease (ACLD) had a similar 5Y-transplant free survival (TFS) (96.6%) compared to patients with compensated ACLD (cACLD) but without CSPH (96.9%). On the contrary, PBC patients with cACLD and CSPH (57.4%) or decompensated ACLD (dACLD) (36.4%) had significantly decreased 5Y survival rates. The combination of LSM Conclusion In PBC, features of CSPH may occur early and indicate an increased risk for subsequent decompensation and mortality. Hence, regular screening and on-time treatment for CSPH is crucial. Combining LSM and platelets serves as a valuable preliminary assessment, as LSM

A procedure has been devised for modeling the dynamic pro-cesses in the proposed structure of an electromechanical shock absorber. Such shock absorbers can recuperate a part of the energy of oscillations into electrical energy allowing the subsequent possibility to use it by rolling stock. The procedure is based on solving the Lagrange equation for the electromechanical system. The model’s features are as follows. The model takes the form of a Cauchy problem, thereby making it possible to use it when simulating the processes of shock absorber operation. Two generalized coordinates have been selected (the charge and displacement of the armature). The components of the Lagrange equation have been identified. Based on the results from magnetic field calculation and subsequent regression analysis, we have derived polynomial dependences of flux linkage derivatives for the current and linear displacement of an armature, which make it possible to identify a generalized mathematical model of the electromechanical shock absorber. The magnetic field calculations, performed by using a finite-element method, have allowed us to derive a digital model of the magnetic field of an electromechanical shock absorber. To obtain its continuous model, a regression analysis of discrete field models has been conducted. When choosing a structure for the approximating model, a possibility to analytically differentiate partial derivatives for all coordinates has been retained. Based on the results from modeling free oscillations, it was established that the maximum module value of current is 0.234 A, voltage – 52.9 V. The process of full damping of oscillations takes about 3 seconds over 4 cycles. Compared to the basic design, the amplitude of armature oscillations and its velocity dropped from 13 to 85 % over the first three cycles, indicating a greater efficiency of electromechanical shock absorber operation in comparison with a hydraulic one. The recuperated energy amounted to 3.3 J, and the scattered energy – 11.5 J. Для запропонованої конструкції електромеханічного амортизатору розроблено методику моделювання динамічних процесів. Такі амортизатори мають можливість рекуперувати частину енергії коливань в електричну енергію з подальшою можливістю її використання на рухомому складі. Методика основана на вирішенні рівняння Лагранжу для електромеханічної системи. Особливості моделі є наступними. Модель має вигляд задачі Коши, який спритний до вживання при моделювання процесів роботи амортизатору. Обрані дві узагальнені координати (заряд та переміщення якорю). Ідентифіковані складові частини рівняння Лагранжу. За результатами розрахунку магнітного поля і подальшого регресійного аналізу отримано поліноміальні залежності похідних потокозчеплення потоку і лінійному переміщенню якоря, які дають можливість ідентифікувати узагальнену математичну модель електромеханічного амортизатору. Проведені розрахунки магнітного поля методом скінчених елементів дозволили отримати цифрову модель магнітного поля електромеханічного амортизатору. Для отримання її безперервної моделі проведено регресійний аналізу дискретні моделі поля. Про виборі структури апроксимуючої моделі дотримана можливість аналітичного диференціювання часткових похідних по всіх координатах. За результатами моделювання вільних коливань встановлено, що максимальне по модулю значення струму складає 0,234 А, а напруги – 52,9 В. За близько 3 с. проходить процес повного погашення коливань за 4 періоду. Порівняно з базовою конструкцією амплітуда коливань ходу якоря та його швидкості знизилась від 13 до 85 % за перші три періоди, що свідчить про більшу ефективність роботи електромеханічного амортизатору в порівнянні з гідравлічним. Енергія, що рекуперовано, склала 3,3 Дж, а, що розсіяно – 11,5 Дж.

Ochenashko, O. V., Nikitchenko, Y. V., & Petrenko, O. Y. (2019). Multiple Injections of Cryopreserved Fetal Liver Cells to Ageing Rats Prevent Age-Related Antioxidant System Changes and Increase Lifespan. Problems of Cryobiology and Cryomedicine, 29(3), 221–236. In the present work, the possibility of using cryopreserved fetal liver cells (ÑFLC) as an anti-aging agent, assessing their effect on the prooxidant-antioxidant balance, the physiological parameters and the life span of aging rats was investigated. It has been established that the repeated administration of ÑFLC (every 3 months) to adult rats from 13 to 22 months of age, prevents changes in the prooxidant-antioxidant balance of the liver and blood that form in older animals by 25 months. Similar multiple injections of ÑFLC to old rats (from 23 months to the end of life) contribute to weight gain, hamper the reduction in the quality of the coat and prolong the life span of experimental rats by 100 days. The results of the work allow considering the transplantation of ÑFLC as a promising approach for correcting the age-related changes associated with the development of oxidative stress.

A procedure for determining basic estimation parameters has been devised for the proposed structure of the electromechanical shock absorber. The procedure is based on a simplified mathematical model for determining the electromagnetic and electromotive force for the electromechanical shock absorber. Feature of the model is taking into consideration the operational modes of permanent magnet based on the calculation of a magnetic circle. The model devised makes it possible to perform approximate calculation of the shock absorber operational modes and could be used for solving the problem on the optimization of parameters for an electric shock absorber. We have verified adequacy of the constructed simplified mathematical model by comparing the results from calculating the mechanical characteristic for a shock absorber based on the simplified procedure and those obtained using a finite element method in the axial-symmetrical statement of the problem. There is a good match between the results from calculations based on the simplified procedure and from modeling a magnetic field using the method of finite elements. We have determined the geometric relationships between the elements of the structure that ensure the optimal uniform magnetic load on the elements of the magnetic circuit. The problem on the conditional two-criteria optimization of parameters for the electromechanical shock absorber has been stated. We have chosen constraints that are divided into the three following categories. Constraints for a permanent magnet demagnetization that make it possible to maintain operability of the permanent magnet. Constraints for a current density, which ensures the thermal modes in the shock absorber operation. Constraints for assembly and constraints for the parameters of an optimization problem, which enable the arrangement of a structure within the running part of a carriage. It has been proposed to choose the reduced volume of a shock absorber as a criterion, which predetermines the cost of constructing a shock absorber, and its efficiency as a criterion, which predetermines the recuperated energy of oscillations. The parameters were convoluted to a single objective cost function; the weights were defined. We have chosen, as an optimization method, the combined method that includes a genetic algorithm at the preliminary stage of the search. At the final stage of an optimization procedure an optimum is refined by using the Nelder-Mead method. The result from solving the optimization problem on the shock absorber's parameters is the defined optimal geometric dimensions and the number of turns in the winding of the electromechanical shock absorber.

The methods of arm wrestling and the peculiarities of their implementation in the training process of training of cadets of military higher educational institutions of Ukraine are analyzed. It is proposed to implement these methods during physical training sessions by combining technical techniques and methods into a rational chain of motor activities. The interrelation and interdependence of the structure of movements and the level of development of physical qualities under the conditions of the use of methods of arm wrestling during the period of successive exercises on simulators and with partners during independent training by physical training is substantiated

Nuclear receptors are ligand-activated transcription factors that regulate gene expression of a variety of key molecular signals involved in liver fibrosis. The primary cellular driver of liver fibrogenesis is activated hepatic stellate cells. Different nuclear receptors regulate the hepatic expression of pro-inflammatory and pro-fibrogenic cytokines that promote the transformation of hepatic stellate cells into fibrogenic myofibroblasts. Importantly, nuclear receptors regulate gene expression circuits that promote hepatic fibrogenesis and/or allow liver fibrosis regression. In this review, we highlight the direct and indirect influence of nuclear receptors on liver fibrosis, with a focus on hepatic stellate cells, and discuss potential therapeutic effects of nuclear receptor modulation in regard to anti-fibrotic and anti-inflammatory effects. Further research on nuclear receptors-related signaling may lead to the clinical development of effective anti-fibrotic therapies for patients with liver disease.

A ballean is a set $X$ endowed with some family $\F$ of its subsets, called the balls, in such a way that $(X,\F)$ can be considered as an asymptotic counterpart of a uniform topological space. Given a cardinal $\kappa$, we define $\F$ using a natural order structure on $\kappa$. We characterize balleans up to coarse equivalence, give the criterions of metrizability and cellularity, calculate the basic cardinal invariant of these balleans. We conclude the paper with discussion of some special ultrafilters on cardinal balleans.

Let $G$ be a group and $X$ be a $G$-space. A subset $F$ of $X$ is called a kaleidoscopical configuration if there exists a surjective coloring $\chi:X\to Y$ such that the restriction of $\chi$ on each subset $gF$, $g\in G$ is a bijection. We give some constructions of kaleidoscopical configurations in an arbitrary $G$-space, develop some kaleidoscopical technique for Abelian groups (considered as $G$-spaces with the action $(g,x)\mapsto g+x$), and describe kaleidoscopical configurations in the cyclic groups of order $N=p^m$ or $N=p_1... p_k$ where $p$ is prime and $p_1,...,p_k$ are distinct primes. Let $G$ be a group and $X$ be a $G$-space. A subset $F$ of $X$ is called a kaleidoscopical configuration if there exists a coloring $\chi:X\rightarrow C$ such that the restriction of $\chi$ on each subset $gF$, $g\in G$, is a bijection. We present a construction (called the splitting construction) of kaleidoscopical configurations in an arbitrary $G$-space, reduce the problem of characterization of kaleidoscopical configurations in a finite Abelian group $G$ to a factorization of $G$ into two subsets, and describe all kaleidoscopical configurations in isometrically homogeneous ultrametric spaces with finite distance scale. Also we construct $2^c$ (unsplittable) kaleidoscopical configurations of cardinality continuum in the Euclidean space $R^n$., Comment: 11 pages