Efficiency of two-stage revision arthroplasty in management of periprosthetic knee and hip joint infection

This technique involves removal of implant components, debridement of the purulent focus and installation of a cement spacer which is subsequently replaced with a permanent implant after 3–9 months. Purpose To evaluate mid-term results of two-stage surgical treatment of patients with chronic periprosthetic infection of the knee and hip joints. Materials and methods Treatment outcomes of 172 patients with periprosthetic infection who underwent two-stage revision arthroplasty in the period from 2011 to 2015 were assessed. Among them, 113 patients developed infection after hip replacement and 59 patients had infected knee joint. The average follow-up period was 4 ± 1.58 years (range: 2 to 6 years). Results Out of 113 two-stage procedures of hip joint revision, 102 (90.2 %) cases showed an arrest of infection. Four (3.6 %) patients with recurrence of the purulent process underwent resection arthroplasty, another four (3.6 %) rejected to replace the spacer with an implant, and three (2.6 %) had a two-stage re-revision. Out of 60 (59 patients) procedures of a two-stage knee joint revision, infection was arrested in 50 (83.3 %) cases; eight (13.4 %) had recurrence and underwent knee arthrodesis. One (1.6 %) refused to replace a spacer for an implant, and one more (1.6 %) had a two-stage repeated revision. Conclusions Two-stage knee and hip revision arthroplasty using a cement spacer is an effective option for treatment of chronic periprosthetic infection. It provides infection control in 86.7 % (83.3 % for knee and 90.2 % for hip joints) of cases in the mid-term follow-up period up to 5 years. However, the rate of re-infection remains significant and reaches 13.3 % (9.8 % for hip and 16.7 % for knee joints)

Measuring Risk, Uncertainty and Valuation in Private Equity

I show that investors’ beliefs can explain the undervaluation of private equity (PE) funds. The value of PE funds, in accordance with finance principles, is determined by the expected cash flows discounted for time and risk. Therefore, the undervaluation may stem from either an incorrect stochastic discount factor (SDF) or a discrepancy between investors’ beliefs and the true distribution of cash flows. I propose an estimation method based on Empirical Likelihood (EL) to back out investors’ beliefs from funds’ cash flows. I validate estimated beliefs using investors’ sentiment surveys. I find that investors’ pessimism about PE cash flows and overoptimism about public market cash flows, rather than SDF misspecification, offer a potential explanation for the undervaluation of PE funds.9. Industry, innovation and infrastructur

Yaroslavl Aviation Cadets in Enemy Captivity (1942–1945)

The article is devoted to the analysis of the German and Romanian captivity of the cadets of the Yaroslavl Military Aviation School of Fast Bombardiers. There is no special research devoted to this group of prisoners of war in Russian and foreign historiography. The author has determined the time, place, and circumstances of taking the cadets captive; counted their number; found out the location of the camps where they were held. Based on sources of personal origin, the author has established survival strategies in difficult conditions of captivity, forms of resistance, the fate of cadets after their release as well as the names and dates of death of some cadets who died in captivity. The author concludes that Yaroslavl cadets differed from the vast majority of Soviet prisoners of war in their level of education and intelligence, unconditional adherence to communist ideology, good physical fitness, and a sense of camaraderie. They were captured as a result of the defeats of the Red Army in the battles of May–July 1942 at the Crimean and Southern fronts. Like other Soviet prisoners of war, Yaroslavl cadets became victims of the Nazi genocide. Some of them died during the first months in captivity of starvation and diseases caused by it, targeted executions, and suicides. Some improvements in nutrition and accommodation of Soviet prisoners of war, made by the Nazis in order to maximize the use of their labor, increased the cadets’ chances for survival. They spent more than two years in Romanian captivity, and almost three years in German captivity. Maintaining friendly relations with former co-servicemen and other prisoners of war turned out to be a successful survival strategy for the captured Yaroslavl cadets. Along with this, they resorted to concealing their military rank and the presence of a special military education from the enemy. The main forms of anti-fascist resistance of cadets were sabotage at workplaces, escapes, and the continuation of armed struggle with the enemy in Soviet and foreign partisan detachments. Like other Soviet prisoners of war, they were subjected to checks by Soviet security agencies after their release and then tried to prove their loyalty to the Motherland on the war fronts. Nevertheless, for decades, the fact of having been held captive created obstacles to continuing education, career growth, and normal life

Analysis of electric consumption: a study in the excavation area of the modern coal mine

The growth in the power supply of coal mines over the past decades has had a significant impact on their power consumption. The use of outdated materials for assessing the coal mine energy characteristics may lead to large calculation errors. At the same time, the problem of reducing the energy intensity of coal mining does not lose its relevance. However, in order to achieve it, it is necessary to take into account the current level of development of the mechanized complex of excavation areas. The widespread introduction of SCADA systems and the development of methods for big data processing makes it possible to collect large arrays of measurements and study the power consumption of mining equipment. In this paper, on the basis of extensive arrays of electrical load measurements and technological parameters, a statistical analysis of the load of a modern Eickhoff SL 900 longwall shearer of the Kuzbass coal mine is carried out

Formation of normative-methodical maintenance of quality and safety of campsites

Organization of campsites construction for auto tourists in Russia is an effective means of ensuring their rest and sleep during travel. Formation of normative and methodological support of campsites fire safety should take into account not only security, but also meet consumers' motivation to visit them. The authors examine conditions and requirements for the infrastructure of campsites and their localization, as well as methods of fire risk assessment in camping. They propose camping localization techniques and expert evaluation of fire risk in them

Application of Multi-Criteria Decision Analysis for Choice Geokhods Cutting Head

The article deals with the choice of cutterheads for Geokhod in the early development stages. Early development stages are characterized by the lack of quantitative characteristics, such as cutting forces, weight, feed forces, etc. In this case, the choice is made on the accordance of the cutterheads with the requirements for them. Under such conditions were determined the most appropriate method of multi-criteria analysis for the choice of the cutterheads – “ELECTRE III”. The results of the use of this method are established the most fully meet the requirements cutter heads: a rotary, drum, and head with fixed heads

Formation of normative-methodical maintenance of quality and safety of campsites

Organization of campsites construction for auto tourists in Russia is an effective means of ensuring their rest and sleep during travel. Formation of normative and methodological support of campsites fire safety should take into account not only security, but also meet consumers' motivation to visit them. The authors examine conditions and requirements for the infrastructure of campsites and their localization, as well as methods of fire risk assessment in camping. They propose camping localization techniques and expert evaluation of fire risk in them

Analysis of the reasons for the accelerated failure of oil pipelines in the regions of the Far North and Siberia

From about the time trends of development of oil gas complex of the country requires reassess the reliability and durability of pipelines for various purposes. The reason for this trend is the gradual displacement of the producing provinces towards regions with extremely low climatic temperatures, difficult natural conditions, and highly aggressive components of the oil production. Analysis of the reasons for the accelerated destruction of pipes in the northern regions of the country made it possible to identify two main causes of failure. This is the development of corrosion- mechanical defects and insufficient cold resistance and crack resistance of materials at low climatic temperatures. The paper analyzes the role of non-metallic inclusions in increased defectiveness of steel X70 pipes, an analysis of the influence of the microstructure and non-metallic inclusions of operation the pipes in cold climate

Investigating the influence of temperature on the selection of criteria for evaluating the propensity of tube steels to corrosion cracking at low loading speeds

The paper studies how temperature within the range of 20-80°C influences the destruction of tube steels in environments containing hydrogen sulfide and carbon dioxide. The tensile tests diagrams of tube steels with increasing temperature in hydrogen sulfide and carbon dioxide are analyzed. It is shown that increasing temperature affects the tendency of tube steels towards corrosion cracking. The criterion for evaluating the tendency towards corrosion cracking at increasing temperature does not change qualitatively and represents stress and relative deformation observed when a specimen is destroyed