BACKGROUND
: Precise localization of abnormal parathyroid glands is important for a successful surgery for primary hyperparathyroidism (PHPT). While a large number of patients can be successfully ...treated with the focused parathyroidectomy, there is a considerable rate of the persistent PHPT mostly because of undetected multiglandular disease (MGD).
AIM
: The aim of the study was to evaluate the meaning of preoperative visualization data for planning the surgery for patients with PHPT.
MATERIALS AND METHODS
: The study was conducted at SPBU Hospital in 2017-2018. 810 patients who underwent a primary surgery for PHPT were included in the study. Preoperative imaging results were investigated and multivariative logistic regressions were calculated to assess the predictive values of preoperative data. The rate of cases with persistent disease and cases with MGD were compared between patients with different results of preoperative data.
RESULTS
: Age, sex, body mass index, negative results of preoperative US, MIBI and 4D CT were not independently associated with the higher risk of multiglandular disease. The larger number of performed preoperative visualization studies were associated with the higher risk of persistence. 37% cases of MGD were not identified preoperatively. There were 7 cases with previously unsuspected second adenomas found only due to bilateral neck exploration.
CONCLUSION
: Any combination of preoperative visualization modalities was not able to rule out the MGD reliably. Efficacy of surgical treatment was not associated with the higher number of preoperative studies. Bilateral neck exploration may decrease the rate of the persistent hyperparathyroidism improving the identification of multiglandular disease.
B
ACKGROUND:
For a comprehensive assessment of the effect of surgery in patients with primary hyperparathyroidism (PHPT), as well as for monitoring the condition of patients after treatment, it ...sounds reasonable to evaluate quality of life (QoL) and symptoms in PHPT patients before and after surgery.
AIM:
The aim of this study was to assess changes in the QoL and symptoms in patients with PHPT after surgery.
MA
TERIALS
AND METHODS:
During prospective observational study, patients filled out QoL questionnaires and evaluated the presence and severity of their symptoms prior to parathyroidectomy (PTE) and 3, 12 months after surgery. Statistical analysis included the following methods: Student’s t-test or Wilcoxon’s non-parametric test, the generalized estimating equations (GEE), correlation analysis, χ2 and McNemar tests.
RESULTS:
The study included 72 patients (mean age 52 years, 97.2% female) with symptomatic (68.1%) and asymptomatic (31.9%) PHPT. Before surgery patients with PHPT exhibited significantly decreased role functioning, physical and social well-being, and vitality. Half of PHPT patients experienced moderate-to-severe symptoms such as weakness, fatigue, loss of concentration, mood changes, as well as joint and bone pain; the association between symptoms experienced and the extent of QoL impairment before surgery was shown. Three months after PTE improvement in both physical and psychological components of QoL was shown. Positive QoL changes were demonstrated in patients with both symptomatic and asymptomatic PHPT and they preserved for 12 months after surgery. Also within 12 months after PTE significant decrease in PHPT-associated symptoms such as weakness, fatigue, loss of concentration and mood changes was found.
CONCLUSION:
The results obtained demonstrate efficacy of PTE from the patient’s perspective and confirm the value of QoL assessment in PHPT patients in management of this patients’ population both for decision making and for evaluation of benefits of surgery and the degree of recovery of patients at long term follow-up.
Development of a new generation of composite with unique thermal properties is an important task in the fields of science and technology where material is operated at high temperatures and exposure ...to a short-wave radiation. Recent studies show that carbon nanomaterials (fullerenes and carbon nanotubes) could improve the thermal, radiation and thermal-oxidative stability of the polymer matrix. In this article the development of a new heat resistant composite based on elastomer and carbon nanotubes (CNT) was performed and physicochemical properties of final product were evaluated.
The characteristics of thermolysis of graft copolymers of polycaproamide and polyacrylonitrile of fibrous structure were investigated. The effect of the products of thermal oxidation of the graft ...copolymer on cross-linking of its thermoplastic polycaproamide component was demonstrated. It was found that the thermochemical transformations of the graft copolymer of polycaproamide and polyacrylonitrile in conditions of thermal oxidation cause formation of a structure of the polymer that ensures a high yield of carbonized residue in a wide range of temperatures.
The article analyzes the methods of removing uncertainty in conditions of insufficient information for making effective management decisions in complex organizational systems. In such tasks, the ...choice of an effective solution depends on the state of the external environment of the study and implies the use of a number of methods or mathematical models for solving multi-criteria problems. The main methods used in cases of occurrence of a situation of uncertainty due to insufficient information are the a priori ranking methods and multiple regression analysis. However, methods based on expert judgment have a significant degree of subjectivism, and methods formed on the experimental basis and mathematical planning of research are laborious and generate uncertainty with a large number of objects or elements involved in the situation. An alternative to the above is the method of zoning, which implies dividing the set of possible states of the research environment (nature) into subsets of the dominance of individual actions. The zoning operation is an inverse parametric linear programming problem. Consequently, for solving problems in conditions of insufficient information, one can use vector optimization methods.
In order to successfully accomplish the tasks of digitalizing control processes in the road complex integrated into a focused process, new generations of control systems - intelligent control systems ...- are being actively developed today. Intelligent control systems should be able to independently develop a goal, implement the decision-making process for an action, provide the necessary set of functions to achieve a goal, predict the values of system indicators as a result of actions and compare them with real data, providing feedback in the system and adjusting the control procedure. Currently, the methodological basis for making management decisions in control systems is the concept of scenarios based on the theory of expert assessments. The main disadvantage of this approach is the inability of the system to gradually adapt to changes in input information without completely reworking the structure of the initial requirements. For effective implementation of this task, it is necessary to develop a decision-making methodology in control systems based on formal logical methods of decision theory, namely, analytical methods for obtaining many effective plans, which should allow us to build algorithms that provide optimal solutions when implementing applied management tasks while having minimal information about the conditions of the research object.
The extensive development of the structures of the automobile-road complex requires optimization of the processes of their integration into the regional and global transport infrastructure. In order ...to effectively manage unstable traffic flows, automated control systems are developed that use complex algorithms based on the principles of artificial intelligence. The basis of this approach is the concept of transferring the concept of a control object from a generalized or aggregate traffic stream to a separate control element: a separate vehicle, a separate passenger, a separate consignment. The completed management process in the system of the road complex, which meets the current level of development of scientific and technological progress and productive forces, requires the use of digital object-oriented management models based on the creation of a unified communication and computer network for managing information flows as well as the development and application of control models physical objects of movement in the transport network, determining the optimal trajectory of movement of the latter. To form a control system based on object-oriented models, it is necessary to develop specialized analytical methods for multi-criteria evaluation of possible options. It is of fundamental importance that the developed methods can investigate the field of probabilities of changes in informational situations of the environment and are applicable to factors of any degree of uncertainty.
The authors analyze the propulsion of the planing hulls of the various small-class amphibious vehicles. The magnitude of the resistance forces depending on the movement speed is determined ...experimentally. For the correct formulation of experiments and their results, the study of various models of the planing small-class amphibious vehicles must comply with the dynamic similarity of the viscous friction and gravity forces. To compare planning effect provided by the design features of various amphibious models a relative measure of the hydrodynamic qualities or its inverse value can be used. In this article, numerical simulation by means of software complex is conducted to determine the hydrodynamic properties of the different planing small-class amphibious models. To verify the adequacy and accuracy of the generated numerical model, a comparison of the computer simulation results with the data of the full-scale experiment is used. Propulsion performance is compared for amphibious models with different hull contours and additional equipment.
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