The Concept of a Research Reactor of Small Power for Isotope Processing

The concept of a low-power research reactor for the production of radioisotopes is proposed, the results of calculations of the neutron-physical parameters of the core are presented, which can be used to substantiate the claimed reactor characteristics. In this article, the characteristics of the core of a research reactor of low power is substantiated, the main purpose of which is the production of radioisotope products for medical purposes. Nuclear medicine is one of the most advanced and demanded in the world of modern high-tech medicine, based on the using of atomic nucleus properties. As a rule, atoms with unstable nuclei are radionuclides. The reactor method of radionuclide production allows obtaining large quantities of radioisotope products at a relatively low price, but the reactor base is currently rather limited.     Keywords: radioisotope products, research reactors, neutron-physical characteristic

Hyperhomocysteinemia and functional state of endothelium in patients with peripheral artery disease with arterial reconstructions

АРТЕРИОСКЛЕРОЗ ОБЛИТЕРИРУЮЩИЙАОРТОПОДВЗДОШНЫЙ СЕГМЕНТБЕДРЕННО-ПОДКОЛЕННЫЙ СЕГМЕНТХИРУРГИЧЕСКИЕ ОПЕРАЦИИ ВОССТАНОВИТЕЛЬНЫЕ; РЕКОНСТРУКТИВНЫЕ ХИРУРГИЧЕСКИЕ ОПЕРАЦИИРЕНТГЕНОЭНДОВАСКУЛЯРНЫЕ ВМЕШАТЕЛЬСТВАГОМОЦИСТЕИНЭНДОТЕЛИАЛЬНАЯ ДИСФУНКЦИЯЦель. Изучить взаимоотношения гомоцистеина и маркеров функционального состояния эндотелия у пациентов с облитерирующим атеросклерозом при операциях на аорте и артериях нижних конечностей. Материал и методы. В исследование вошли 68 пациентов с облитерирующим атеросклерозом нижних конечностей, средний возраст 57,8±7,3 года, со IIБ-III степенью хронической артериальной недостаточности по R. Fontaine-А. В. Покровскому, распределенные на три группы: в I группе выполнено бедренно-подколенное шунтирование (n=32), во II – аорто-бедренное шунтирование (n=20), в III – рентгенэдоваскулярная ангиопластика и стентирование подвздошных артерий (n=16). Проведен корреляционный анализ между содержанием гомоцистеина и маркерами функционального состояния эндотелия: окисленными липопротеинами низкой плотности (окисленными ЛПНП), молекулой адгезии сосудистого эндотелия 1 типа (sVCAM-1), ингибитором тканевого активатора плазминогена 1 типа (PAI-1), тканевым активатором плазминогена (t-PA), Аннексином V в системном и местном кровотоке до операции и после артериальных реконструкций. Результаты. Установлены корреляционные взаимосвязи между гомоцистеином и окисленными ЛПНП как в системном кровотоке, так и в пораженной конечности, эта ассоциация сохранялась после реконструктивного вмешательства, была наиболее значимой в местном кровотоке после бедренно-подколенного шунтирования. Отмечена дооперационная положительная корреляция системного уровня гомоцистеина и sVCAM-1 в I группе. Показано влияние гомоцистеина на нарушение фибринолитической функции эндотелия, на что указывали прямые корреляционные взаимосвязи между гомоцистеином и PAI-1 в системном кровотоке и в пораженной конечности, сохраняющиеся после открытых реконструкций. Выявлены значимые связи между гомоцистеином и уровнем Аннексина V преимущественно в группе пациентов с поражением бедренно-подколенного артериального сегмента. Заключение. Гипергомоцистеинемия вносит свой значимый вклад в нарушение функционального состояния эндотелия, оказывая влияние на апоптоз, активацию атерогенных ЛПНП, прокоагулянтный потенциал, сохраняющиеся и после артериальных реконструкций как в системном, так и в местном кровотоке.Objective. To study the relationship between homocysteine and markers of the functional state of the endothelium in patients with obliterating atherosclerosis in operations on the aorta and arteries of the lower limbs. Methods. The study included 68 patients with peripheral artery disease, the average age was 57.8±7.3 years, with II B – III degree of chronic arterial insufficiency according to R. Fontaine-A. V. Pokrovsky, who were divided into three groups: I group underwent the femoro-popliteal bypass (n=32), II – the aorto-femoral bypass (n=20), III – x-ray endovascular angioplasty and stenting of the iliac arteries (n=16). A correlation analysis was made between the content of homocysteine and the markers of the endothelium functional state of: the oxidized low-density lipoproteins (oxidized LDL), a molecule of adhesion of the vascular endothelium type 1 (sVCAM-1), the tissue type 1 plasminogen activator inhibitor (PAI-1), the tissue plasminogen activator (t-PA), Annexin V in the systemic and local bloodstream prior to surgery and after the arterial reconstructions. Results. Correlation relationships between homocysteine and oxidized LDL were established both in the systemic blood flow and the affected limb, this association persisted after the reconstructive intervention, the most significant in the local bloodstream after femoro-popliteal bypass surgery. Preoperative positive correlation of the systemic level of homocysteine and sVCAM-1 in group I was marked. The effect of homocysteine on the fibrinolytic function of the endothelium was shown, as indicated by the direct correlation between homocysteine and PAI-1 in the systemic blood flow and in the affected limb, which persist after open reconstructions. Significant links between homocysteine and the level of Annexin V were revealed in the group of patients with the lesion of the femoro-popliteal arterial segment. Conclusions. Hyperhomocysteinemia contributes significantly to the disturbance of the endothelium functional state, affecting apoptosis, the activation of atherogenic LDL, and the procoagulant potential, which persist even after arterial reconstructions both in the systemic and local bloodstream

The experience of neural network prediction of the need for surgical treatment in patients with the diseases of hepatopancreatoduodenal zone

Aim. Using multilayer perceptron artificial neural network, to develop a mathematical model for predicting the need for surgical intervention in patients admitted for hepatopancreatoduodenal zone diseases and to assess the capabilities for its clinical application. Methods. The study was performed using the data of 488 patients with peptic ulcer, cholecystitis or pancreatitis, analyzed using multilayer perceptron artificial neural network, trained to distinguish vectors of data on risk factors of patients who did or did not require surgical intervention during current hospitalization. Results. Patients in the training sample who had required surgical intervention during hospitalization were different from patients who had undergone conservative treatment by such characteristics as gender, age, duration of the disease, state on admission, and the structure of risk factors. The acquired data made it possible to train the artificial neural network. The ROC analysis of the mathematical model demonstrated the area under the curve (AUC) equal to 0.880 for the training group (n=385) and 0.739 for the clinical approbation group (n=103). Conclusion. The AUC indicators of the created model can be characterized as very good in terms of predicting the need for surgical treatment in the training group and good for the clinical approbation group: sensitivity and specificity of the model exceed 80% in the training group and are highest in patients with peptic ulcer disease; in the clinical approbation group these parameters were lower as expected, however, remained at the level of 60-70%

Influence of the composition on the thermoelectric and electro-physical properties of Ge-Sb-Te thin films for phase change memory application

Influence of the composition variation along the quasi-binary line GeTe-Sb2Te3 on the thermoelectric and electro-physical properties of thin films was investigated. GST amorphous thin films have high Seebeck coefficients, which drops nearly on the order of magnitude after the crystallization. Temperature dependences of the resistivities were studied, and it was determined that crystallization temperature increases with moving along the quasi-binary line GeTe-Sb2Te3 from GeSb4Te7 to GeSb2Te4, and then to Ge2Sb2Te5, while the phase transition temperature range decreases. Current-voltage characteristics of amorphous thin films have three voltage ranges with different dependencies due to the different mechanisms of charge carrier transport

Studies of ticks of the genus Dermacentor (Acari; Ixodidae) on the natural occurrence of tularemia pathogen in the conditions of the Central Pre-Caucasian region

The purpose of the research is the assessment of the Francisella tularensis occurrence in nature in ticks of the genus Dermacentor; understanding the physiological age in terms of tick infection with tularemia pathogen.Materials and methods. For the period from 2015 to 2019, we examined 8449 specimens of Dermacentor marginatus (916 pools), 8674 specimens of D. reticulatus (705 pools), and 109 specimens of D. niveus (40 pools) for tularemia infection. To assess the dependence of tularemia pathogen found in ticks of different physiological ages, we examined 2440 specimens of D. marginatus (360 pools), and 3349 specimens of D. reticulatus (412 pools) for the period from 2016 to 2019. Studies of ixodid ticks infected with tularemia pathogen were performed by the Natural Focal Infection Laboratory of the Stavropol Anti-Plague Institute. Pools of ixodid ticks were examined for the pathogen DNA of tularemia using reagent kits for identifying Francisella tularensis DNA by polymerase chain reaction with fluorescence hybridization of results recorded in real time.Results and discussion. The infection rate of the tularemia pathogen in ticks in the Central Pre-Caucasian region ranged from 0.044–1.127% in D. marginatus and 0.035–1.455% in D. reticulatus in different years. The greatest number of F. tularensis was isolated from the III physiological age ticks. For D. reticulatus ticks, no statistically significant dependence of the detected tularemia pathogen on physiological age was found

In Vivo Simulation of the Purulent Peritonitis

Currently, purulent-inflammatory diseases of the abdominal organs are the prevalent causes of complications and mortality. Treatment of these diseases complicated by peritonitis is one of the urgent problems in modern clinical medicine. Experiment is important for testing new treatment methods. This article provides a systematic analysis of the current in vivo models of the purulent peritonitis, which are used to test the options for surgical treatment and combinations of antibacterial drugs. We describe the most common models as well as rare simulations of specific peritonitis. It should be noted that despite the wide use of minimally invasive techniques, the literature has few reports on simulation of peritonitis through the laparoscopic approach

Hernia or hernia Defect? Experimental herniology Models in Laboratory Animals

Hernias of the anterior abdominal wall remain one of the most common surgery pathologies. There is no unified approach to modeling anterior abdominal wall hernias in the world scientific community. In order to systematize the available knowledge in this field and to contribute to the formation of a unified idea of how to create a hernia model in a laboratory animal, it seems logical to study the accumulated experience of researchers in the field of experimental herniology. We found out that hernia defects generally modeled on male laboratory rats. To understand the tissue reaction to the prosthetic material a fenestration was performed in the anterior abdominal wall (including peritoneum) except for the skin and subcutaneous fat. A replacement or prosthetic material tailored to the fenestration was sutured end-to-end into the abdominal wall. We chose laboratory rats because they are easy to take care of and cheaper than larger laboratory animals

Studying the influence of Solcoseryl drug and vitamin C on the inflammatory reaction and proliferation of fibroblastic cells in the filed of polypropylene endoprosthesis implantation

The aim of investigation was to study the effect of Solcoseryl and Vitamin C in a collagen-stimulating coating of hernioendoprosthesis on a morphological picture in anterior abdominal wall plastic surger