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

Pharmacological effects of the synthetic analogue of the indolicidin on the regeneration of burn and cold wounds in the experiment

There were studied the effects of the use of the synthetic analogue of indolicidin 21 on the processes of regeneration of thermal wounds, the systemic inflammatory response, the functional activity of neutrophils and macrophages, lipid peroxidation processes for IIIA-B degree burns and II-III degree frostbites in rat

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

Multiplexing signals with twisted photons by a circular arc phased array

The theory of multiplexing electromagnetic signals by means of twisted photons generated by a uniform circular array is developed in the case when the receiving antenna represents an array of elements located on a circular arc. The notion of discrete twisted photons of the order $N$ is introduced and orthogonality of these modes modulo $N$ is established. Both paraxial and planar discrete twisted photons are considered. It is shown that in the simplest scenario a $K$ times decrease of the circular arc where the receiving array antenna is placed results in a $K$ times decrease of the number of independent information channels. In the more sophisticated approach, one can restore all $N\gg1$ independent information channels in receiving the signal by an array antenna with $N$ elements located on a circular arc with the central angle $2\pi/K$. However, this problem becomes rapidly ill-conditioned as one increases $K$. The method mitigating this issue is described. The estimates for the corresponding condition numbers are found.Comment: 15 pp., 3 fig

Magnetic force microscopy of atherosclerotic plaque.

In this work by methods of scanning probe microscopy, namely by atomic force microscopy and magnetic force microscopy the fragments of atherosclerotic plaque section of different nature were investigated. The fragments of atherosclerotic vessels with elements of immature plaque were taken during the coiled artery bypass surgery by alloprosthesis. As the result of investigation we found magnetically ordered phase of endogenous origin in the fragment of solid plaque of mixed structure. This phase is presents biogenic magnetic nanoparticles and their clusters with average size characteristic of 200-400 nm

Linear and nonlinear magneto-optical diffraction from one-dimensional periodic structures

Nonlinear magneto-optical diffraction from periodically structured samples has been studied using magnetization-induced second harmonic generation (MSHG). Several orders of diffraction were clearly observable in MSHG, along with a strong dependence on the magnetization. Sizeable asymmetry between the MSHG signal measured in positive and negative diffraction peaks, especially visible in second order, are explained by Fresnel factors. It was found that first-order diffraction hysteresis loops differ from all others by showing an ''overshoot'' at magnetization reversal, both in MSHG and in the linear magneto-optical Kerr effect. Tentatively this behavior is explained as due to inhomogeneous reversal of the magnetization in the stripes

Measurement of tensor analyzing powers in deuteron photodisintegration

New accurate measurement of tensor analyzing powers T20, T21 and T22 in deuteron photodisintegration has been performed. Wide-aperture non-magnetic detectors allowed to cover broad kinematic ranges in a single setup: photon energy = 25 to 600 MeV, proton emission angle in CM = 24 to 48 deg. and 70 to 102 deg. New data provide a significant improvement of a few existing measurements. The angular dependency of the tensor asymmetries in deuteron photodisintegration is extracted for the first time.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let

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%

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