Optical echo in photonic crystals

The dynamics of photonic wavepacket in the effective oscillator potential is studied. The oscillator potential is constructed on a base of one dimensional photonic crystal with a period of unit cell adiabatically varied in space. The structure has a locally equidistant discrete spectrum. This leads to an echo effect, i.e. the periodical reconstruction of the packet shape. The effect can be observed in a nonlinear response of the system. Numerical estimations for porous-silicon based structures are presented for femtosecond Ti:Sapphire laser pump.Comment: 4 page

Borrmann Effect in Photonic Crystals: Nonlinear Optical Consequences

Nonlinear-optical manifestations of the Borrmann effect that are consequences of the spectral dependence of the spatial distributions of the electromagnetic field in a structure are observed in one-dimensional photonic crystals. The spectrum of the light self-focusing effect corresponding to the propagation-matrix calculations has been measured near the edge of the photonic gap.Comment: 4 pages, 3 figures, published in russian at Pis'ma v Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki, 2008, Vol. 87, No. 8, pp. 461-46

Study of Thermodynamic Quantities in Generalized Gravity Theories

In this work, we have studied the thermodynamic quantities like temperature of the universe, heat capacity and squared speed of sound in generalized gravity theories like Brans-Dicke, Ho$\check{\text r}$ava-Lifshitz and $f(R)$ gravities. We have considered the universe filled with dark matter and dark energy. Also we have considered the equation of state parameters for open, closed and flat models. We have observed that in all cases the equation of state behaves like quintessence. The temperature and heat capacity of the universe are found to decrease with the expansion of the universe in all cases. In Brans-Dicke and $f(R)$ gravity theories the squared speed of sound is found to exhibit increasing behavior for open, closed and flat models and in Ho$\check{\text r}$ava-Lifshitz gravity theory it is found to exhibit decreasing behavior for open and closed models with the evolution of the universe. However, for flat universe, the squared speed of sound remains constant in Ho$\check{\text r}$ava-Lifshitz gravity.Comment: 15 pages, 12 figure

Amateur sport and emotional burnout formation in high school students

Practicing sports, as well as physical activity in general, contribute to a healthy lifestyle, help to prevent numerous chronic diseases, and play a therapeutic role in addressing a number of cognitive and psychological disorders (such as depression, distorted body image and self-perception and low self-esteem). As regards students, freshmen with higher physical capabilities can better adapt to new college environment, which in turn influences their well-being, psychological state and ability to study. The aim of our study was to detect the level of emotional burnout and individual psychological characteristics of the university students, engaged in amateur sports. It was shown that the group of amateur sportsmen demonstrated higher level of arousal and mobility of neural processes, and lower level of neuroticism, lower level of neurotisation, anxiety, psychic tension and depression. This allows us to conclude that the type of nervous system may define the disposition toward the physical activity, and the strength of nervous system determines the ability to achieve success in sports. Our data indicate that practicing sports prevent the development of burnout, reduce the negative impact of daily emotional stress and provide a socially acceptable way to express aggression

The production of hyperimmune pseudotuberculosis sera

Background. Pseudotuberculosis remains a serious public health problem, which dictates the need to develop simple and rapid diagnostic methods for this disease. The effectiveness of the latter largely depends on the activity and specificity of the diagnostic sera. Currently, in our country, a diagnostic serum for Yersinia pseudotuberculosis O-monovalent (serotype I, III) is produced with a regulated area of application: for an approximate agglutination reaction on glass (Pasteur NIIEM, St. Petersburg). Preparation of pseudotuberculosis sera for a wider scope of their use, in particular, as a  source of specific antibodies in the design of diagnostic immunobiological preparations and test systems for pseudotuberculosis, is relevant and in demand in healthcare practice.Aims. To obtain hyperimmune pseudotuberculosis sera, promising for use in the practice of laboratory studies for pseudotuberculosis.Materials and methods. Chinchilla rabbits aged 3–6 months, weighing 2.5–3.0 kg served as animal producers of pseudotuberculosis sera. As immunogens, we used a corpuscular antigen (CAg) - a suspension of cells of the epidemically significant Yersinia pseudotuberculosis 3704 O: 1b strain isolated by an outbreak of pseudotuberculosis in the town of Zima, Irkutsk region, inactivated by boiling, and a preparation obtained from the outer membranes, containing the main surface immunogen of the strain. For the adsorption of experimental sera, in order to minimize the nonspecific response, we used heterologous microorganisms Escherichiacoli, Salmonella typhimurium, Shigella flexneri and Y. enterocolitica O:3, which have a similarity of surface antigenic structures with the causative agent of  pseudotuberculosis. The presence of specific antibodies in experimental pseudotuberculosis sera was determined in a volumetric agglutinationreaction.Results. Optimal schemes of rabbit immunization were selected, which made it possible to obtain hyperimmune sera against Y. pseudotuberculosis 3704 O:1b antigens with an agglutination activity of 1:3200-1:6400. In low dilutions of experimental sera (1:100–1:400), obtained against corpuscular antigen and outer membrane antigens (Escherichia coli, Salmonella typhimurium, Shigella flexneri , Y. enterocolitica О:3, S . enteritidis Gartnery) was observed in the agglutination reaction (AR). After the adsorption of experimental pseudotuberculosis sera by cells of heterologous strains, there was no cross-reaction with the indicated microorganisms in the  agglutination reaction.Conclusions. The obtained hyperimmune adsorbed sera against the boiling-inactivated Y. pseudotuberculosi s 3704 O: 1b corpuscular antigen and outer membrane antigens can be used as a source of specific antibodies in the design of diagnostic immunobiological preparations for the detection of pseudotuberculosis microbe, as well as in the monitoring of the epidemic situation

Using dot-immunoassay in decoding the outbreak of pseudotuberculosis in the Tomsk region

Background. Pseudotuberculosis remains a serious healthcare problem, which determines the expediency of developing the express methods for its early diagnosis. To detect the pathogen, we designed test system for dot-immunoassay (DIA) based on antibodies labeled with silver nanoparticles (SNPs) isolated from hyperimmune rabbit serum obtained against killed cells of  Yersinia pseudotuberculosis of O:1b serovariant.The aim. To assess the possibility of using dot-immunoassay for express identification of Y. pseudotuberculosis cultures isolated from clinical material and environmental objects at the initial stage of bacteriological study during laboratory diagnosis of the disease.Methods. We used the materials from the outbreak of pseudotuberculosis in the Krylovskaya Boarding School of the Bakcharsky district of the Tomsk region in 2021. Specific antibodies from hyperimmune rabbit sera obtained against Y. pseudotuberculosis 3704 particulate antigen of O:1b serotype were labeled with SNPs and used in DIA on nitrocellulose membranes with visualization of reaction results with a solution of a physical developer. The presence of the causative agent of pseudotuberculosis in the test material was inferred by the formation of gray spots of different intensity (from 4+ to 1+).Results. All Y.  pseudotuberculosis strains isolated using bacteriological method on  the second day of the study from clinical material obtained from sick people and environmental objects were detected in DIA at concentrations ≥ 3.1 × 104 microbial cells per milliliter (m.c./ml).Conclusion. The designed test system for dot-immunoassay using SNPs as a marker of specific antibodies for the detection of Y.  pseudotuberculosis in cultures isolated from swabs from vegetables and clinical material from patients, including those  with  mixed infection, allows us to  detect a specific corpuscular antigen with a high sensitivity (≥ 3.1 × 104 m.c./ml), providing express identification of isolated cultures at the initial stage of bacteriological study

Characteristic of the active substance of the Saccharomyces cerevisiae preparation having radioprotective properties

The paper describes some biological features of the radioprotective effect of double-stranded RNA preparation. It was found that yeast RNA preparation has a prolonged radioprotective effect after irradiation by a lethal dose of 9.4 Gy. 100 % of animals survive on the 70th day of observation when irradiated 1 hour or 4 days after 7 mg RNA preparation injection, 60 % animals survive when irradiated on day 8 or 12. Time parameters of repair of double-stranded breaks induced by gamma rays were estimated. It was found that the injection of the RNA preparation at the time of maximum number of double-stranded breaks, 1 hour after irradiation, reduces the efficacy of radioprotective action compared with the injection 1 hour before irradiation and 4 hours after irradiation. A comparison of the radioprotective effect of the standard radioprotector B-190 and the RNA preparation was made in one experiment. It has been established that the total RNA preparation is more efficacious than B-190. Survival on the 40th day after irradiation was 78 % for the group of mice treated with the RNA preparation and 67 % for those treated with B-190. In the course of analytical studies of the total yeast RNA preparation, it was found that the preparation is a mixture of single-stranded and double-stranded RNA. It was shown that only double-stranded RNA has radioprotective properties. Injection of 160 μg double-stranded RNA protects 100 % of the experimental animals from an absolutely lethal dose of gamma radiation, 9.4 Gy. It was established that the radioprotective effect of double-stranded RNA does not depend on sequence, but depends on its double-stranded form and the presence of “open” ends of the molecule. It is supposed that the radioprotective effect of double-stranded RNA is associated with the participation of RNA molecules in the correct repair of radiation-damaged chromatin in blood stem cells. The hematopoietic pluripotent cells that have survived migrate to the periphery, reach the spleen and actively proliferate. The newly formed cell population restores the hematopoietic and immune systems, which determines the survival of lethally irradiated animals

Development of the therapeutic regimen based on the synergistic activity of cyclophosphamide and double-stranded DNA preparation which results in complete cure of mice engrafted with Krebs-2 ascites

Cumulative evidence obtained in this series of studies has guided the logic behind the development of a novel composite dsDNA-based preparation whose therapeutic application according to the specific regimen completely cures the mice engrafted with otherwise lethal Krebs-2 ascites. The likely mechanism involves elimination of TAMRA+ tumor-inducing stem cells (TISCs) from Krebs-2 tumors. We performed quantitative analysis of TISC dynamics in Krebs-2  ascites following treatment with the cytostatic drug cyclophosphamide (CP) and untreated control cells. In intact ascites, TISC percentage oscillates around a certain value. Following CP treatment and massive apoptosis of committed cancer cell subpopulation, we observed relative increase in TISC percentage, which is consistent with reduced susceptibility of TISCs to CP. Nonetheless, this treatment apparently synchronizes TISCs in a cell cycle phase when they become sensitive to further drug treatments. We describe the regimen of synergistic DNA + CP activity against Krebs-2 ascites. This protocol results in a complete cure of 50 % of Krebs-2 engrafted mice and involves three metronomic injections of CP exactly at the timepoints when repair cycles are about to finish combined with dsDNA injections 18 hours following each CP injection. The “final shot” uses CP + DNA treatment, which targets the surviving yet highly synchronized and therefore treatmentsensitive cells. The first three CP/DNA injections appear to arrest Krebs-2 cells in late S-G2-M phase and result in their simultaneous progression into G1-S phase. The timing of the “final shot” is crucial for the successful treatment, which eradicates tumorigenic cell subpopulation from Krebs-2 ascites. Additionally, we quantified the changes in several biochemical, cellular and morphopathological parameters in mice throughout different treatment stages

The role of molecular methods in diagnosis of opportunistic diseases in HIV-infected patients

Objective: to assess the diagnostic significance ot opportunistic diseases pathogens detection in biological samples from HIV- infected patients. Methods: in 2007-2013,4133 adult hospital patients were examined (76% had AIDS; CD4 blood count < 200 cells/mcL - 75%). 6847 biological samples (blood samples, BAL, CSF, etc.) were examined for M. tuberculosis, Cytomegalovirus, C. albicans, C. glabrata, C. cruzei, C. neoformins, T. gondii, H. Simplex l-ll, HerpesVI, Epstein-Barr virus (EBV) and JC-virus DNAs, and HIV RNA presence and concentration (PCR-test in Federal Budget Institution of Science 'Central Research Institute of Epldemiol-ogy* was used). Results: The role of the main opportunistic diseases pathogens DNA presence and concentrations in biological fluids and tissues in diagnosis was established; the central role of molecular methods in prompt diagnosis of opportunistic diseases in HIV-infected people was proven.С целью определения диагностического значения выявления ДНК возбудителей вторичных заболеваний в биологических материалах у больных ВИЧ-инфекцией в 2007-2013 гг. обследовано 4133 стационарных взрослых пациентов (в стадии 4Б (СПИД) - 4В (СПИД) - 76%, количеством С04-лимфоцитов в крови <200 кл/мкл - 75%). Исследовано 6847 биоматериалов (образцов крови, БАЛЖ, СМЖ и др.) на наличие и количественное определение ДНК М. Tuberculosis, Cytomegal-ovirus, С. albicans, С. glabrata, С. cruzei, С. neoformins, Т. gondii, Н. Simplexl-ll, HerpesVI, ВЭБ, JC-вируса, РНК ВИЧ молекулярными методами (ПЦР-тест-системы ФБУН «Центральный НИИ эпидемиологии» Роспотребнадзора). Установлено диагностическое значение качественного и количественного содержания ДНК возбудителей основных оппортунистических заболеваний в биологических жидкостях и тканях; обоснована центральная роль молекулярных методов в своевременной постановке этиологического диагноза вторичных патологий у больных ВИЧ-инфекцией