Infrared thermography study of the fatigue crack propagation

The work is devoted to the experimental study of heat dissipation process caused by fatigue crack propagation. To investigate a spatial and time temperature evolution at the crack tip set of experiments was carried out using specimens with pre-grown centered fatigue crack. An original mathematical algorithm for experimental data treatment was developed to obtain a power of heat source caused by plastic deformation at crack tip. The algorithm includes spatial-time filtration and relative motion compensation procedures. Based on the results of mathematical data treatment, we proposed a way to estimate the values of J-integral and stress intensity factor for cracks with pronounced the plastic zone

Microlensing effects and structure of gravitational lens systems

A study of gravitational microlensing of distant objects is presented. We performed simulations of light curves and trajectories of the image centroid of an extended source in the Chang–Refsdal lens with shear and continual dark matter. Various brightness distributions over the source (Gaussian, power-law, Shakura–Synyaev accretion disc) have been studied. We considered in detail approximate relations and corresponding algorithms used to fit observational data on high amplification events (HAE). The results are applied to interpretation of HAE observed by OGLE and GLITP groups. The source size and caustic crossing moment are estimated from these data, however, the determination of the brightness profile is statistically not reliable

Infrared thermography study of the fatigue crack propagation

The work is devoted to the experimental study of heat dissipation process caused by fatigue crack propagation. To investigate a spatial and time temperature evolution at the crack tip set of experiments was carried out using specimens with pre-grown centered fatigue crack. An original mathematical algorithm for experimental data treatment was developed to obtain a power of heat source caused by plastic deformation at crack tip. The algorithm includes spatial-time filtration and relative motion compensation procedures. Based on the results of mathematical data treatment, we proposed a way to estimate the values of J-integral and stress intensity factor for cracks with pronounced the plastic zone

СОДЕРЖАНИЕ ЛИПИДОВ, АДИПОКИНОВ И ГРЕЛИНА ПРИ РАЗВИТИИ ИНСУЛИНОРЕЗИСТЕНТНОСТИ У ПАЦИЕНТОВ С ИНФАРКТОМ МИОКАРДА

Aim. The estimate insulin resistance in myocardial infarction. Patients and methods. The study involved 200 patients with myocardial infarction, in which on the 1st and 12th day of hospitalization measured glucose, insulin, insulin resistance index (IR), lipid profile, the concentration of adipokines and ghrelin. Results. IR was detected in 77% of patients and was associated with a history of factors of cardiovascular risk, adverse clinical course of the disease, lipid disorders. The most important marker was the level of free fatty acids. High risk associated with increased in 9 times the concentration of free fatty acids in blood plasma. Patients with IR observed increased concentrations of leptin, resistin, and reduced the protective effect of adiponectin. The high specificity and sensitivity characteristic of the concentration of ghrelin: its reduction by 4 times in the acute phase of myocardial infarction increases the risk of MI by 78%. Conclusions. Significant risk factors for MI myocardial infarction, along with insulinemia and glycemia, is to increase the concentration of free fatty acids and the disbalance in the system adipokines against deficiency of ghrelin in acute and early recovery periods of the disease. Free fatty acids and ghrelin are promising markers to stratify the risk of insulin resistance in patients with myocardial infarction. Цель исследования: оценка инсулинорезистентности при инфаркте миокарда. Пациенты и методы:  в исследование включено 200 пациентов с инфарктом миокарда,  у которых на 1-е и 12-е сут госпитализации определяли содержание глюкозы, инсулина, индекс инсулинорезистентности (ИР), показатели липидного профиля, концентрацию адипокинов и грелина. Результаты: ИР была выявлена у 77% больных и ассоциировалась с наличием в анамнезе факторов сердечно-сосудистого риска, неблагоприятным клиническим течением заболевания, нарушением липидного обмена. Наиболее информативным маркером оказался уровень свободных жирных кислот. Высокий риск развития ИР связан с возрастанием  в 9 раз концентрации свободных жирных кислот в плазме крови. У больных с ИР наблюдается увеличение концентрации лептина, резистина, и снижение защитного действия адипонектина. Высокая специфичность и чувствительность характерна для концентрации грелина: ее снижение в 4 раза в остром периоде инфаркта миокарда повышает риск развития ИР на 78%.Выводы: значимыми факторами риска ИР при инфаркте миокарда, наряду с инсулинемией и гликемией, является увеличение  концентрации  свободных жирных кислот и дисбаланс в системе адипокинов  на фоне дефицита грелина в остром и раннем восстановительном периодах заболевания. Свободные жирные кислоты и грелин являются перспективными маркерами для стратификации риска развития инсулинорезистентности у больных с инфарктом  миокарда.

РАСПРОСТРАНЕННОСТЬ ПИЩЕВОЙ АЛЛЕРГИИ У ДЕТЕЙ В МИРОВОМ ОЧАГЕ ОПИСТОРХОЗА: ПЛАНИРОВАНИЕ И МЕТОДОЛОГИЯ ЭПИДЕМИОЛОГИЧЕСКОГО ИССЛЕДОВАНИЯ EUROPREVALL

According to numerous surveys food allergy affects up to 2–6% of population in different countries and varies due to numerous factors including the prevalence of helminths infestation. The food allergy prevalence data in Russia are based on official medical statistics. The study was performed as part of «The Prevalence, Cost and Basis of Food Allergy Across Europe» (EU funded project № FP6-2006-TTC-TU-5 Proposal 045879 EuroPrevall). The aim is to create the concept of food allergy in children in opisthorchiasis endemic area based on epidemiological study of the prevalence, risk factors and clinical features. The main objective of the study will be the working out of the food safety regulations. This article describes the study design and its methodology. Согласно данным ряда исследователей, распространенность пищевой аллергии в мире составляет 2–6%, варьируя в зависимости от многочисленных факторов, включая пораженность населения гельминтными инвазиями. Сведения о распространенности пищевой аллергии в России основаны на данных официальной статистики. Настоящая работа выполнена в рамках «Исследования распространенности, социально-экономического значения и основ пищевой аллергии в Европе» («The Prevalence, Cost and Basis of Food Allergy Across Europe»; грант VI рамочной программы Евросоюза № FP6-2006-TTC-TU-5 Proposal 045879 EuroPrevall). Цель исследования состоит в формулировке новой концепции пищевой аллергии у детей в мировом очаге описторхоза на основании эпидемиологического исследования распространенности, факторов риска, клинических особенностей болезни, а также в создании научной базы для разработки регламентов безопасности продуктов питания. Статья посвящена вопросам планирования и методологии исследования.

Occupational reporiductive system diseases in female workers employed at worplaces with harmful working conditions

The paper outlines the data obtained in the course of long-term research dedicated to studying the extent to which re-productive system pathologies in workers with high-risk occupations are occupationally induced. Their peculiarity is joint impacts of various occupational factors (for example, impacts exerted by chemicals together with physical and biological factors, and labor hardness and intensity as well) on a female body. Our research goal was to examine the extent to which reproductive system pathologies in workers with high-risk occupations were occupationally induced. To achieve it, we applied statistical estimate of correlation between health disorders and work. Our occupational group included a number of occupations with harmful or hazardous working conditions in civil en-gineering, metallurgy, chemical industry, polymer-processing industry, and health care as well. As a rule, working condi-tions class of workers from the examined groups varied from 3.1 to 3.3; and occupation with permissible working conditions were used as a comparative group. The research results revealed that there are certain occupations with high risk of reproductive health disorders evolvement and infants development pathologies evolvement. They are: – model makers and checkers in civil engineering and crane operators at a metallurgic plant; – analysts at chemical analysis laboratories, chemical engineers in chemical industry (including petrochemical plants, polymer-processing plants, and organic synthesis plants); – surgeons, obstetrician-gynecologists, midwives, surgical nurses working in in-patient departments. Estimate of correlation and occupational dependence of reproductive system diseases on working conditions revealed that women with harmful working conditions (3.1–3.3 hazard class) had defective pregnancies or labor pathologies which had strong and average correlation with working conditions. Health disorders in newborns were estimated as per very strong corre-lation with mother's work. Thus, we can state that a mother occupational risk induction for a child health is fundamentally proved. On the basis of the obtained results we rank female workers with 3 class 2 harm degree working conditions as having an occupation with high risks of reproductive health disorders. We worked out an algorithm aimed at managing these risks; it should be applied in order to lower occupational risks for reproduction in female workers

Liver pathology in hypo- and hyperthyroidism (literature review)

The thyroid gland is an endocrine organ, the product of which are iodinecontaining hormones - triiodothyronine and thyroxine. Violation of the concentration of iodothyronines in the blood plasma can lead to the occurrence of pathological processes in other organs, in particular, the liver. The hypothyroid state leads to a decrease in the synthetic function of the liver, worsens the course of the metabolic syndrome, leading to the development of non-alcoholic fatty liver disease, morphologically manifested as steatohepatitis with minimal changes. In hyperthyroidism, in addition to autoimmune and druginduced hepatitis, there are cholestatic and hepatitis forms of liver damage. Cholestatic lesion consists in the development of centrilobular intrahepatocyte cholestasis, clinically and laboratory manifested by the development of cholestatic syndrome. Hepatitis liver damage is manifested by the development of clinical, laboratory and morphological signs of acute hepatitis. The review provides up-to-date information on biochemistry, theories of development, pathogenesis and pathomorphology of liver pathologies that occur in thyroid gland pathologies accompanied by hypo- and hyperthyroidism. Data from both clinical and experimental studies are presented

Innovation and development prospects of pre-university education of Saratov State Medical University

The article considers innovative methods used in the pre-university education at Saratov State Medical University and directed to the modernization of educational program. It points out that competence-based approach includes the following components — problem teaching and adaptive system, heuristic teaching, personal approach to teaching, computerization, distant education technologies and integration-module technolog