Thermobaric synthesis, structure, and properties of Dy x Cu 3V4O12

The perovskite-like compound Dy x Cu3V 4O12 (x = 0.67-0.75) is synthesized under high pressure (P = 4.0-9.0 GPa) and temperature (T = 1000 C). Its crystal structure is determined (Im-3 space group, Z = 2, a = 7.29348(7) Å) by means of powder X-ray diffraction. The basic lengths and bond angles are defined. It is found that the high-pressure phase of Dy x Cu3V 4O12 is characterized by metallic conductivity and paramagnetic properties. © 2013 Allerton Press, Inc

Synthesis and characterization of the new high pressure phases A Cu 3 v 4O 12 (A =Gd, Tb, Er)

New ACu3V4O12 (A=Gd, Tb, Er) phases have been prepared at high pressure and high-temperature conditions (P∼8-9 GPa, T∼1000°C) in a toroid-type high pressure cell. These compounds crystallize in the cubic symmetry with a perovskite-like structure. At ambient pressure, they are paramagnetic and have activation-type conductivity. The effect of high pressure (10-50 GPa) on the electrical properties of the materials was analyzed in the temperature range from 78 to 300 K. Pressure ranges of the transition from activation type to metallic conductivity have been determined. The crystal structure of ACu3V4O12 (A=Gd, Tb, Er) was found to be stable up to 50 GPa. © 2013 Copyright Taylor and Francis Group, LLC

Optimization of roll calibration for flange shape rolling. Groove space

The most important component of any rolling mill is the calibration of the rolls. The ability to obtain a finished product of high quality at minimal cost depends on the right calibration. According to the previous experience and practice a large number of different calibrations for the flange profiles production are known. The universal 'concept of two-stage optimization', consisting of two successively carried out optimization stages developed in the Department of Metal Forming of the Ural Federal University in relation to optimization of the roll calibration for flange shape rolling is considered in this article. Common features of these shapes classification and their variation levels are identified and justified. This developed classification structure is the basis for the formation of spaces of groove schemes, due to which the groove space is formed. In the software implementation the groove space is represented as a 'groove database'. In the future this database will be used to form the space of calibration schemes that are fundamentally suitable for these shapes rolling. © Published under licence by IOP Publishing Ltd.The reported study was funded by RFBR according to the research project 20-38-90246

Characteristics of autonomic status and school anxiety in schoolchildren with increased body mass index

BACKGROUND: In the Russian Federation, the incidence of obesity continues to grow among the child population. Vegetative imbalance and chronic stress play an important role in the pathogenesis of obesity and related health disorders. Timely identification of disorders of psycho-vegetative disorders and their correction in overweight children require an integrated approach of medical and pedagogical workers.AIM: To reveal the features of the vegetative status, the level of school anxiety in students with an increased body mass index.MATERIALS AND METHODS: Children with different body mass index (BMI) underwent a comparative analysis of the mean values and structure of revealed violations of cardiointervalography (heart rate variability, HRV) parameters, laboratory test parameters (plasma antioxidant activity, plasma malondialdehyde, triglycerides, total cholesterol, cortisol, magnesium and serotonin) and test parameters School Anxiety Scale of Phillips.RESULTS: The prevalence of overweight was 23.1%. The observation group consisted of 47 schoolchildren with a body mass index (BMI) +1–2 SD the comparison group consisted of 156 children with a normal BMI at the age of 10–15 years. The groups were comparable in terms of sex and age (p=0.629–0.771). Analysis of background HVR indices revealed a decrease in the values of parameters characterizing the activity of the parasympathetic division of the autonomic nervous system (ANS), with a simultaneous increase in the indicators of the sympathetic division of the ANS in the observation group relative to the comparison group (p=0.001–0.023); similar results were obtained during the orthostatic test. The cumulative assessment of CIG indicates a lower activity of the parasympathetic division in the regulation of the state of rest and a greater activity of the sympathetic division of the ANS in response to a stress factor in children with an increased BMI value. The children of the observation group showed higher levels of malondialdehyde (p = 0.041), triglycerides (p<0.001) and cortisol (p=0.093) with lower values of magnesium and serotonin (p=0.074–0.076). The analysis of the level of school anxiety showed that in children of the observation group the average level and frequency of the prevalence of high values of the indicator of general anxiety are higher in 1.3 and 2.5 (p=0.005), fear of self-expression — in 1.3 and 1.8 (p=0.080–0.086), fear of the situation of knowledge testing — by 1.5 (р=0.002) and 2.1 (p<0.001), the level of general anxiety — by 1.2 (р=0.090) and 2.3 times (p=0.036) relative to the comparison group. In the course of the mathematical analysis, the results were obtained indicating the relationship between the parameters of the vegetative and psychological status.CONCLUSION: The problem of excess nutrition remains an urgent issue of modern health care. Excess body weight is accompanied by the activation of the sympathoadrenal system with an increase in the level of school anxiety and all together forms a vicious circle. Excessive nutrition in school-age children requires an integrated approach of specialists in the medical and psychological-pedagogical sphere

Features of physical activity and school anxiety in pupils of the secondary general education school and the cadet corps

Relevance. The relevance of the study is due to the high significance of school anxiety in the formation of psychosomatic diseases and nervous disorders. Identification of risk factors for increased anxiety, one of which is low physical activity, is important for the timely organizing of preventive measures.The aim: to assess the characteristics of physical activity and school anxiety among schoolboys of secondary school and the cadet corps.Materials and methods. The observation group consisted of 47 schoolboys studying in a secondary general school at the age of 13–16; the comparison group consisted of 140 schoolboys of the cadet corps. The comparative assessment of physical activity bases on the analysis of the physical education implementation in educational organizations and the results of a survey according to the author’s questionnaire. A comparison was made of the parameters of bioimpedance analysis (BIA) of body composition, the content of cortisol and serotonin in the blood serum, and indicators of the Phillips school anxiety test.The results. Physical activity in the school system was limited to 3 hours per week, and in the additional education system there are only 14.9 % of schoolboys who devote 6–8 hours a week to sports, which is 3 times less than in the comparison group (46.4 %). Lower values of indicators of physical activity and body composition were found in secondary school boys relative to those in cadet corps (p = 0.015–0.038). The level of cortisol in the blood serum was 1.4 times higher, and the serotonin was 1.2 times less in schoolboys of the schools comparatively to cadets (p = 0.001–0.037). In secondary school schoolboys, relative to cadets, significantly 1.9–3.9 times more often increased values were recorded for the factor general anxiety at school, frustration of the need to achieve success, fear of self-expression, fear of the situation of testing knowledge, fear of not meeting the expectations of others, problems and fears in relations with teachers and general anxiety oppositely directed correlations of weak and moderate strength were established between the frequency and duration of physical education, BIA parameters, cortisol in the blood serum and factors of school anxiety.Conclusion. The values of the factors of school anxiety schoolboys of secondary general school are higher than in boys of the cadet corps and possibly they are associated with irregularity, relatively low duration of physical activity and the degree of development of metabolically active tissues

Influence of the aftereffect of mineral fertilizers on the productivity of a long-term phytocenosis in the conditions of the Privilyui agrolandscape of the middle taiga subzone of Yakutia

The article provides the research of 2011-2019 on studying the long-term influence of the aftereffect of 36-year application of mineral fertilizers on the productivity and nutritional value of long-term meadow phytocenoses. In a stationary experiment with a radical improvement of meadows, the following variants for applying mineral fertilizers were studied from 1974 to 2010: the minimum level was N62P60K11 (control), the average level was N202P175K43, and the maximum level was N318P362K189. In the conditions of the Privilyui agrolandscape of the middle taiga subzone of Yakutia, a long-term aftereffect of fertilizers (from 2011 to 2019) contributed to the preservation of the main dominant in the grass stand - couch grass (Elymus repens (L.) Nevski) up to 27.4-42.1 % and codominant – short-awned barley (Hordeum brevisubulatum (Trin) Link.) up to 14.7-24.3 %. During the aftereffect of fertilizers, the yield of cereal-forb phytocenosis averaged 1.71-2.03 t/ha of hay, which is 2.1-2.5 times higher than the yield of natural meadows. At the same time, hay forage contained up to 8.9-9.1 MJ of exchange energy, up to 0.62-0.65 feed units, and up to 80-90 g of digestible protein, which corresponds to the zootechnical norm

Pathological damage of thyroidopathy and the prevalence of thyroid diseases in children of the Perm region

Relevance. Thyroid diseases in children and adolescents rank first in the structure of endocrine pathology. An issue related to comparability of data on prevalence obtained with different procedures is vital given the necessity to intensify activities aimed at optimizing prevention of thyroid pathology.The aim. Comparative analysis of pathological lesions of thyropathies and the prevalence of thyroid gland diseases in children and adolescents living in the territory of the Perm region.Materials and methods. Prevalence of thyroid diseases was analyzed based on data taken from Statistic Form No. 12. Pathological damage caused by thyroid diseases was calculated based on results produced by medical examinations that included laboratory tests, ultrasound scanning of the thyroid gland, and a check-up by an endocrinologist. Calculation results were then compared with data taken from statistic reports. Influence exerted by sex and age on the growth in thyrotrophic hormone contents and thyroid gland volume was assessed by analyzing values in one-factor logistic regression models.Results. Prevalence of thyroid diseases, endemic goiter and subclinical hypothyroidism tends to decrease among children living in Perm region (р = 0.003–0.015) but prevalence of thyroiditis remains stable (р = 0.794). Having assessed prevalence among teenagers, we did not reveal any dynamics in prevalence of thyroid diseases and thyroiditis (р = 0.129–0.248); prevalence of endemic goiter went down in this age group (р = 0.008) whereas prevalence of subclinical hypothyroidism grew due to iodine deficiency (р = 0.012). The difference between pathological damage and prevalence of thyroid diseases reached 4.8–38.6 times. Having analyzed created logistic models, we were not able to identify sex or age as predictors of thyroid pathology occurrence.Conclusion. Prevalence of thyroid pathology was established to be by 4.8–38.6 times lower than pathological damage. Iodine deficiency on a given territory calls for developing regional medical and prevention programs aimed at diagnosing and preventing thyroid diseases caused by it