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Results of the analysis of interannual, seasonal, and diurnal variations in the ratios of the mixture of CH4, CO2, CO, benzene, and δ13C–CH4 in the surface air of Moscow based on the measurements at the station of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS), in 2018–2020 are presented. The annual maximum concentration of CH4, CO2, and CO (>2.2, 430, and 0.20 ppm, respectively) occurs in the winter months due to the seasonal increase in the anthropogenic load from the main sources of urban pollution: motor transport and thermal power plants and a decrease in the role of vertical air mixing. The greatest contribution of local and remote microbial sources to the CH4 concentration is noted in the summer months against the background of low δ13C–CH4 values (–50 to –60‰). In all seasons, CH4, CO2, and CO ground level peaks lasting up to several hours are due to the transport from industrial sites in the E–SE sector. The calculated mean emission ratios in urban air were CH4/benzene = 0.52–0.54 ppm/ppb, CH4/СО = 0.56–0.75 ppm/ppm, CO2/benzene = 77–93 ppm/ppb, CO2/СО = 81–131 ppm/ppm, and CO/benzene = 0.65–1.11 ppm/ppb. These ratios characterize the predominant contribution of emissions from motor transport and the heat and power equipment and can be used to refine the absolute values of emissions, including those on the basis of existing inventories of sources of anthropogenic air pollution. [ABSTRACT FROM AUTHOR]

We have studied the assessment of methane content in the near atmospheric layer of the Arctic seas and the sources of its emissions. Continuous atmospheric measurements of methane concentration and δ13C isotope signature in methane were carried out during two expeditions aboard the R/V Akademik Mstislav Keldysh in the summer and autumn of 2020. The minimum CH4 concentration (mean 1.937 ± 0.010 ppm) were obtained over the North and Norwegian Seas. The maximum CH4 concentration took place above the Kara (1.998 ± 0.030 ppm on average, maximum values are up to 2.000–2.040 ppm) and White (2.006 ± 0.030 ppm on average) seas. The average values of δ13C in the studied region were close to that typical for the Northern Hemisphere: –47.5‰. Regional changes in δ13C allowed CH4 sources to be identified and showed that the methane concentration in the surface atmospheric level is mainly affected by the direction of air-mass advection. [ABSTRACT FROM AUTHOR]

Background: The aim of the study was to assess the ratio of bone elements of the temporomandibular joint (TMJ) in children and adolescents with distal occlusion according to cone-beam computed tomography (CBCT)., Material and Methods: CBCT of the TMJ was analyzed in 121 patients aged 12-18 years, which were divided into two age groups: group I - children aged 12-15 years (62 cases in total, of which 47 patients with distal occlusion and 15 patients with physiological occlusion) and II group - adolescents aged 15-18 years (59 cases, of which 48 patients with distal occlusion and 11 patients with physiological occlusion). CBCT of the temporomandibular joint was performed by the standard method in the position of habitual occlusion and maximally open mouth. The size of the TMJ joint space in the anterior, upper and posterior sections was determined by the method of Rabukhina N.A., the analysis of the ratio of the bone elements of the TMJ was carried out using the Craniometry program., Results: The size of the joint space and the angle β of the temporomandibular joint in the anterior section on the right and left in children aged 12-15 with distal occlusion is increased compared to children with physiological occlusion in the position of habitual occlusion. In adolescents 15-18 years old with distal occlusion, the size of the TMJ joint space is increased in the anterior section on the right and left and reduced in the posterior section on the right, angle α is reduced on the right and left, angle β is reduced on the right, angle γ is increased on the right compared to adolescents with physiological occlusion. The revealed deviations indicate the presence of violations in the ratio of the bone elements of the TMJ, which are aggravated with age., Conclusion: Analysis of the results obtained during CBCT in children and adolescents allows us to correct the plan of orthodontic treatment and predict its results.

Analogues of the endogenous peptide corresponding to the 30-33 sequence of cholecystokinin (Trp-Met-Asp-Phe-NH2) were synthesized, and their biological activity was studied. It was shown that, in rats, the N-succinylated Nle2 analogue of this tetrapeptide exhibits increased anxiolytic properties in the dark-bright chamber test and an enhanced alcohol intake by both the control animals and the long-time alcohol-dependent animals under the conditions of free choice. Introduction of an isopropyl residue into the C-terminal amide of the Nle2 analogue resulted in the appearance of anxiolytic and antialcohol activity and the ability to increase the morphine analgesic effect in the tail-flick test on rats. The two synthesized analogues retained an affinity to cholecystokinin receptors.

The present study has been done in the framework of federal programme "Children of Chernobyl" with the aim to determine spread and structure of dental jaw abnormalities in children born and living in the radiation polluted regions after Chernobyl accident in 1986. 183 children have been examined in Donskoi town of Tula Province with the polluted soil by Cs-137 up to 5 Ci/km. All the examined children were divided into 2 groups: group 1--born in 1980-1986 and group 2--born in 1987-1994. It was determined that 76.5% of children have dental jaw system abnormalities. The most spread ones were occlusion abnormalities in combination with teeth abnormalities (28.9% cases) while the state of dental jaw system corresponding to the age standard was 2 times rarer in children born after the Chernobyl accident.

Sixty plaster models of the jaws of children aged 7 to 12 with normal occlusion have been examined and the correlations between the measured parameters analyzed. The authors recommend to use the relationship between the length of the anterior fragment of dentition and the sum of the mesiodistal sizes of 4 lower incisors for estimating the value of the former parameter.

The status of abutment tissues of permanent teeth was studied in patients with dense position of teeth, aged 13 to 18. Time course of periodontal changes at different stages of orthodontic treatment with permanent devices was followed up.

The height of permanent teeth crowns was measured and the status of supporting tissue studied with the use of a Periotest apparatus (Siemens, Germany) in 95 children aged 7-12 with physiologic dental occlusion and in 70 age-matched children without dental occlusion in the frontal section. The data obtained by this apparatus permit a judgement on exercise tolerance of periodontal tissue. The size of the vertical fissure between maxillary and mandibular anterior teeth was measured in the children with abnormal occlusion and analysis of correlations and regressions of this parameter with the height of permanent teeth crown was carried out. The findings evidence that dental supporting tissue strength changes with age, as the maxillodental system develops, and that this characteristic is rather low in the children with non-occluding frontal teeth.

Chronic morphine treatment has been shown to cause the development of hyperreactivity of the dopamine system detected as the increased behavioral and biochemical responses to the action of specific dopamine agonists. Furthermore, inverted changes in animal behavioral reactivity to the stimulation of presynaptic, proposed D-2 receptors by apomorphine in a low dose was found in our previous study when morphine was chronically used in animals under conditions of restraint. To estimate the nature and proposed receptor mechanisms of changes found in behavioral reactivity due to chronic morphine administration in aversive life conditions at the level of highly sensitive D-2 receptors, the density and affinity of [3H] spiroperidol binding sites was studied in these animals two weeks after the last opiate administration. Increased density and affinity of D-2 receptors probably indicating their hypersensitivity was found in animals chronically exposed to two-hour restraint stress, while a significant decrease in density accompanied by increase in affinity of these receptors was typical to rats chronically exposed to morphine under conditions of restraint. The data are discussed in aspects of quantitative and qualitative changes in D-2 receptors, and their proposed mechanisms and functional significance in the mediation of modified organism's functional state due to chronic opiate administration in different environmental conditions.

In 70 children with deep prognathic occlusion while in the period of second dentition the correlations were investigated between the angular parameters of teleroentgenograms in a triangular manner: each parameter was related to the two others, and those were compared to each other.