Analysis of hemodynamic changes in vertebral arteries and veins during functional tests with ultrasound monitoring

Aim to evaluate the correlation between the course of vertebral arteries and veins and the results of calculations of hemodynamic parameters during ultrasound with functional tests. Material and methods. In the observation, 252 volunteers were examined using Samsung SonoAce R7 and GE Logiq F6 equipment. The hemodynamics was studied at the level of the second segment of the vertebral arteries and veins at rest, when turning, tilting and lifting the head. The results were processed using Microsoft Excel 2007 with subsequent statistical analysis. Results. 504 vascular complexes were analyzed without taking into account the visualization side. When assessing the arteries, the highest maximum blood flow velocity was registered when lifting the head in women with a rectilinear course of the vessels. In the group of men with non-rectilinear course of vessels, the lowest average blood flow velocity was registered when tilting the head. The highest volume flow was recorded in case of non-rectilinear vascular course in women when lifting the head. For vertebral veins, the highest indicators of maximum and minimum venous blood flow rates were observed in men with a rectilinear course of vessels when lifting the head. The highest values of the average flow velocity and volume flow were noted in men who had a rectilinear course of the vessels. The maximum values of the calculated venous volume flow were registered in groups with rectilinear vascular course: in men up to 19.4214.85 ml/min. (Me 12.45 ml/min.), in women 18.52 15.30 ml/min. (Me 10.50 ml/min.). Conclusion. The data obtained by the study contributes to improving the software and analysis of individual changes during patient examination, helps to evaluate the effectiveness of treatment and rehabilitation, as well as to analyze multifactorial models

Regular patterns in the size ratio of the cervical vertebral bodies registered by MRI in the axial plane

Aim – to find regular patterns in the morphometric characteristics for the bodies of the cervical vertebrae when performing measurements in the axial (transverse) plane in men and women with different severity of degenerative-dystrophic changes of the cervical spine. Material and methods. The material of the study was the tomograms of 75 men and 128 women aged 18 to 84 years, obtained on magnetic resonance tomographs with a magnetic field strength of 1 Tl and 1.5 Tl. The data was divided into several groups according to the patients' sex and severity of degenerative-dystrophic changes of the cervical spine. The length and width of the vertebral bodies in the axial plane were measured with the subsequent calculation of their ratio. Results. Significant differences were found between the 1st and 2nd groups for the width of C7-C4 in women, as well as for the length of C3 and width of C3, C2 in men. Significant difference in the ratio of the sizes of vertebral bodies was registered in the 1st and 2nd groups of women at the level of C7. When comparing the data of all observation groups among men, significant differences were noted in the 2nd and 3rd groups for C7, C6, C3. With progression of degenerative-dystrophic changes, the differences in length were significant for C7-C4, C2 vertebrae in the 1st group, for C7-C5, C2 – in the 2nd and C7, C6, C4-C2 in the 3rd group. In the group of men with pronounced changes in the cervical spine region, in most cases there was an increase in coefficients (with significant differences in data for the 2nd and 3rd groups). Conclusion. Among men, significant differences were observed between the 2nd and 3rd groups for C7, C6, C3. For the C2 vertebra, significant differences were noted, taking into account sex, for length in the 1st and 3rd groups, width – in the 1st and 2nd groups, when assessing the mutual ratio of the sizes of the vertebral bodies – in the 2nd and 3rd groups

Prevalence and genetic diversity of the <i>Alongshan virus (Flaviviridae)</i> circulating in ticks in the south of Eastern Siberia

Introduction. Tick-borne infections are of great importance for many regions of Russia, including Eastern Siberia. This unfavorable epidemiological situation can be characterized not only by the circulation of well-known tick-borne infections, but also by the identification of new pathogens, the role of which remains little or generally unexplored. Multicomponent flavi-like viruses can cause infectious diseases in humans and pose a threat to public health. The purpose of the study was the identification and molecular genetic characterization of the Alongshan virus (Flaviviridae, ALSV) isolates, transmitted by ticks in the south of Eastern Siberia. Materials and methods. Total 1060 ticks were collected and analyzed from the territory of the Republics of Khakassia, Tuva, Buryatia, Irkutsk Region and Transbaikal Territory (Zabaykalsky Krai) in the spring-summer period 2023. ALSV RNA was detected by RT-PCR followed by nucleotide sequence determination and phylogenetic analysis for each segment of the genome. Results. The ALSV infection rate in Ixodes persulcatus ticks collected in the Republic of Khakassia was 3.3% (95% CI: 1.4–7.5); in Irkutsk Oblast – 1.0% (95% CI: 0.3–3.7); in the Republic of Tuva – 0.9% (95% CI: 0.3–3.4) and in Transbaikal Krai – 0.7% (95% CI: 0.2–3.6). Sequences of all four segments of ALSV genetic variants circulating in I. persulcatus ticks in the south of Eastern Siberia are grouped with sequences found in China and clustered into the Asian subgroup transmitted by taiga ticks. The level of difference in the nucleotide sequences of genome fragments among the identified genetic variants of ALSV ranged from 2 to 3%. Conclusion. The article shows the widespread distribution of ALSV in I. persulcatus ticks in the Republics of Khakassia and Tyva, Irkutsk Oblast and Transbaikal Territory. The obtained data actualize monitoring of changes in the area of distribution of potentially dangerous for humans flavi-like viruses and their vectors

No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations

The detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere, which-given methane's lifetime of several centuries-predicts an even, well mixed distribution of methane. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally

Martian dust storm impact on atmospheric H₂O and D/H observed by ExoMars Trace Gas Orbiter

Global dust storms on Mars are rare but can affect the Martian atmosphere for several months. They can cause changes in atmospheric dynamics and inflation of the atmosphere, primarily owing to solar heating of the dust. In turn, changes in atmospheric dynamics can affect the distribution of atmospheric water vapour, with potential implications for the atmospheric photochemistry and climate on Mars. Recent observations of the water vapour abundance in the Martian atmosphere during dust storm conditions revealed a high-altitude increase in atmospheric water vapour that was more pronounced at high northern latitudes, as well as a decrease in the water column at low latitudes. Here we present concurrent, high-resolution measurements of dust, water and semiheavy water (HDO) at the onset of a global dust storm, obtained by the NOMAD and ACS instruments onboard the ExoMars Trace Gas Orbiter. We report the vertical distribution of the HDO/H O ratio (D/H) from the planetary boundary layer up to an altitude of 80 kilometres. Our findings suggest that before the onset of the dust storm, HDO abundances were reduced to levels below detectability at altitudes above 40 kilometres. This decrease in HDO coincided with the presence of water-ice clouds. During the storm, an increase in the abundance of H2O and HDO was observed at altitudes between 40 and 80 kilometres. We propose that these increased abundances may be the result of warmer temperatures during the dust storm causing stronger atmospheric circulation and preventing ice cloud formation, which may confine water vapour to lower altitudes through gravitational fall and subsequent sublimation of ice crystals. The observed changes in H2O and HDO abundance occurred within a few days during the development of the dust storm, suggesting a fast impact of dust storms on the Martian atmosphere