Lipidomic profile of seminal plasma in non-obstructive azoospermia with sperm maturation arrest

Introduction. The difference between obstructive and non-obstructive azoospermia with sperm maturation arrest is important for the choice of treatment tactics and adequate counseling of a married couple.Purpose of the study. The study aimed to assess the semen lipid profile in patients with sperm maturation arrest. Materials and methods. Samples of seminal plasma for lipid composition of 24 men with normozoospermia and 64 men with azoospermia were studied. Patients with azoospermia underwent microdissection testicular biopsy followed by the detection of testicular tissue pathology. Lipid extracts were analyzed by liquid chromatography with mass spectrometry. Lipid data were compared with the results of pathomorphological studies.Results. Comparison of two groups revealed a statistically significant concentration differences for 22 lipids detected in positive-ion mode and 11 lipids detected in negative-ion mode. Those lipids mainly belong to the classes hexosylceramides, sphingomyelins and phosphatidylcholines — simple ethers and oxidized lipids. In multivariate analysis, the following lipids were found to be statistically significant predictors of sperm maturation arrest: PC 16: 0_22: 6 lipid (β-coefficient: -0.73; 95% confidence interval (95% CI): -1.42 to -0.27; odds ratio (OR): 0.48; OR CI: 0.24 to 0.76; Wald's test: -2.58; p = 0.01), SM d20: 1/22:2 lipid (β-coefficient 4.96; 95% CI 2.29 to 9.13; OR: 142.31; OR CI: 9.90 to 9.22^103; Wald's test: 2.93; p = 0.003); PG 20:3_22: 6 lipid (β-coefficient 2.52; 95% CI 1.13 to 4.49; OR: 12.37; OR CI: 3.10 to 89.27; Wald's test: 3.02; p = 0.002); PC O- 16: 1/16:0 lipid (β-coefficient 1.96; 95% CI -4.12 to 0.27; OR: 0.14; OR CI: 0.02 to 0.76; Wald's test: -2.05; p = 0.04). The prediction model characteristics of sperm maturation arrest, obtained during cross-validation in the positiveion mode composed: sensitivity 91%, specificity 85%; in negative-ion mode: sensitivity 75%; specificity 81%.Conclusions. Even though early stages of spermatogenesis are equally preserved in both fertile men and men with homogeneous sperm maturation arrest, the semen in the studied group of patients differed in its lipid profile. Patients with non-obstructive azoospermia, associated with meiosis arrest, may have unique lipidomic characteristics of seminal plasma, which in the future will make it possible to differentiate various variants of severe male infertility using non-invasive methods

The dynamics of vortex generation in superfluid 3He-B

A profound change occurs in the stability of quantized vortices in externally applied flow of superfluid 3He-B at temperatures ~ 0.6 Tc, owing to the rapidly decreasing damping in vortex motion with decreasing temperature. At low damping an evolving vortex may become unstable and generate a new independent vortex loop. This single-vortex instability is the generic precursor to turbulence. We investigate the instability with non-invasive NMR measurements on a rotating cylindrical sample in the intermediate temperature regime (0.3 - 0.6) Tc. From comparisons with numerical calculations we interpret that the instability occurs at the container wall, when the vortex end moves along the wall in applied flow.Comment: revised & extended version. Journal of Low Temperature Physics, accepted (2008

Thermal counterflow in a periodic channel with solid boundaries

We perform numerical simulations of finite temperature quantum turbulence produced through thermal counterflow in superfluid 4He, using the vortex filament model. We investigate the effects of solid boundaries along one of the Cartesian directions, assuming a laminar normal fluid with a Poiseuille velocity profile, whilst varying the temperature and the normal fluid velocity. We analyze the distribution of the quantized vortices, reconnection rates, and quantized vorticity production as a function of the wall-normal direction. We find that the quantized vortex lines tend to concentrate close to the solid boundaries with their position depending only on temperature and not on the counterflow velocity. We offer an explanation of this phenomenon by considering the balance of two competing effects, namely the rate of turbulent diffusion of an isotropic tangle near the boundaries and the rate of quantized vorticity production at the center. Moreover, this yields the observed scaling of the position of the peak vortex line density with the mutual friction parameter. Finally, we provide evidence that upon the transition from laminar to turbulent normal fluid flow, there is a dramatic increase in the homogeneity of the tangle, which could be used as an indirect measure of the transition to turbulence in the normal fluid component for experiments

Data science methods for comprehensive assessment of regional economic development

The paper deals with the assessment of the socio-economic development of Ukrainian regions using Data Science methods and multidimensional analysis, including taxonomy, n-dimensional classification, and ensemble decision trees methods. The methodological bases of economic regions development by the economic and mathematical modeling methods were investigated. The necessity of improving and further developing estimation models of the regional economic development using business analytics tools and multidimensional scaling methods was investigated. The ensemble decision trees methods was applied for the classification model of economic development of the Ukrainian regions according to the conceptual base of the research on regional economic development. It will increase the quality level of administrative decisions making on regional de-velopment asymmetry equalization. It is determined that in Ukraine, there is a significant imbalance of regions clusters with high and low economic level. Here was investigated the relationship between the two groups of economic development indicators – the indicators of the economic development regional performance and the group of economic potential. The results of the classification model allow identifying the set of indicators that have significant impact on the overall economic development. The developed ensemble model allows carrying out qualitative recognition and prediction of the state probability of economic development. It will improve the quality of decision making processes on equalization of regional development asymmetry. The further research gives the possibility to develop the system of levers directions of regional development imbalance equalization, to determine priority vectors of sustainable development of both the regions and the countr

A study of the electric response of He II at the excitation of second sound waves

We report an experimental investigation of the electric response of superfluid helium. Our results confirm the presence of electric potential that appears at the relative oscillatory motion of normal fluid and superfluid components in helium generated by the heater. The resonance of the electric potential was observed in the first four harmonics. A suggested method for the detection of the electric response allows the required resonance peak to be distinguished from spurious signals. Our results are in qualitative agreement with the data published by previous researchers. The reasons for the discrepancy in the measured values of the potential difference are discussed

Modelling of the Process of Regional systems’ Development Imbalances Aligning with the Use of Tax Levers Моделирование процесса выравнивания диспропорций развития региональных систем с использованием налоговых рычагов

The article is devoted to the question of social-economic development regions disproportions. The complex of economic-mathematical models of disproportions development leveling of regions, based on tax levers, was provided.В статье рассмотрены вопросы диспропорций социально-экономического развития регионов. Предложен комплекс экономико-математических моделей выравнивания диспропорций развития региональных систем на базе налоговых рычагов

Probing of quantum turbulence with the emitting vortex loops

The statistics of vortex loops emitted from the domain with quantum turbulence is studied. The investigation is performed on the supposition that the vortex loops have the Brownian or random walking structure with the generalized Wiener distribution. The main goal is to relate the properties of the emitted vortex loops with the parameters of quantum turbulence. The motivation of this work connected with recent studies, both numerical and experimental, on study of emitted vortex loops. This technique opens up new opportunities to probe superfluid turbulence. We demonstrated how the statistics of emitted loops is expressed in terms of the vortex tangle parameters and performed the comparison with numerical simulations.\newline PACS number(s): 67.25.dk, 47.37.+qComment: 5 pages 1 figur

Risk factors for recurrence of external genital endometriosis after surgical treatment: prospective cohortant study

Objectives of the study: improve early non-invasive diagnosis of external genital endometriosis (EGE) using the mass spectrometry method, and determine the risk factors for recurrence of EGE after surgical treatment. Material and methods: a prospective cohort study included 100 patients with EGE who underwent surgical treatment during the 2014 to 2016 period. The EGE diagnosis was made on the basis of diagnostic and therapeutic laparoscopic findings and finally confirmed at histological exam. All patients underwent blood sampling before and after surgical treatment to detect recurrence of endometriosis using direct mass spectrometry method. Results: recurrences of EGE were diagnosed in 22% of patients at 18–36 months postoperatively. High incidence of recurrent EGE was reported in the group of patients who did not receive post-surgical hormonal therapy. The hormone therapy with dienogest 2 mg for 6-9 months, as well as with goserelin 3.6 mg for 3-6 months showed the greatest efficacy for the prevention of recurrent EGE. Significant predictive factors of recurrence after surgical treatment for EGE include intensive acyclic pelvic pain; presence of surgical interventions for the history of EGE; infertility; stimulation of ovulation with hormonal drugs as part of the Assisted Reproductive Technologies Program; degree 3-4 disease spread; pronounced adhesions of the small pelvis; infiltrative forms of endometriosis; endometrioid cysts of large size; bilateral ovarian lesions. The plasma lipid profile including determination of phosphatidylcholines, phosphoethanolamines, diglyceride and sphingomyelin in the patients with endometriosis provides an approach for noninvasive early diagnosis of recurrence of this disease by mass spectrometry (sensitivity 93%, specificity 95%). Conclusion: This study developed an individual comprehensive approach to the prevention of recurrent EGE, including surgical treatment, hormonal therapy and diagnosis of the disease at an early stage of development. Timely administration of a-GnRH or dienogest 2 mg at the post-surgery stage is associated with a minimal or total absence of recurrent EGE. The administration of COCs showed no efficacy in preventing the recurrence of EGE, and therefore COCs cannot be recommended as a prophylactic drug, but exclusively for contraceptive use