Significance of intaoperative duplex ultrasonography at the endovascular interventions on the lower limb arteries

The article presents the results of intraoperative duplex ultrasonography (DUS) at the endovascular interventions (EV) in patients with occlusive-stenotic injuries of lower limb arteries. 48 segments of planned endovascular interventions (30 superficial femoral arteries and 18 popliteal arteries) were examined with use of common methods on ultrasound portable devise Unison 2-03 with 7,5 MHz linear sensor at all stages of endovascular treatment. The evaluation of hemodynamic indices of blood flow such as peak systolic velocity (PSV), ending diastolic velocity (Ved), medium, velocity of blood flow (Vm), resistivity index (RI), pulsatility index (PI), systole/diastole ratio (S/D) and. degree of stenosis of femoral-popliteal segment arteries before, during and. after X-ray-endovascular interventions was carried out. At intraoperative ultrasound duplex scanning patients had. significant (р < 0,001) decrease if PSV, Ved, Vm. and. the degree of stenosis in comparison with the results of the research before endovascular interventions. Also we registered significant (р < 0,001) decrease of PSV, Ved, Vm. and. the degree of stenosis in patients at ultrasound duplex scanning after endovascular interventions in comparison with the results of the research before operative treatment. There were no significant differences between those indices at ultrasound duplex scanning during and. after endovascular interventions. It was showed that evaluation of condition of lower extremities arteries during ballon angioplasty and. stenting with use of ultrasound duplex scanning allowed, to plan optimum volume and. to improve the results of endovascular operation in each patient individually. At that restoring of geometry and. artery lumina, accuracy of stent positioning, full compliance of stent diameter and. artery in problem zone, absence of stenosis at all or presence of residual stenosis < 25 % and. restoring of main blood flow without local increases of blood flow velocity were the criteria of successful endovascular interventions on femoral-popliteal segment arteries

A review of simulation and modeling approaches in microbiology

Bacterial communities are tightly interconnected systems consisting of numerous species making it challenging to analyze their structure and relations. There are several experimental techniques providing heterogeneous data concerning various aspects of this object. A recent avalanche of metagenomic data challenges not only biostatisticians but also biomodelers, since these data are essential to improve the modeling quality while simulation methods are useful to understand the evolution of microbial communities and their function in the ecosystem. An outlook on the existing modeling and simulation approaches based on different types of experimental data in the field of microbial ecology and environmental microbiology is presented. A number of approaches focusing on a description of such microbial community aspects as its trophic structure, metabolic and population dynamics, genetic diversity as well as spatial heterogeneity and expansion dynamics is considered. We also propose a classification of the existing software designed for simulation of microbial communities. It is shown that although the trend for using multiscale/hybrid models prevails, the integration between models concerning different levels of biological organization of communities still remains a problem to be solved. The multiaspect nature of integration approaches used to model microbial communities is based on the need to take into account heterogeneous data obtained from various sources by applying high-throughput genome investigation methods

Inferring possible magnetic field strength of accreting inflows in EXor-type objects from scaled laboratory experiments

Aims. EXor-type objects are protostars that display powerful UV-optical outbursts caused by intermittent and powerful events of magnetospheric accretion. These objects are not yet well investigated and are quite difficult to characterize. Several parameters, such as plasma stream velocities, characteristic densities, and temperatures, can be retrieved from present observations. As of yet, however, there is no information about the magnetic field values and the exact underlying accretion scenario is also under discussion. Methods. We use laboratory plasmas, created by a high power laser impacting a solid target or by a plasma gun injector, and make these plasmas propagate perpendicularly to a strong external magnetic field. The propagating plasmas are found to be well scaled to the presently inferred parameters of EXor-type accretion event, thus allowing us to study the behaviour of such episodic accretion processes in scaled conditions. Results. We propose a scenario of additional matter accretion in the equatorial plane, which claims to explain the increased accretion rates of the EXor objects, supported by the experimental demonstration of effective plasma propagation across the magnetic field. In particular, our laboratory investigation allows us to determine that the field strength in the accretion stream of EXor objects, in a position intermediate between the truncation radius and the stellar surface, should be of the order of 100 G. This, in turn, suggests a field strength of a few kilogausses on the stellar surface, which is similar to values inferred from observations of classical T Tauri stars

Russian features of health care reform in the current socio-economic conditions

The article examines the social, economic and financial components of health care reform. By analyzing the data from the surveys service of special communication and information FSO of Russia and the Fund «Public opinion» investigated people’s satisfaction with functioning of healthcare markets. Basic premise of health care reform and planned measures of state regulation of the sphere

Properties of Whistler Waves’ Ducting in Plasmas With Systems of Small‐Scale Density Depletions

International audienceAbstract The ducting of whistler waves by systems of small‐scale field‐aligned plasma density depletions is studied. Similarly to our previous paper (Zudin et al., 2019, https://doi.org/10.1029/2019ja026637 ), we carry out analytical calculations and numerical simulations for the parameters of an active experiment in which very low frequency whistler waves emitted by a ground‐based transmitter at a frequency of 18 kHz were received onboard the DEMETER satellite at 700 km above the SURA heating facility. Random‐sized density depletions with a level around 10%–20% and perpendicular sizes ranging from 10 m up to about 300 m are considered. The properties of ducted waves are determined by the perpendicular size of individual depletions. Particularly, depletions with a width of more then d 0 ∼ 100 m form separate ducting structures, that is, coupled waveguides capable of exchanging energy by means of mode overlap. Depletions with a width of less than d 0 ∼ 100 m form a common waveguide structure, whose properties are equivalent to those of a wider irregularity with a smoothed density profile. Two important differences are revealed in ducting properties of density depletions compared to density enhancements considered in Zudin et al. (2019, https://doi.org/10.1029/2019ja026637 ). First, depletions support highly oblique Gendrin mode waves, rather than quasi‐longitudinal whistlers as in the case of density enhancements. Second, the characteristic perpendicular size d 0 ∼ 100 m of density depletions separating the regimes of “coupled waveguides” and of “equivalent ducting structure” with smoothed density profile is by an order of magnitude smaller than for density enhancements of the same 10–20% relative level