Motion of stars near the galactic center

n/

Analysis of dark matter profiles in the halos of spiral galaxies

The distribution of dark matter in the low surface brightness spiral galaxies U5750, U11454, U11819, and U11648 is analyzed by utilizing well-established density profiles from existing literature. These profiles include the Beta, Brownstein, Burkert, exponential sphere, pseudo-isothermal, and Persic profiles. For simplicity, we assume spherically symmetric distribution of dark matter in the considered galaxies, without accounting for their intricate structural complexities. For each density profile, we fit the rotation curve data to the aforementioned galaxies. Employing Markov Chain Monte Carlo statistical analyses, we infer model-free parameters from the rotation curves, namely the characteristic (central) density and scale radius. This enables us to estimate the total dark matter mass within the galactic halos. To identify the best-fit profile, we employ the Bayesian Information Criterion. Additionally, we adopt the Levenberg-Marquardt nonlinear least squares approach for the purpose of comparison and completeness. Through our statistical analysis, we offer a physical interpretation behind the selection of specific profiles. This interpretation is based on the insights obtained from the analyses

Algorithm of investigation for choosing repeated surgery on aorta and arteries of the lower extremities

Aim: to estimate the diagnostic capabilities of ultrasound and angiographic methods in evaluation of the vascular bed in patients with occlusion and stenosis of arteries of lower extremities. The results of clinical investigation of 108 patients with relapse of chronic critical ischemia of lower extremities after reconstructive operations were analyzed. All patients were clinically and laboratory examined, the condition of the arterial system investigated by continuous wave Doppler (CW Doppler), color duplex scanning, X-ray angiography, magnetic resonance angiography, computed tomography, three-dimensional computed tomography in three-dimensional reconstruction. In 44 patients, an objective cause of thrombosis in re-development areas and relapse of chronic critical ischemia of lower limbs was detected. Based on the survey re Reconstructive surgery for each patient was elaborated. The optimal methods of preoperative diagnosis of complex lesions in lower limb arteries are Dopplerography, duplex scanning of main arteries, arteries of the foot, toes and angiography

Repeated multi intervention on aorta and arteries of the lower extremities

The article presents the results of the survey and treatment of 108 patients admitted with the clinical relapse of chronic critical ischemia of lower extremities that arose at different times after the primary reconstructive operations. In a special survey of patients revealed that 40.7% of cases there was an objective reason for the development of postoperative complications and recurrence of critical ischemia. All patients were operated on again in the light of the identified causes, preventive measures taken by the development of complications. Obtained good results - in 78,7% of cases arterial blood flow restored. The optimal method of repeated reconstructive interventions depending on the cause of relapse of chronic critical limb ischemia, developed indications and methods of combined treatment with the development of postoperative complications after the primary reconstructive interventions. It performs the following operations: resection of abdominal aortic aneurysm, aorto-bifemoralnoe prosthetics, multilevel bypass limb, femoral-tibial artery bypass technique «in situ», thrombectomy and autogenous vein anastomosis and profundoplasty