DIFFERENTIAL DIAGNOSIS OF RADICULOPATHY IN LYME BORRELIOSISAND DYSTROPHIC LESIONS OF THE VERTEBRAL COLUMN

Subjects and methods. Thirty patients, including 9 (30.0%) men and 21 (70.0%) women, with signs of radiculopathy (RP) in late-stages Lyme borreliosis (LB) were examined. A control group comprised 30 patients with vertebrogenic RP in the presence of dystrophic changes in the vertebral column. Results. 56.7% of the patients with LB were observed to have its primary chronic course in the absence of the acute period of LB. The latter with the signs of RP showed a topic association between the pain location and the tick bite site in 43.3% of the patients. A gradual disease development was more frequently (63.3%) observed in LB while the periods of remission and exacerbation were more typical (56.7%) in vertebrogenic RP. In the patients with LB, pain syndrome depended on posture and physical exercise less frequently (30.0%) than in those with vertebrogenic RP (96.7%). Bilateral pain irradiation was more characteristic of RP in LB than in dystrophic lesions of the vertebral column. The symptoms of tonic muscle tension and limited movement volume in the afflicted part of the vertebral column were significantly less common in the patients with LB than in those with vertebrogenic RP. LB was marked by a concomitance of radicular and polyneuritic disorders (83.3%) and vertebrogenic RP was characterized by a preponderance of the radicular-type of sensitivity disorder (100%). Systemic inflammatory syndrome and polysystemacy of manifestations were more characteristic of LB. The benefits of nonsteriodal antiinflammatory drugs in LB patients with RP were significantly worse than in those with vertebrogenic RP; regression of symptoms in LB was seen only after a course of specific antibiotic therapy

On the Theory of Directional Solidification in the Presence of a Mushy Zone

Abstract: A model is developed for the directional solidification of a binary melt with a two-phase zone (mushy zone), where the fraction of the liquid phase is described by a space–time scaling relation. Self-similar variables are introduced and the interphase boundary growth is inversely proportional to the square root of time. The mathematical model of the process is reformulated using self-similar variables. Exact self-similar solutions of heat-and-mass transfer equations are determined in the presence of two mobile phase-transition boundaries, namely, solid–mushy zone and mushy zone–liquid ones. The temperature and impurity concentration distributions in the solid phase, the mushy zone, and the melt are found as integral expressions. A decrease in the dimensionless cooled-boundary temperature leads to an increase in the solidification rate and the fraction of the liquid phase. The solidification rate, the parabolic growth constants, and the fraction of the liquid phase at the solid–mushy zone boundary are determined depending on the scaling parameter and the thermophysical constants of the solidifying melt. The positions of the solid–mushy zone and mushy zone–binary melt phase transition boundaries are found. The dependences of the solidification rate (inversely proportional to the square root of time) are analyzed. The scaling parameter significantly is shown to substantially affect the solidification rate and the fraction of the liquid phase in the phase transformation region. The developed model and the method of its solution can be generalized to the case of directional solidification of multicomponent melts in the presence of several phase transformation regions (e.g., main and cotectic two-phase zones during the solidification of three-component melts). © 2021, Pleiades Publishing, Ltd.This work was supported by the Russian Foundation for Basic Research (project no. 18-58-00034 Bel_a) and the Belarussian Foundation for Basic Research (project no. F18R-195)

Aspects of clinical differential diagnosis of radiculopathy in Lyme disease and spondylosis

The goal of the present study was to determine significant diagnostic signs of radiculopathy in the late stage of Lyme disease (LD) and in spondylosis. The pain in patients with radiculopathy and LD was often localized in the place of tick-bite (in 25.5%). The insidious onset of the disease was more typical in LD (in 84.3%), in patients with spondylosis and radiculopathy remissions and exacerbations were typical (62.2%). Inflammatory syndrome, polysystemic changes were typical for LD. In LD the effect of NAIDs was rather poor, the patients improved after treatment with antibiotics