Superconducting properties of nanostructured microhelices

Superconducting micro- and nanohelices are proposed for the first time. A theoretical investigation of the superconducting state in the helical coils at the micro- and nanoscale is performed within the time-dependent Ginzburg-Landau approach. The pattern and number of vortices in a stationary distribution are determined by their confinement to the ultrathin helical coil and can therefore be efficiently controlled by the spiral stripe width and the spiral pitch distance for both dense and sparse coils. Quasi-degeneracy of vortex patterns is manifested in the helical coil when the number of vortices is incommensurable with the total number of half-turns. With increasing radius, superconducting helical coils provide a physical realization of a transition from the vortex pattern peculiar to an open tube to that of a planar stripe.

[Size of viable myocardium and collateral blood flow in patients with coronary artery occlusion]

The aim of the study was to investigate correlation between collateral blood flow to occluded coronary vessel and the size of viable myocardium in the area fed by that artery. Total 295 patients with coronary artery occlusion were divided into 2 groups. The 1st group included 193 patients with the history of Q-wave myocardial infarction (MI), the 2nd group - 102 patients with non-Q-wave MI or without MI. Left ventriculography evidenced lesser volume of viable myocardium in the 1st group compared with the 2nd. All patients were assessed for collateral blood flow (CBF) to occluded vessel. There was significantly higher incidence of minor (grade I) or absent (grade 0) CBF in the 1st group - 71 (36.9%) and 10 (5.1%) cases, respectively - compared with the 2nd group - 15 (14.7%) and 0 (0%) cases, respectively (p<0.05). Unlike this, satisfactory (grade II) and good (grade III) CBF to distal segments of occluded artery was more frequent in the 2nd group - 71 (69.6%) and 16 (15.7%) cases, respectively, compared with the 1st group - 102 (52.9%) and 10 (5.1%) cases, respectively (p<0.05). The authors conclude that evaluation of CBF level can complement the assessment of viable myocardium in the occluded coronary artery area, and the presence of the II-III grade CBF can support the necessity of occluded vessel angioplasty.

[Acute diffuse thrombosis of left coronary artery complicating coronary angioplasty]

The paper presents a case report for successful treatment of acute diffuse thrombosis developed in left coronary artery after coronary angioplasty fulfilled for 39-year-old patient with acute coronary syndrome. Heparin resistance accompanied by intracoronary intervention triggered severe ascending thrombosis of the whole anterior descending artery with involvement of circumflex artery ostium. Therapeutic measures included: repeated Heparin bolus injection (total 27,000 U), bolus intracoronary Streptokinase injection (500,000 U) with subsequent Streptokinase infusion (1,000,000 U in 1 hour), stenting of circumflex artery ostium for thrombus mechanical destruction. This enabled us to restore adequate coronary flow and to resolve critical condition with minimal loss (periprocedural complication - repeated non-Q wave myocardial interfaction).