Current driven tri-stable resistance states in magnetic point contacts.

Point contacts between normal and ferromagnetic metals are investigated using magnetoresistance and transport spectroscopy measurements combined with micromagnetic simulations. Pronounced hysteresis in the point contact resistance versus both bias current and external magnetic field are observed. It is found that such hysteretic resistance can exhibit, in addition to bi-stable resistance states found in ordinary spin valves, tri-stable resistance states with a middle resistance level.

Surface spin-valve effect.

We report an observation of spin-valve-like hysteresis within a few atomic layers at a ferromagnetic interface. We use phonon spectroscopy of nanometer-sized point contacts as an in situ probe to study the mechanism of the effect. Distinctive energy phonon peaks for contacts with dissimilar nonmagnetic outer electrodes allow localizing the observed spin switching to the top or bottom interfaces for nanometer thin ferromagnetic layers.

[Lymphocyte metabolism in patients with acute pancreatitis with different genotypes of GSTM1 and GSTT1 genes].

In this study, we have investigated correlation between enzymatic activity of NAD(P)-dependent dehydrogenases of lymphocytes and polymorphic variants of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) genes in the group of unrelated patients with acute pancreatitis in comparison with healthy Russians from Krasnoyarsk. Thus, genotype GSTM1 0/0 is the marker of predisposition to the acute pancreatitis, wheras polymorphism of the GSTT1 gene is not involved in the development of the pancreatitis, at least in our group. The bioluminescence analysis showed statistically significant decrease of the levels of G3PD, NAD(+)MDH and the increase of NADH(+)LDH, NAD(+)GDH, NADH(+)GDH in lymphocytes of pancreatic group.

Spectroscopy of phonons and spin torques in magnetic point contacts.

Phonon spectroscopy is used to investigate the mechanism of current-induced spin torques in nonmagnetic/ferromagnetic (N/F) point contacts. Magnetization excitations observed in the magneto-conductance of the point contacts are pronounced for diffusive and thermal contacts, where the electrons experience significant scattering in the contact region. We find no magnetic excitations in highly ballistic contacts.

Analysis of 5-nitrofuran derivatives in biological objects.

Original methods for identification and quantitative photometry of 5-nitrofurane derivatives based on the use of known rhodanine reagents were developed and used in clinical analysis.