ABSTRACT
Two-dimensional electron systems in a quantizing magnetic field are regarded as of exceptional interest, considering the possible role of anyons-quasiparticles with non-boson and non-fermion statistics-in applied physics. To this day, essentially none but the fractional states of the quantum Hall effect (FQHE) have been experimentally realized as a system with anyonic statistics. In determining the thermodynamic properties of anyon matter, it is crucial to gain insight into the physics of its neutral excitations. We form a macroscopic quasi-equilibrium ensemble of neutral excitations - spin one anyon complexes in the Laughlin state ν = 1/3, experimentally, where ν is the electron filling factor. The ensemble is found to have such a long lifetime that it can be considered the new state of anyon matter. The properties of this state are investigated by optical techniques to reveal its Bose properties.
ABSTRACT
The purpose of the study was to investigate influence of glucosaminyl muramyl dipeptide (GMDP) and its derivatives on adenosine deaminase (ADA, CE 3.5.4.4.) and 5'-nucleotidase (5-N, CE 3.1.3.5) activity in murine macrophages in vitro. The intensity of superoxide radicals (O2-) formation by these cells has been also studied. GMDP incubated with macrophages was found to inhibit substantially the activity of 5-N, without affecting the activity of ADA in these cells. The maximal effect on 5-N activity was noted following 24 h of co-culture and was accompanied by a higher intensity of O2- formation. GMDP added in doses ranging from 0.01 to 1 microgram/ml induced a gradual decrease in 5-N activity, with an increase in activity of the O2- -generating system. The GMDP analog with double dipeptide link GM(DP)2 has demonstrated the same activating effect as GMDP. The presence of dipeptide alanyl-D-isoglutamine in the GMDP structure is necessary for realization of the drug activating effect, as N-acetylglucosaminyl-N-acetylmuramyl failed to influence macrophage activity. Neither D-D nor L-L isomers of the drug affect the 5-N activity and O2- formation in macrophages. The mechanism of macrophages activation induced by GMDP may include the inhibition of 5-N activity and the stimulation in production of superoxide radicals.
