Pharmacoprotective influences on different links of the mechanism underlying 6-hydroxydopamine-induced degeneration of nigro-striatal dopaminergic neurons

In this study we examined the possibility of preventing degeneration of dopaminergic nigro-striatal neurons caused in rats by a neurotoxin, 6-hydroxydopamine. We showed that an antioxidant, Trolox, an inhibitor of nitric oxide synthase, N_ω-nitro-L-arginine methyl ester, and an inhibitor of caspases, zinc chloride, are capable of preventing to a considerable extent the neurotoxin-induced apoptosis of dopaminergic neurons of the substantia nigra. Neirofiziologiya/Neurophysiology, Vol. 38, No. 2, pp. 150–156, March–April, 2006.     

Effect of the high-voltage electrode polarity and wire preheating on the energy characteristics of electric explosion of fine tungsten wires in vacuum

Results are presented from experiments on the explosion of 30.5-μm tungsten wires at a current density of up to 140 MA/cm² and resistive-heating time of 40–100 ns. The experiments were performed both with and without preheating of wires and at different polarities of the high-voltage electrode. The effect of plasma production at the electrodes on the initiation of breakdown along the exploding wire was investigated by using a frame camera. It is shown that, when the polarity of the high-voltage electrode is positive, breakdown begins with the formation of a bright spot on the wire surface near the cathode, whereas at the negative polarity, breakdown begins with the formation of bright spots on the cathode surface. A comparative analysis of the main characteristics of wire explosions is performed. It is shown that preheating of the conductor increases the resistive-heating time and, accordingly, the energy deposited in the wire core. This effect takes place during explosions of both single wires and wire arrays. The evolution of the state of a metal during the explosion (including melting and evaporation) is studied by one-dimensional simulations by using a semiempirical equation of state describing the properties of tungsten over a wide range of parameters.     

Preparation and isolation of dansyladenylates as fluorescent substrates in reactions of the energy metabolism

A method was developed for preparation of dansylated derivatives of adenine nucleotides characterized by fluorescence when being irradiated with UV-light. The involvement of dansylated ATP, ADP and AMP as substrate analogues in energy metabolism is demonstrated in the ATPase, hexokinase, pyruvate kinase and adenylate kinase reactions. The kinetics of the reactions is discussed.