The reactions of 1,1-dimethylhydrazine with 2,3,5-triphenyl-2
Н
-tetrazolium and 2,5-diphenyl-3-(4-nitrophenyl)-2
Н
-tetrazolium chlorides in a solution and on a cellulose carrier have been studied ...by means of spectrophotometry and chromato–mass spectrometry to develop new chromogenic indicators for detection of 1,1-dimethylhydrazine. 1,3,5-Triphenylformazan and 1,3-diphenyl-5-(4-nitrophenyl)formazan are formed in these reactions, respectively; deep red shifts have been observed. Other products of these reactions result from oligomerization and addition of short-living 1,1-dimethylhydrazyl and tetrazolium radicals.
In experiments on BALB/c mice, prediabetes was modeled by administration of streptozotocin in a dose of 130 mg/kg. DNA damage was assessed by the method of DNA comets. Noopept (0.5 mg/kg ...intraperitoneally) was administered for 14 days before and for 6, 13, or 14 days after streptozotocin administration. Despite moderate hyperglycemia and increased malondialdehyde level, the intensity of DNA damage in cells of the pancreas, liver, and kidneys significantly surpassed the control values. Noopept normalized these parameters due to its pronounced antigenotoxic effect. For both the damaging effect of streptozotocin and the normalizing effect of Noopept, DNA changes manifested mainly in terms of atypical DNA comets. Our findings confirm the role of DNA damage in the pathogenesis of diabetes. They indicate the possibility of pharmacological protection of pancreatic β cells with the neuroprotective drug and provide an important argument in favor of the hypothesis about the similarity of the mechanisms of formation of the resistance of neurons and β cells to the cytotoxic influences.
We overview our recent theoretical studies on nonlinear atom optics of the Bose-Einstein condensates (BECs) loaded into optical lattices. In particular, we describe the band-gap spectrum and ...nonlinear localization of BECs in one- and two-dimensional optical lattices. We discuss the structure and stability properties of spatially localized states (matter-wave solitons) in 1D lattices, as well as trivial and vortex-like bound states of 2D gap solitons. To highlight similarities between the behavior of coherent light and matter waves in periodic potentials, we draw useful parallels with the physics of coherent light waves in nonlinear photonic crystals and optically-induced photonic lattices.
We demonstrate an experimental approach for creating spatially localized states in a semiconductor microcavity laser. In particular, we shape the spatial gain profile of a quasi-one-dimensional ...microcavity laser with a nonresonant, pulsed optical pump to create spatially localized structures, known as gain-pinned dissipative solitons, that exist due to the balance of gain and nonlinear losses. We directly probe the ultrafast formation dynamics and decay of these localized structures, showing that they are created on a picosecond timescale, orders of magnitude faster than laser cavity solitons. All of the experimentally observed features and dynamics are reconstructed by numerical modeling using a complex Ginzburg–Landau model, which explicitly takes into account the carrier density dynamics in the semiconductor.
PDF
