Analysis of Peculiarities of the Stellar Velocity Field in the Solar Neighborhood

Based on a new version of the Hipparcos catalogue and an updated Geneva-Copenhagen survey of F and G dwarfs, we analyze the space velocity field of about 17000 single stars in the solar neighborhood. The main known clumps, streams, and branches (Pleiades, Hyades, Sirius, Coma Berenices, Hercules, Wolf 630-alpha Ceti, and Arcturus) have been identified using various approaches. The evolution of the space velocity field for F and G dwarfs has been traced as a function of the stellar age. We have managed to confirm the existence of the recently discovered KFR08 stream. We have found 19 Hipparcos stars, candidates for membership in the KFR08 stream, and obtained an isochrone age estimate for the stream, 13 Gyr. The mean stellar ages of the Wolf 630-alpha Ceti and Hercules streams are shown to be comparable, 4--6 Gyr. No significant differences in the metallicities of stars belonging to these streams have been found. This is an argument for the hypothesis that these streams owe their origin to a common mechanism.Comment: 23 pages, 9 figure

Modeling of the high-resolution optical-coherence diagnostics of bi-refringent biological tissues

We present a computer model of the polarization-sensitive interference diagnostics of the bi-refringent biological media, with a particular example of the lamella of eye cornea. The diagnostic procedure employs the modified Mach–Zehnder interferometer with controllable phase retardation of the reference wave, separate observation of the orthogonal linearly-polarized interference signals, and evaluation of the phases and amplitudes of their variable (AC) components. The data obtained permit to determine the mean refractive index as well as the difference between the extraordinary and ordinary refractive indices, which, in turn, indicates the optical axis and the collagen fibers’ orientation in the lamella. The modelled procedure enables the sample structure diagnostics with the longitudinal and lateral resolution ∼100 nm and ∼1.8 μm, correspondingly. In particular, it permits a reliable detection and quantitative characterization of a thin (<100 nm) near-surface layer where the mean refractive index differs by less than 1% from that in the main volume (due to the different orientation of the collagen fibers). The diagnostic approach, developed in the paper, can be useful in various problems of structure characterization of optically-anisotropic biological tissues

Galactic Kinematics from OB3 Stars with Distances determined from Interstellar Ca II Lines

Based on data for 102 OB3 stars with known proper motions and radial velocities, we have tested the distances derived by Megier et al. from interstellar Ca II spectral lines. The internal reconciliation of the distance scales using the first derivative of the angular velocity of Galactic rotation {\Omega}'0 and the external reconciliation with Humphreys's distance scale for OB associations refined by Mel'nik and Dambis show that the initial distances should be reduced by \approx 20%. Given this correction, the heliocentric distances of these stars lie within the range 0.6-2.6 kpc. A kinematic analysis of these stars at a fixed Galactocentric distance of the Sun, R0=8 kpc, has allowed the following parameters to be determined:(1) the solar peculiar velocity components (U_o,V_o,W_o)=(8.9,10.3,6.8)\pm(0.6,1.0,0.4) km/s;(2) the Galactic rotation parameters {\Omega}_o=-31.5\pm0.9 km/s/kpc, {\Omega}'_o=+4.49\pm0.12 km/s/kpc^2, {\Omega}"_o=-1.05\pm0.38 km/s/kpc^3, (the corresponding Oort constants are A=17.9\pm0.5 km/s/kpc, B=-13.6\pm1.0 km/s/kpc and the circular rotation velocity of the solar neighborhood is |V_o|=252\pm14 km/s); (3) the spiral density wave parameters, namely: the perturbation amplitudes for the radial and azimuthal velocity components, respectively, f_R = -12.5\pm1.1 km/s and f_{\theta}=2.0\pm1.6 km/s; the pitch angle for the two-armed spiral pattern i=-5.3\pm0.3 degrees, with the wavelength of the spiral density wave at the solar distance being {\lambda}=2.3\pm0.2 kpc; the Sun's phase in the spiral wave {\chi}_o=-91\pm4 degrees.Comment: 14 pages, 4 figures, 3 table

Соединение пластин кремния стеклообразным нанокомпозитом, формируемым золь-гель методом

   Разработан состав стеклообразующей композиции и лабораторная золь-гель технология соединения с ее помощью пластин монокристаллического кремния для создания структур «кремний – изолятор – кремний». Показана возможность снижения температуры формирования качественного соединительного слоя до 1000–1100 °С. Полученные с применением разработанного золь-гель метода стеклокомпозиции могут быть использованы в технологических процессах, требующих формирования неразъемных соединений кремниевых пластин.   We have herein developed a glass-forming composition and the related sol-gel technology for bonding monocrystalline silicon wafers to produce «silicon–insulator–silicon» structures. A possibility to fabricate defect-free glass-like bonding layers at the annealing temperature decreased to 1000–1100 °C is demonstrated. The composites obtained by the sol-gel method can be used in technological processes of formation of the solid compound of silicon wafers.   Разработан состав стеклообразующей композиции и лабораторная золь-гель технология соединения с ее помощью пластин монокристаллического кремния для создания структур «кремний – изолятор – кремний». Показана возможность снижения температуры формирования качественного соединительного слоя до 1000–1100 °С. Полученные с применением разработанного золь-гель метода стеклокомпозиции могут быть использованы в технологических процессах, требующих формирования неразъемных соединений кремниевых пластин

Comparative study of the cytotoxic properties of isatin-containing derivatives of 4-thiazolidinone with different structure toward human tumor cells in vitro

Compounds on the basis of 4-thiazolidinone and its isatin-containing derivatives are characterized by a broad spectrum of biological activities and are potential antineoplastic agents. We have shown that the combination of 4-thiazolidinone and isatine (1H-indole-2,3-dione) in one molecule enhances the cytotoxic action of novel compounds towards lukemic and carcinoma cells in vitro. The level of cytotoxic action of ID-3833, ID-4522, ID-4523, ID-4524, ID-4525, ID-4526, ID-4527 compounds strongly depends on the presence of a halogen in the 5th position of the indoline moiety and the type of the atom (chlorine or bromine) in the aryl groups in the 3rd and 5th positions in pyrazoline moiety. Compound ID-3833 demonstrates the highest activity, which can be associated with the presence of bromine in the 5th position of indoline and 4-methoxyphenyl in the 5th position of pyrazoline and naphthyl in the 3rd position of pyrazoline. ID-4524 compound, whose molecule contains 5-bromindoline and two para-chlorophenyl groups also possessed high cytotoxic effect towards tumor cells. At the same time, ID-4522 compound was found to possess the lowest cytotoxic activity towards tumor cells. Like ID-4524 compound, it is characterized by the presence of two para-chlorophenyl groups in 3rd and 5th position of pyrazoline in isatin-pyrazoline-thiazolidinonr system, but it does not contain halogen in the 5th position of the indoline moiety. Thus, cytotoxic effect of isatin-containing 4-thiazolidinones mostly depends on the presence of halogen in the 5th position of the indoline, and the type of halogen in the 3rd and 5th position of the aryl groups of pirazoline cycle. All of these substances induce apoptosis in tumor cells. It has been shown that the ID-3833 substance induces apoptosis of mixed type, which includes the ER stress and mitochondrial apoptosis. The identified structure-functional relationships of 4-thiazolidones will be of high importance for further enhancement of their antineoplastic activity towards tumor cells