ИЗУЧЕНИЕ ВОЗМОЖНОСТИ РЕГУЛЯЦИИ АНГИОГЕНЕЗА IN VITRO С ПОМОЩЬЮ РЕКОМБИНАНТНЫХ ФРАГМЕНТОВ ИНГИБИТОРОВ АНГИОГЕНЕЗА ЭНДОСТАТИНА, ТУМСТАТИНА И PEDF

Neovascular diseases of visual organ such as age-related macular degeneration, retinopathy of prematurity, diabetic retinopathy, thrombosis of central retina vein and its branches, neovascular glaucoma, choroid and retina tumors have the leading positions in the list of ophtalmopatologies that result in blindness and incapacity. The variety of angiostatic medications of applied ophtalmology is scant. The aim of work was to study the possibile approaches to angiogenesis regulation in vitro with the help of recombinant fragments of natural inhibitors of angiogenesis such as endostatin, tumstatin and PEDF (pigment epithelial derived factor), and also their ability to be the base of potentially feasible and pharmacologically active substances. It is determined that endostatin, tumstatin and PEDF, as well as the comparison medication Bevacizumab in vitro have pro- or antiangiogenic influence. The direction of the biological effect depends on the cultivation conditions, peptide concentration in the cultural fluid and stage of angiogenesis. Неоваскулярные заболевания органа зрения, такие как возрастная макулярная дегенерация, ретинопатия недоношенных, диабетическая ретинопатия, тромбозы центральной вены сетчатки и ее ветвей, неоваскулярная глаукома, опухоли хориоидеи и сетчатки, занимают лидирующие позиции в перечне офтальмопатологии, приводящей к слепоте и инвалидизации, а также к социальной и психологической дезадаптации. Арсенал ангиостатических препаратов в практической офтальмологии скуден. Цель настоящей работы заключалась в изучении возможности регуляции ангиогенеза in vitro с помощью рекомбинантных фрагментов природных ингибиторов ангиогенеза эндостатина, тумстатина и PEDF (pigment epithelial derived factor) и применения их в качестве потенциально возможных фармакологически активных субстанций. Установлено, что in vitro эндостатин, тумстатин и PEDF, как и препарат сравнения бевацизумаб, оказывают про- или антиангиогенное действие. Направленность биологического эффекта зависит от условий культивирования, концентрации пептида в культуральной жидкости и этапа ангиогенеза.

Hamiltonian BFV-BRST theory of closed quantum cosmological models

We introduce and study a new discrete basis of gravity constraints by making use of harmonic expansion for closed cosmological models. The full set of constraints is splitted into area-preserving spatial diffeomorphisms, forming closed subalgebra, and Virasoro-like generators. Operatorial Hamiltonian BFV-BRST quantization is performed in the framework of perturbative expansion in the dimensionless parameter which is a positive power of the ratio of Planckian volume to the volume of the Universe. For the (N+1) - dimensional generalization of stationary closed Bianchi-I cosmology the nilpotency condition for the BRST operator is examined in the first quantum approximation. It turns out, that certain relationship between dimensionality of the space and the spectrum of matter fields emerges from the requirement of quantum consistency of the model.Comment: 28 pages, LaTe

Magnetic field induced softening of spin waves and hard axis order in the Kondo lattice ferromagnet CeAgSb2

A significant number of Kondo lattice ferromagnets order perpendicular to the easy magnetization axis dictated by the crystalline electric field. The nature of this phenomenon has attracted considerable attention, but remains poorly understood. In the present paper we use inelastic neutron scattering supported by magnetization and specific heat measurements to study the spin dynamics in the hard axis ferromagnet CeAgSb2. In the zero field state we observed two sharp magnon modes, which are associated with Ce ordering and extended up to amp; 8776;3 meV with a considerable spin gap of 0.6 meV. Application of a magnetic field perpendicular to the moment direction reduces the spectral intensity and suppresses the gap and significantly enhances the low temperature specific heat at a critical field of Bc amp; 8776;2.8 T via a mean field like transition. Above the transition, in the field polarized state, the gap eventually reopens due to the Zeeman effect. We modeled the observed dispersion using linear spin wave theory taking into account the ground state amp; 915;6 doublet and exchange anisotropy. Our model correctly captures the essential features of the spin dynamics including magnetic dispersion, distribution of the spectral intensity, as well as the field induced behavior, although several minor features remain obscure. The observed spectra do not show significant broadening due to the finite lifetime of the quasiparticles. Along with a moderate electronic specific heat coefficient amp; 947; 46 mJ mol K2 this indicates that the Kondo coupling is relatively weak and the Ce moments are well localized. Altogether, our results provide profound insight into the spin dynamics of the hard axis ferromagnet CeAgSb2 and can be used as solid ground for studying magnetic interactions in isostructural compounds including CeAuSb2, which exhibits nematicity and unusual mesoscale magnetic texture

Localized states in 2D semiconductors doped with magnetic impurities in quantizing magnetic field

A theory of magnetic impurities in a 2D electron gas quantized by a strong magnetic field is formulated in terms of Friedel-Anderson theory of resonance impurity scattering. It is shown that this scattering results in an appearance of bound Landau states with zero angular moment between the Landau subbands. The resonance scattering is spin selective, and it results in a strong spin polarization of Landau states, as well as in a noticeable magnetic field dependence of the $g$ factor and the crystal field splitting of the impurity $d$ levels.Comment: 12 pages, 4 figures Submitted to Physical Review B This version is edited and updated in accordance with recent experimental dat

Von Bezold assimilation effect reverses in stereoscopic conditions

Lightness contrast and lightness assimilation are opposite phenomena: in contrast, grey targets appear darker when bordering bright surfaces (inducers) rather than dark ones; in assimilation, the opposite occurs. The question is: which visual process favours the occurrence of one phenomenon over the other? Researchers provided three answers to this question. The first asserts that both phenomena are caused by peripheral processes; the second attributes their occurrence to central processes; and the third claims that contrast involves central processes, whilst assimilation involves peripheral ones. To test these hypotheses, an experiment on an IT system equipped with goggles for stereo vision was run. Observers were asked to evaluate the lightness of a grey target, and two variables were systematically manipulated: (i) the apparent distance of the inducers; and (ii) brightness of the inducers. The retinal stimulation was kept constant throughout, so that the peripheral processes remained the same. The results show that the lightness of the target depends on both variables. As the retinal stimulation was kept constant, we conclude that central mechanisms are involved in both lightness contrast and lightness assimilation

Large-scale power in the CMB and new physics: An analysis using Bayesian model comparison

Published versio

Measurement of the near-threshold e+e−→DDˉe^+e^- \to D \bar D cross section using initial-state radiation

We report measurements of the exclusive cross section for $e^+e^- \to D \bar D$, where $D=D^0$ or $D^+$, in the center-of-mass energy range from the $D \bar D$ threshold to $5\mathrm{GeV}/c^2$ with initial-state radiation. The analysis is based on a data sample collected with the Belle detector with an integrated luminosity of 673 $\mathrm{fb}^{-1}$.Comment: Presented at EPS07 and LP07 conferences, published in PRD(RC

Study of charmonia in four-meson final states produced in two-photon collisions

We report measurements of charmonia produced in two-photon collisions and decaying to four-meson final states, where the meson is either a charged pion or a charged kaon. The analysis is based on a 395fb^{-1} data sample accumulated with the Belle detector at the KEKB electron-positron collider. We observe signals for the three C-even charmonia eta_c(1S), chi_{c0}(1P) and chi_{c2}(1P) in the pi^+pi^-pi^+pi^-, K^+K^-pi^+pi^- and K^+K^-K^+K^- decay modes. No clear signals for eta_c(2S) production are found in these decay modes. We have also studied resonant structures in charmonium decays to two-body intermediate meson resonances. We report the products of the two-photon decay width and the branching fractions, Gamma_{gamma gamma}B, for each of the charmonium decay modes.Comment: 22 pages, 12 figure

Observation of the ϕ(1680)\phi(1680) and the Y(2175) in e+e−→ϕπ+π−e^+ e^- \to \phi\pi^+\pi^-

The cross sections for $e^+ e^- \to \phi\pi^+\pi^-$ and e^+ e^- \to \phi \fzero are measured from threshold to $\sqrt{s}=3.0$ $\hbox{GeV}$ using initial state radiation. The analysis is based on a data sample of 673 fb$^{-1}$ collected on and below the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. First measurements are reported for the resonance parameters of the $\phi(1680)$ in the $\phi\pi^+\pi^-$ mode: $m=(1689\pm 7\pm 10)$ MeV/$c^2$ and $\Gamma=(211\pm 14\pm 19)$ MeV/$c^2$. A structure at $\sqrt{s}=2.1 \hbox{GeV}/c^2$, corresponding to the so called Y(2175), is observed; its mass and width are determined to be $2079\pm13^{+79}_{-28}$ MeV/$c^2$ and $192\pm23^{+25}_{-61} \hbox{MeV}/c^2$, respectively.Comment: 11 pages, 6 figures. Add one plot. Accepted by Phys.Rev.D(RC

Search for B -> h(*) nu nubar Decays at Belle

We present a search for the rare decays B -> h(*) nu nubar, where h(*) stands for a light meson. A data sample of 535 million BBbar pairs collected with the Belle detector at the KEKB e+e- collider is used. Signal candidates are required to have an accompanying B meson fully reconstructed in a hadronic mode and signal-side particles consistent with a single h(*) meson. No significant signal is observed and we set upper limits on the branching fractions at 90% confidence level. The limits on B0 -> K*0 nu nubar and B+ -> K+ nu nubar decays are more stringent than the previous constraints, while the first searches for B0 -> K0 nu nubar, pi0 nu nubar, rho0 nu nubar, phi nu nubar and B+ -> K*+ nu nubar, rho+ nu nubar are reported.Comment: 6 pages, 2 figures, submit to PR