Planet Consumption and Stellar Metallicity Enhancements

The evolution of a giant planet within the stellar envelope of a main-sequence star is investigated as a possible mechanism for enhancing the stellar metallicities of the parent stars of extrasolar planetary systems. Three-dimensional hydrodynamical simulations of a planet subject to impacting stellar matter indicate that the envelope of a Jupiter-like giant planet can be completely stripped in the outer stellar convection zone of a solar-mass star. In contrast, Jupiter-like and less massive Saturn-like giant planets are able to survive through the base of the convection zone of a 1.22 solar-mass star. Although strongly dependent on details of planetary interior models, partial or total dissolution of giant planets can result in significant enhancements in the metallicity of host stars with masses between about 1.0 and 1.3 solar masses. The implications of these results with regard to planetary orbital migration are briefly discussed.Comment: 11 pages, 2 figures, accepted for ApJ Letter

Extremely polysubstituted magnetic material based on magnetoplumbite with a hexagonal structure: Synthesis, structure, properties, prospects

Crystalline high-entropy single-phase products with a magnetoplumbite structure with grains in the µm range were obtained using solid-state sintering. The synthesis temperature was up to 1400 °C. The morphology, chemical composition, crystal structure, magnetic, and electrodynamic properties were studied and compared with pure barium hexaferrite BaFe 12 O 19 matrix. The polysubstituted high-entropy single-phase product contains five doping elements at a high concentration level. According to the EDX data, the new compound has a formula of Ba(Fe6Ga1.25In1.17Ti1.21Cr1.22Co1.15)O19. The calculated cell parameter values were a = 5.9253(5) Å, c = 23.5257(22) Å, and V = 715.32(9) Å3. The increase in the unit cell for the substituted sample was expected due to the different ionic radius of Ti/In/Ga/Cr/Co compared with Fe3+. The electrodynamicmeasurements were performed. The dielectric and magnetic permeabilities were stable in the frequency range from 2 to 12 GHz. In this frequency range, the dielectric and magnetic losses were??0.2/0.2. Due to these electrodynamic parameters, this material can be used in the design of microwave strip devices. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The work was supported by the Russian Science Foundation, project No. 18-73-10049

СОВРЕМЕННЫЕ ПРЕДСТАВЛЕНИЯ О КЛЕТОЧНО-МОЛЕКУЛЯРНЫХ МЕХАНИЗМАХ АНГИОГЕНЕЗА

The review contains modern scientific literary data, recently conducted studies, which devoted to studying of molecular, cellular and genetic mechanisms in processes of angiogenesis. The authors describe in detail angiogenesis stages, value of the main proangiogenic and antiangiogenic factors, apoptosis factors, which have different orientation in regulation of blood vessels development. Role of a special population of bone marrow-derived stem cells - endothelial progenitor cells (EPC) in the neovascularization is analyzed. Participation of VEGF-dependent, ANG/Tie-dependent and Notch-signaling pathways, posttranscription regulation of a genome with participation of microRNA in angiogenesis processes are discussed and reviewed.В обзоре представлены современные научные литературные данные, рассмотрены проведенные исследования, посвященные изучению молекулярных, клеточных и генетических механизмов в процессах ангиогенеза. Авторы детально анализируют этапы процесса ангиогенеза, роль ведущих проангиогенных и антиангиогенных факторов, факторов апоптоза, обладающих различной направленностью в регуляции развития кровеносных сосудов. Проводится подробный анализ роли особой популяция стволовых клеток костного мозга - предшественников эндотелиальных клеток - в процессах неоваскуляризации. Обсуждаются и анализируются участие VEGF-, Ang/Tie-зависимых и Notch-сигнальных путей, посттранскрипционной регуляции генома с участием микроРНК в процессах ангиогенеза

Сигнальный путь микроРНК-484 / Akt в регуляции чувствительности клеток рака молочной железы к противоопухолевым препаратам

The development of acquired resistance of malignant tumors to specific drugs, such as target and hormonal drugs, is usually associated with a rearrangement of the intracellular signaling network and activation of unblocked growth pathways. Epigenetic regulators, in particular, non-coding miRNAs that control the level of expression of specific signaling proteins, are directly involved in the development and maintenance of such changes. We have previously shown that the development of resistance of breast cancer cells to mTOR (mammalian target of rapamycin) inhibitors and hormonal drugs is accompanied by constitutive activation of protein kinase Akt, the key anti-apoptotic protein.Aim. To study the role of microRNAs in the regulation of Akt expression and the formation of a resistant phenotype of breast cancer cells.We have shown that Akt activation in the tamoxifen- or rapamycin-resistant MCF-7 sublines is associated with a decrease in the level of miRNA-484, one of the Akt suppressors. Transfection of microRNA-484 into MCF-7 cells does not affect the activity of estrogen signaling, but leads to a marked decrease in Akt expression and is accompanied by an increase in cell sensitivity to tamoxifen and rapamycin. The obtained data demonstrate the involvement of the miRNA-484 / Akt axis in the breast cancer cells’ sensitization to target and hormonal drugs, which allows us to consider miRNA-484 as a potential candidate for drug development to cure resistant cancers.Развитие приобретенной резистентности злокачественных опухолей к препаратам направленного действия, таким как таргетные и гормональные препараты, сопряжено с перестройкой внутриклеточной сигнальной сети и активацией незаблокированных путей передачи ростового сигнала. Непосредственное участие в развитии и поддержании подобных изменений принимают эпигенетические регуляторы, в частности некодирующие микроРНК, контролирующие уровень экспрессии конкретных сигнальных белков. Ранее мы показали, что развитие резистентности клеток рака молочной железы к ингибиторам mTOR (mammalian target of rapamycin) и блокаторам эстрогенового сигналинга сопровождается конститутивной активацией протеинкиназы Akt – основного антиапоптотического белка клеток. Цель настоящей работы – исследование роли отдельных микроРНК в регуляции экспрессии Akt и формировании резистентного фенотипа клеток рака молочной железы.Мы показали, что повышение активности протеинкиназы Akt в сублиниях MCF-7, резистентных к тамоксифену или рапамицину, ассоциировано со снижением уровня микроРНК-484 – одного из супрессоров Akt. Трансфекция в клетки MCF-7 микроРНК-484 не влияет на активность эстрогенового сигналинга, но приводит к выраженному снижению экспрессии Akt и сопровождается повышением чувствительноси клеток к тамоксифену и рапамицину. Полученные данные свидетельствуют об участии сигнального пути микроРНК-484 / Akt в сенсибилизации клеток рака молочной железы к действию таргетных и гормональных препаратов, что позволяет рассматривать микроРНК-484 в качестве перспективного кандидата для разработки на его основе новых противоопухолевых соединений

Measurement of Two-Particle Correlations of Hadrons in e⁺ e⁻ Collisions at Belle

The measurement of two-particle angular correlation functions in high-multiplicity e+e− collisions at √s=10.52  GeV is reported. In this study, the 89.5  fb−1 of hadronic e+e− annihilation data collected by the Belle detector at KEKB are used. Two-particle angular correlation functions are measured in the full relative azimuthal angle (Δϕ) and three units of pseudorapidity (Δη), defined by either the electron beam axis or the event-shape thrust axis, and are studied as a function of charged-particle multiplicity. The measurement in the thrust axis analysis, with mostly outgoing quark pairs determining the reference axis, is sensitive to the region of additional soft gluon emissions. No significant anisotropic collective behavior is observed with either coordinate analyses. Near-side jet correlations appear to be absent in the thrust axis analysis. The measurements are compared to predictions from various event generators and are expected to provide new constraints to the phenomenological models in the low-energy regime

Search for lepton-flavor-violating τ\tau decays into a lepton and a vector meson using the full Belle data sample

Charged-lepton-flavor-violation is predicted in several new physics scenarios. We update the analysis of $\tau$ lepton decays into a light charged lepton ($\ell$ = $e^{\pm}$ or $\mu^{\pm}$) and a vector meson ($V^0$ = $\rho^0$, $\phi$, $\omega$, $K^{\ast0}$, or $\overline{K}{}^{\ast0}$) using 980 fb$^{-1}$ of data collected with the Belle detector at the KEKB collider. No significant excess of such signal events is observed, and thus 90% credibility level upper limits are set on the $\tau \rightarrow \ell V^0$ branching fractions in the range of (1.7--$4.3) \times 10^{-8}$. These limits are improved by 30% on average from the previous results.Comment: 19 pages, 5 figures; added one sentence in Acknowledgments; added a systematic uncertainty about the number of background estimation, and corrected some sentence

Evidence for B0→pΣˉ0π−B^0 \to p\bar{\Sigma}^0\pi^- at Belle

We search for the $B^0\to p\bar{\Sigma}^0\pi^-$ decay with $\bar{\Sigma}^0 \to \bar{\Lambda}\gamma$, where the $\gamma$ is not measured, using a data sample corresponding to an integrated luminosity of 711 $\rm{fb^{-1}}$ which contains 772 $\times$ $10^{6}$ $B\bar{B}$ pairs, collected around the $\Upsilon$(4S) resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. We measure for the first time the $B^0\to p\bar{\Sigma}^0\pi^-$ branching fraction to be $\mathcal{B}(B^0 \to p \bar\Sigma^0 \pi^-) = (1.17^{+0.43}_{-0.40}(\text{stat})\pm 0.07(\text{syst})) \times 10^{-6}$ with a significance of $3.5\sigma$. We simultaneously measure the branching fraction for the related channel $B^{0}\to p\bar{\Lambda}\pi^{-}$ with much improved precision.Comment: 7 pages, 5 figures, 4 tables. To be submitted to PR

Measurement of the branching fraction of Ξc0→Λc+π−\Xi_{c}^{0}\to \Lambda_{c}^{+}\pi^{-} at Belle

Based on a data sample of 983 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we present the study of the heavy-flavor-conserving decay $\Xi_{c}^{0}\to \Lambda_{c}^{+}\pi^{-}$ with $\Lambda_{c}^{+}$ reconstructed via its $pK^{-} \pi^{+}$ decay mode. The branching fraction ratio $\mathcal{B}(\Xi_{c}^{0}\to \Lambda_{c}^{+}\pi^{-})/\mathcal{B}(\Xi_{c}^{0}\to \Xi^{-}\pi^{+})$ is measured to be $0.38 \pm 0.04 \pm 0.04$. Combing with the world average value of $\mathcal{B}(\Xi_{c}^{0}\to \Xi^{-}\pi^{+})$, the branching fraction $\mathcal{B}(\Xi_{c}^{0}\to \Lambda_{c}^{+}\pi^{-})$ is deduced to be $(0.54 \pm 0.05 \pm 0.05 \pm 0.12)\%$. Here, the uncertainties above are statistical, systematic, and from $\mathcal{B}(\Xi_c^{0} \to \Xi^{-}\pi^{+})$, respectively.Comment: 5 pages, 4 figure

Search for charged-lepton flavor violation in Υ(2S)→ℓ∓τ±\Upsilon(2S) \to \ell^\mp\tau^\pm (ℓ=e,μ\ell=e,\mu) decays at Belle

We report a search for the charged-lepton flavor violation in $\Upsilon(2S) \to \ell^\mp\tau^\pm$ ($\ell=e,\mu$) decays using a $25~\mathrm{fb}^{-1}$ $\Upsilon(2S)$ sample collected by the Belle detector at the KEKB $e^{+}e^{-}$ asymmetric-energy collider. We find no evidence for a signal and set upper limits on the branching fractions ($\mathcal{B}$) at 90$\%$ confidence level. We obtain the most stringent upper limits: $\mathcal{B}(\Upsilon(2S) \to \mu^{\mp}\tau^{\pm}) < 0.26 \times 10^{-6}$ and $\mathcal{B}(\Upsilon(2S) \to e^{\mp}\tau^{\pm}) < 1.02 \times 10^{-6}$.Comment: 11 pages, 3 figures, Submitted to JHE

Evidence for the decay ωc_{c}0^{0} →π+^{+} ω (2012)−^{-} →π+^{+} (K‾\overline{K} Ξ)−^{-}

Using a data sample of 980 fb$^{-1}$ collected with the Belle detector operating at the KEKB asymmetric-energy e$^{+}$e$^{-}$ collider, we present evidence for the Ω(2012)$^{-}$ in the resonant substructure of Ω$_{c}$$^{0}$ → π$^{+}$ ($\overline{K}$ Ξ)$^{-}$ (($\overline{K}$ Ξ)$^{-}$ = K$^{-}$Ξ$^{0}$ + K$^{0}$Ξ$^{-}$ ecays. The significance of the decays. The significance of the Ω(2012)$^{-}$ signal is 4.2σ after considering the systematic uncertainties. The ratio of the branching fraction of Ω$_{c}$$^{0}$ → π$^{+}$ Ω(2012)$^{-}$ π$^{+}$ ($\overline{K}$ Ξ)$^{-}$ relative to that of Ω$_{c}$$^{0}$ → π$^{+}$ Ω$^{-}$ is calculated to be 0.220±0.059(stat.)±0.035(syst.). The individual ratios of the branching fractions of the two isospin modes are also determined and found to be B (Ω$_{c}$$^{0}$ → π$^{+}$ Ω(2012)$^{-}$) x B(Ω(2012)$^{-}$ → $\overline{K}$ Ξ$^{0}$) / B(Ω$_{c}$$^{0}$ → π$^{+}$ K$^{-}$Ξ$^{0}$ = (9.6±3.2(stat.) ±1.8(syst.))% and B (Ω$_{c}$$^{0}$ → π$^{+}$ Ω(2012)$^{-}$) x B(Ω(2012)$^{-}$ → $\overline{K}$$^{0}$ Ξ$^{-}$) / B(Ω$_{c}$$^{0}$ → π$^{+}$ $\overline{K}$$^{0}$Ξ$^{-}$) =(5.5±2.8(stat.) ±0.7(syst.))