Ferromagnetic Polarons in La0.5Ca0.5MnO3 and La0.33Ca0.67MnO3

Unrestricted Hartree-Fock calculations on La0.5Ca0.5MnO3 and La0.33Ca0.67MnO3 in the full magnetic unit cell show that the magnetic ground states of these compounds consist of 'ferromagnetic molecules' or polarons ordered in herring-bone patterns. Each polaron consists of either three or five Mn ions separated by O- ions with a magnetic moment opposed to those of the Mn ions. Ferromagnetic coupling within the polarons is strong while coupling between them is relatively weak. Magnetic moments on the Mn ions range between 3.8 and 3.9 Bohr magnetons in La0.5Ca0.5MnO3 and moments on the O- ions are -0.7 Bohr magnetons. Each polaron has a net magnetic moment of 7.0 Bohr magnetons, in good agreement with recently reported magnetisation measurements from electron microscopy. The polaronic nature of the electronic structure reported here is obviously related to the Zener polaron model recently proposed for Pr0.6Ca0.4MnO3 on the basis of neutron scattering data.Comment: 4 pages 5 figure

Sinusoidal cells and cytokine response in the tetrachloromethane-induced hepatotoxicity and an approach to its correction

High occurence of liver diseases (toxic, viral hepatitis, liver failure, cirrhosis) requires urgent search of new methods for management of the hepatobiliary diseases. At the present time, the role of immune mechanisms in pathogenesis of diffuse toxic liver damage is not finally clarified. The model of toxic hepatitis induced by carbon tetrachloride (CCl4) is widely known, but this approach allows us to perform complex evaluation and develop the methods for adequate correction of liver disorders in experimental model, which is not always feasible in clinical setting. To design a model of diffuse toxic liver damage, the CCl4 oil solution was used, having been administered intraperitoneally to experimental animals, at a single dose of 50 mg per 100 g body mass. Aiming for correction of toxic liver damage, the injections of aminophthalhydrazide (APH) to experimental animals were carried out intramuscularly at the dose of 2 mg/kg over the terms of experiment. An evaluation of the role of sinusoidal cells (SC) and cytokine production at the local and systemic level were carried out in the model of toxic liver damage caused by CCl4 and its correction by APH treatment. In the course of developing diffuse toxic liver damage induced by CCl4, the production of proinflammatory cytokines TNFα, IL-1α and IL-18 was enhanced at the local level, whereas an increase in TNFα concentration was observed in blood plasma. Following aminophthalhydrazide (APH) administration, the concentrations of proinflammatory cytokines (TNFα and IL-18) decreased at system level, along with locally decreased levels of IL-6 and IFNγ. Changes in the functional state of immunocompetent cells, which include sinusoidal cells (SC), have a significant impact on the development of pathological processes in the liver. The results of our study presume that, over the early periods of toxic impact upon liver tissue, the number of SCs increases both due to influx of blood monocytes and mature macrophages from the peritoneal cavity that enter the injury site directly via mesothelial layer. The SCs provide phagocytosis of damaged hepatocytes and contribute to resolution of the inflammatory process. Modulation of the macrophage activities by APH contributes to increased amounts of SCs at the early stages, and stabilizes their quantities after 2 weeks of APH injections. Change in the numbers of liver SCs during toxic damage affects the production of cytokines. A direct effect of APH upon the SCs may change the production of regulatory factors and compensate the insufficient rate of recovery processes after the toxic damage. © 2019, SPb RAACI

Опыт применения N-ацетилцистеина в комплексном лечении среднетяжелой COVID-ассоциированной пневмонии

The need for safe and effective treatment is becoming increasingly urgent due to the high COVID-19 mortality rates observed worldwide. The choice of drug products for COVID-19 treatment regimens is based on the efficacy and safety data, the mechanism of action, and potential interactions. N-acetylcysteine's (NAC) pharmacological activity and its potential to suppress the progression of COVID-19 make it a promising therapeutic agent for COVID-19. Aim of the study was to evaluate the efficacy of NAC in the complex treatment of moderate COVID-associated pneumonia. Methods. The study included adult patients (n = 46) with moderate COVID-associated (the 2nd degree on CT) pneumonia (age 57 (51; 71) years, body mass index - 30 (27.1; 32.3) kg/m2, duration of the disease before hospitalization - 7 (6; 8) days, body temperature at the admission - 37.5 (37.1; 37.8)°С). The patients were randomized into two study groups. The 1st group (n= 22) received standard COVID-19 treatment [1]. The 2nd group (n= 24) additionally received NAC 1,200 - 1,500 mg/day intravenously. Treatment with NAC was started together with the standard therapy. Results. Our study showed that the inclusion of NAC in the complex treatment of moderate COVID-associated pneumonia led to a statistically significant increase in blood oxygen saturation, oxygenation index, the difference in delta increase in oxygenation index, a quicker reduction in the volume of lung damage and the difference between the groups in delta reduction of this index. Also, the rate of reduction of C-reactive protein and reduction of the duration of hospitalization in the group of patients who received NAC was statistically significantly more profound than in the standard treatment group. Conclusion. The study confirmed the effectiveness of NAC as a part of the complex treatment of moderate COVID-associated pneumonia.Потребность в безопасном и эффективном лечении COVID-19 становится все более актуальной из-за высоких показателей смертности в мире. Выбор лекарственных средств (ЛС), входящих в схемы лечения COVID-19, основан на данных об их эффективности и безопасности, механизме их действия и потенциальных взаимодействий. Фармакологическая активность N-ацетилцистеина (NAC) и потенциально возможное действие в подавлении прогрессирования COVID-19 делают его многообещающим терапевтическим средством при COVID-19. Целью исследования явилась оценка эффективности NAC в комплексном лечении среднетяжелой COVID-ассоциированной пневмонии. Материалы и методы. В исследование включены взрослые пациенты (п = 46; возраст — 57 (51; 71) лет, индекс массы тела - 30 (27,1; 32,3) кг / м2, продолжительность заболевания до госпитализации - 7 (6; 8) дней, температура тела на момент госпитализации — 37,5 (37,1; 37,8) °С) со среднетяжелой (II степень по данным компьютерной томографии) COVID-ассоциированной пневмонией. Случайным образом сформированы 2 группы: пациенты 1-й группы (n = 22) получали стандартное лечение COVID-19; больные 2-й (n = 24) группы дополнительно получали NAC 1 200-1 500 мг в сутки внутривенно капельно. NAC назначался одновременно с началом стандартной терапии. Результаты. По данным исследования показано, что при включении в комплексное лечение среднетяжелой COVID-ассоциированной пневмонии NAC статистически значимо повысились уровень насыщения крови кислородом, индекс оксигенации, различия разности дельта (Δ), индекс оксигенации, скорость снижения объема поражения легких и межгрупповое различие Δ уменьшения данного показателя. Отмечены статистически значимо более интенсивная, чем в группе стандартного лечения, скорость снижения уровня С-реактивного белка, а также сокращение продолжительности госпитализации в группе пациентов, получавших NAC. Заключение. Результаты проведенного исследования свидетельствуют об эффективности включения NAC в комплексное лечение среднетяжелой COVID-ассоциированной пневмонии

Improved measurement of time-dependent CP violation in B0 -> J/Psi pi0 decays

We report improved measurements of time-dependent CP violation parameters for $B^0(\bar{B}^0) \to J/\psi \pi^0$ decay. This analysis is based on 535 million $B\bar{B}$ pairs accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. From the distribution of proper time intervals between the two B decays, we obtain the following CP violation parameters $\mathcal{S}_{J/\psi \pi^0} = -0.65\pm0.21 (\rm{stat})\pm0.05 (\rm{syst})$ and $\mathcal{A}_{J/\psi \pi^0} = +0.08\pm0.16 (\rm{stat})\pm0.05 (\rm{syst})$, which are consistent with Standard Model expectations.Comment: Resubmitted to PRD(RC), including 4 figures, 6pages Revision has been made according to communication with PRD referee

Study of B -> D** l nu with full reconstruction tagging

We report a study of semileptonic B decays to P-wave D** mesons. Semileptonic decay to D*_2 meson is observed for the first time and its product branching ratio is measured to be Br(B+ -> anti-D*0_2 l+nu) x Br(anti-D*0_2 -> D- pi+) = 0.22 +- 0.03(stat.) +- 0.04(syst.)%. The result is obtained using the fully reconstructed B tags from a data sample that contains 657 millions BB-bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ e- collider.Comment: 12 pages, 4 figures, submitted to PRD(RC

Observation of Two Resonant Structures in e+e- to pi+ pi- psi(2S) via Initial State Radiation at Belle

The cross section for e+e- to pi+ pi- psi(2S) between threshold and \sqrt{s}=5.5 GeV is measured using 673 fb^{-1} of data on and off the \Upsilon(4S) resonance collected with the Belle detector at KEKB. Two resonant structures are observed in the pi+ pi- psi(2S) invariant mass distribution, one at 4361\pm 9\pm 9 MeV/c2 with a width of 74\pm 15\pm 10 MeV/c2, and another at 4664\pm 11\pm 5 MeV/c2 with a width of 48\pm 15\pm 3 MeV/c2, if the mass spectrum is parameterized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.Comment: 10 pages, 5 figures, 2 tables, version to appear in Phys. Rev. Let

Electronic Structure and Valence Band Spectra of Bi4Ti3O12

The x-ray photoelectron valence band spectrum and x-ray emission valence-band spectra (Ti K _beta_5, Ti L_alpha, O K_alpha) of Bi4Ti3O12 are presented (analyzed in the common energy scale) and interpreted on the basis of a band-structure calculation for an idealized I4/mmm structure of this material.Comment: 6 pages + 7 PostScript figures, RevTex3.0, to be published in Phys.Rev.B52 (Oct.95). Figures also available via anonymous ftp at ftp://ftp.physik.uni-osnabrueck.de/pub/apostnik/BiTiO

Study of the suppressed B meson decay B^- -> D K^-, D -> K^+ \pi^-

We report a study of the suppressed B meson decay B^- -> D K^- followed by D -> K^+ \pi^-, where D indicates a D^0 or \bar{D}^0 state. The two decay paths interfere and provide information on the CP-violating angle \phi_3. We use a data sample containing 657 x 10^6 B\bar{B} pairs recorded at the \Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- storage ring. We do not find significant evidence for the mode B^- -> D K^-, D -> K^+ \pi^-, and set an upper limit of r_B < 0.19, where r_B is the magnitude of the ratio of amplitudes |A(B^- -> \bar{D}^0 K^-)/A(B^- -> D^0 K^-)|. The decay B^- -> D \pi^-, D -> K^+ \pi^- is also analyzed as a reference, for which we observe a signal with 6.6\sigma significance, and measure the charge asymmetry A_{D\pi} to be -0.02^{+0.15}_{-0.16}(stat) \pm 0.04(syst). In addition, the ratio B(B^- -> D^0 K^-)/B(B^- -> D^0 \pi^-) is measured to be [6.77 \pm 0.23(stat) \pm 0.30(syst)] x 10^{-2}.Comment: 6 pages, 3 figures, 2 table

Measurement of e^+e^- to pi^+pi^-J/psi Cross Section via Initial State Radiation at Belle

The cross section for e^+e^- to pi^+pi^-J/psi between 3.8 and 5.5 GeV/c^2 is measured using a 548 fb^{-1} data sample collected on or near the Upsilon(4S) resonance with the Belle detector at KEKB. A peak near 4.25 GeV/c^2, corresponding to the so called Y(4260), is observed. In addition, there is another cluster of events at around 4.05 GeV/c^2. A fit using two interfering Breit-Wigner shapes describes the data better than one that uses only the Y(4260), especially for the lower mass side of the 4.25 GeV enhancement.Comment: 11 pages, 5 figures, 2 tables; version to appear in PR

Improved search for D^0 mixing using semileptonic decays at Belle

A search for mixing in the neutral D meson system has been performed using semileptonic D0 -> K(*)- e+ \nu and D0 -> K(*)- \mu+ \nu decays. Neutral D mesons from D*+ -> D0 \pi_s^+ decays are used and the flavor at production is tagged by the charge of the slow pion. The measurement is performed using 492 fb^-1 of data recorded by the Belle detector. From the yield of right-sign and wrong-sign decays arising from non-mixed and mixed events, respectively, we measure the ratio of the time-integrated mixing rate to the unmixed rate to be R_M = (1.3 +- 2.2 +- 2.0) x 10^-4. This corresponds to an upper limit of R_M < 6.1 x 10^-4 at the 90% C.L.Comment: 20 pages, 16 figures, 8 tables; accepted by PRD; changes from previous version: minor rewording