Kolmogorov scaling and intermittency in Rayleigh-Taylor turbulence

The Rayleigh--Taylor (RT) turbulence is investigated by means of high resolution numerical simulations. The main question addressed here is on whether RT phenomenology can be considered as a manifestation of universality of Navier--Stokes equations with respect to forcing mechanisms. At a theoretical level the situation is far from being firmly established and, indeed, contrasting predictions have been formulated. Our first aim here is to clarify the above controversy through a deep analysis of scaling behavior of relevant statistical observables. The effects of intermittency on the mean field scaling predictions is also discussed.Comment: 4 pages, 5 figure

EVALUATION OF EFFECTIVENESS OF ANTIVIRAL THERAPY FOR CHRONIC HEPATITIS C, CAUSED BY HCV GENOTYPE 6

Objectives: Evaluating the effectiveness of 2 therapeutic schemes for chronic hepatitis C (genotype 6) which combined sofosbuvir and ribavirin, one of them also included pegylated interferon. Materials and methods: The study included 110 patients with chronic hepatitis C (genotype 6), who have undergone antiviral therapy (HTP) in Hepatology Clinic inHo Chi Minh City,Vietnamfrom November 2015 to July 2016. 24 patients were treated by Pegylated interferon alfa-2a, ribavirin and sofosbuvir for 12 weeks, 86 patients – by sofosbuvir and ribavirin for 24 weeks. Non-interferon regimen was administered primarily to patients with contraindications to the use of interferon. To monitor the effectiveness of antiviral therapy, quantification of HCV RNA in serum was performed by PCR prior to treatment, at 4th, 12th or 24th week (depending on the observation group) from the starting of treatment and at 12th, 24th week after completion of treatment. Results: All patients, who were treated with pegylated interferon, ribavirin and sofosbuvir, completed the full course of treatment and 100% of them are registered with sustained virological response at 12th and 24th week after the end of antiviral therapy (SVR-12 and SVR-24, respectively). In the group of patients, who treated with ribavirin and sofosbuvir, 97,7% of patients completed full course of treatment (SVR-12 was registered in 93% of patients, and SVR-24 – in 91,9% of patients). Of 75 patients without a history of HCC, SVR24 was registered in 74 people (98,7%), of 11 patients with HCC – in 5 patients (45,5%). SVR-24 was registered in 98% of patients with cirrhosis (F4) without HCC. Conclusion: The results can serve as a justification for the use of these schemes of antiviral therapy for special groups of patients and/or conditions when it is impossible to follow the latest recommendations, which will help to expand the access of patients to effective antiviral therapy for chronic hepatitis C

Full coherent control of nuclear spins in an optically pumped single quantum dot

Highly polarized nuclear spins within a semiconductor quantum dot (QD) induce effective magnetic (Overhauser) fields of up to several Tesla acting on the electron spin or up to a few hundred mT for the hole spin. Recently this has been recognized as a resource for intrinsic control of QD-based spin quantum bits. However, only static long-lived Overhauser fields could be used. Here we demonstrate fast redirection on the microsecond time-scale of Overhauser fields of the order of 0.5 T experienced by a single electron spin in an optically pumped GaAs quantum dot. This has been achieved using full coherent control of an ensemble of 10^3-10^4 optically polarized nuclear spins by sequences of short radio-frequency (rf) pulses. These results open the way to a new class of experiments using rf techniques to achieve highly-correlated nuclear spins in quantum dots, such as adiabatic demagnetization in the rotating frame leading to sub-micro K nuclear spin temperatures, rapid adiabatic passage, and spin squeezing

Macro- and microscopic properties of strontium doped indium oxide

Solid state synthesis and physical mechanisms of electrical conductivity variation in polycrystalline, strontium doped indium oxide In2O3:(SrO)x were investigated for materials with different doping levels at different temperatures (T=20-300 C) and ambient atmosphere content including humidity and low pressure. Gas sensing ability of these compounds as well as the sample resistance appeared to increase by 4 and 8 orders of the magnitude, respectively, with the doping level increase from zero up to x=10%. The conductance variation due to doping is explained by two mechanisms: acceptor-like electrical activity of Sr as a point defect and appearance of an additional phase of SrIn2O4. An unusual property of high level (x=10%) doped samples is a possibility of extraordinarily large and fast oxygen exchange with ambient atmosphere at not very high temperatures (100-200 C). This peculiarity is explained by friable structure of crystallite surface. Friable structure provides relatively fast transition of samples from high to low resistive state at the expense of high conductance of the near surface layer of the grains. Microscopic study of the electro-diffusion process at the surface of oxygen deficient samples allowed estimation of the diffusion coefficient of oxygen vacancies in the friable surface layer at room temperature as 3x10^(-13) cm^2/s, which is by one order of the magnitude smaller than that known for amorphous indium oxide films.Comment: 19 pages, 7 figures, 39 reference

ОЦЕНКА ЭФФЕКТИВНОСТИ ПРОТИВОВИРУСНОЙ ТЕРАПИИ ХРОНИЧЕСКОГО ГЕПАТИТА C, ВЫЗВАННОГО ВИРУСОМ ГЕНОТИПА 6

Objectives: Evaluating the effectiveness of 2 therapeutic schemes for chronic hepatitis C (genotype 6) which combined sofosbuvir and ribavirin, one of them also included pegylated interferon. Materials and methods: The study included 110 patients with chronic hepatitis C (genotype 6), who have undergone antiviral therapy (HTP) in Hepatology Clinic inHo Chi Minh City,Vietnamfrom November 2015 to July 2016. 24 patients were treated by Pegylated interferon alfa-2a, ribavirin and sofosbuvir for 12 weeks, 86 patients – by sofosbuvir and ribavirin for 24 weeks. Non-interferon regimen was administered primarily to patients with contraindications to the use of interferon. To monitor the effectiveness of antiviral therapy, quantification of HCV RNA in serum was performed by PCR prior to treatment, at 4th, 12th or 24th week (depending on the observation group) from the starting of treatment and at 12th, 24th week after completion of treatment. Results: All patients, who were treated with pegylated interferon, ribavirin and sofosbuvir, completed the full course of treatment and 100% of them are registered with sustained virological response at 12th and 24th week after the end of antiviral therapy (SVR-12 and SVR-24, respectively). In the group of patients, who treated with ribavirin and sofosbuvir, 97,7% of patients completed full course of treatment (SVR-12 was registered in 93% of patients, and SVR-24 – in 91,9% of patients). Of 75 patients without a history of HCC, SVR24 was registered in 74 people (98,7%), of 11 patients with HCC – in 5 patients (45,5%). SVR-24 was registered in 98% of patients with cirrhosis (F4) without HCC. Conclusion: The results can serve as a justification for the use of these schemes of antiviral therapy for special groups of patients and/or conditions when it is impossible to follow the latest recommendations, which will help to expand the access of patients to effective antiviral therapy for chronic hepatitis C.Цель: оценка эффективности 2 схем комбинированной терапии ХГС (генотип 6) софосбувиром и рибавирином, одна их которых также включала пегилированный интерферон. Материалы и методы: в исследование включены 110 больных ХГС (генотип 6), прошедших курс противовирусной терапии (ПВТ) в клинике гепатологии в г. Хошимин, Вьетнам в ноябре 2015 г. – июле 2016 г. Пегилированный интерферон альфа-2а, софосбувир и рибавирин получали 24 человека в течение 12 недель, 86 больных в течение 24 недель принимали софосбувир и рибавирин. Безинтерфероновую схему лечения назначали прежде всего больным с противопоказаниями к применению интерферона. Для контроля эффективности ПВТ проводили количественное определение РНК ВГС в сыворотке крови методом ПЦР до начала лечения, через 4, 12 или 24 недели (в зависимости от группы наблюдения) от начала приема препаратов и через 12 и 24 недели после окончания курса терапии. Результаты: все больные, получавшие пегилированный интерферон, софосбувир и рибавирин, закончили полный курс лечения, и у 100% из них зарегистрирован устойчивый вирусологический ответ через 12 и 24 недели после окончания ПВТ (УВО-12 и УВО-24 соответственно). В группе больных, получавших софосбувир и рибавирин, полный курс лечения завершили 97,7% больных (УВО-12 зарегистрирован у 93% больных, а УВО-24 – у 91,9% пациентов). Из 75 больных без ГЦК в анамнезе УВО-24 зарегистрирован у 74 человек (98,7%), из 11 больных с ГЦК – у 5 пациентов (45,5%). УВО-24 зарегистрирован у 98% больных с циррозом печени (F4) без ГЦК. Заключение: полученные результаты могут служить обоснованием применения указанных схем ПВТ в особыхгруппах больных и/или условиях, когда не представляется возможным следовать новейшим рекомендациям, что будет способствовать расширению доступа больных к эффективной противовирусной терапии ХГС

КЛИНИКО-ЛАБОРАТОРНАЯ ХАРАКТЕРИСТИКА ХРОНИЧЕСКОГО ГЕПАТИТА С ВО ВЬЕТНАМЕ, НА ПРИМЕРЕ ГЕПАТОЛОГИЧЕСКОЙ КЛИНИКИ Г. ХОШИМИН

Objectives. To provide clinical  and laboratory  characteristics of chronic  hepatitis C in Vietnam.Materials and  methods. A retrospective analysis of data about  1870 HCV  patients observed at Hepatology Clinic  in Ho Chi Minh  City, Vietnam from 2010 to 2015.Results. Among observed patients, HCV  genotype 1 is predominant (48.8%), genotype 6 was  registered in 29,7% of patients, and genotype 2 – 18,7%. Advanced fibrosis (F3) and cirrhosis (F4) were detected in 52% of patients. The rate of chronic  co-infection with  hepatitis B viruse  and  hepatitis C virus is at 6% of patients. Nearly  one-tenth of all observed HCV patients (9%)  were diagnosed with hepatocellular carcinoma. In the  group  of patients who completed the  full course  of treatment, non-responsers to therapy and  have  virologic  breakthrough, SVR-24  was registered at 73,7% and 75,1% of patients treated with  simple or pegylated interferon, respectively. Thus,  combination therapy with interferonalpha  and  ribavirin  for the  indigenous Vietnamese population has been showed relatively high efficiency.Conclusion. The  findings about  clinical  and  laboratory characteristics of patients with  chronic  hepatitis C, and  the effectiveness of antiviral therapy, have practical importance for preparation a long-term strategy for the  elimination of hepatitis C in Vietnam.Цель  исследования: дать  клинико-лабораторную характеристику хронического гепатита С во Вьетнаме.Материалы и методы. Проведен ретроспективный анализ данных 1870 больных ХГС, наблюдавшихся в клинике  гепатологии в г. Хошимин, Вьетнам в 2010–2015 гг.Результаты. У наблюдаемых пациентов преобладал генотип 1 ВГС (48,8%), генотип 6 зарегистрирован у29,7% обследованных и генотип 2 – у 18,7%. Фиброз (F3) и цирроз печени (F4) были выявлены у 52% больных. Хроническая ко-инфекция вирусами гепатитов B и C установлена у 6%  больных. Почти у каждого десятого наблюдаемого больного ХГС  (9%)  диагностирована гепатоцеллюлярная карцинома. В группе больных, закончивших полный курс лечения, не ответивших на терапию и имеющих вирусологический прорыв, УВО-24 зарегистрировали у 73,7% и 75,1% пациентов, получавших простой или пегилированный интерфероны соответственно. Таким образом, у коренного населения Вьетнама показана достаточно высокая эффективность комбинированной терапии интерфероном-альфа и рибавирином.Заключение. Полученные данные о клинико-лабораторных характеристиках больных ХГС и эффективности противовирусной терапии имеют важное практическое значение для составления долгосрочной стратегии элиминации гепатита С во Вьетнаме

Spin alignment and violation of the OZI rule in exclusive ω\omega and ϕ\phi production in pp collisions

Exclusive production of the isoscalar vector mesons $\omega$ and $\phi$ is measured with a 190 GeV$/c$ proton beam impinging on a liquid hydrogen target. Cross section ratios are determined in three intervals of the Feynman variable $x_{F}$ of the fast proton. A significant violation of the OZI rule is found, confirming earlier findings. Its kinematic dependence on $x_{F}$ and on the invariant mass $M_{p\mathrm{V}}$ of the system formed by fast proton $p_\mathrm{fast}$ and vector meson $V$ is discussed in terms of diffractive production of $p_\mathrm{fast}V$ resonances in competition with central production. The measurement of the spin density matrix element $\rho_{00}$ of the vector mesons in different selected reference frames provides another handle to distinguish the contributions of these two major reaction types. Again, dependences of the alignment on $x_{F}$ and on $M_{p\mathrm{V}}$ are found. Most of the observations can be traced back to the existence of several excited baryon states contributing to $\omega$ production which are absent in the case of the $\phi$ meson. Removing the low-mass $M_{p\mathrm{V}}$ resonant region, the OZI rule is found to be violated by a factor of eight, independently of $x_\mathrm{F}$.Comment: 23 pages, 13 figures and 5 table

Measurement of the charged-pion polarisability

The COMPASS collaboration at CERN has investigated pion Compton scattering, $\pi^-\gamma\rightarrow \pi^-\gamma$, at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction $\pi^-\mathrm{Ni}\rightarrow\pi^-\gamma\;\mathrm{Ni}$, which is initiated by 190\,GeV pions impinging on a nickel target. The exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, $Q^2<0.0015$\,(GeV/$c$)$^2$. From a sample of 63\,000 events the pion electric polarisability is determined to be $\alpha_\pi\ =\ (\,2.0\ \pm\ 0.6_{\mbox{\scriptsize stat}}\ \pm\ 0.7_{\mbox{\scriptsize syst}}\,) \times 10^{-4}\,\mbox{fm}^3$under the assumption$\alpha_\pi=-\beta_\pi$, which relates the electric and magnetic dipole polarisabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction, that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambigiously known, was performed for an independent estimate of the systematic uncertainty.Comment: Published version: 9 pages, 3 figures, 1 tabl

Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton

Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.Comment: 15 pages, 13 figures and 1 tabl

Resonance Production and ππ\pi\pi S-wave in π−+p→π−π−π++precoil\pi^- + p \rightarrow \pi^- \pi^- \pi^+ + p_{recoil} at 190 GeV/c

The COMPASS collaboration has collected the currently largest data set on diffractively produced $\pi^-\pi^-\pi^+$ final states using a negative pion beam of 190 GeV/c momentum impinging on a stationary proton target. This data set allows for a systematic partial-wave analysis in 100 bins of three-pion mass, $0.5 < m_{3\pi} < 2.5$ GeV/c$^2$ , and in 11 bins of the reduced four-momentum transfer squared, $0.1 < t < 1.0$ (GeV/c)$^2$ . This two-dimensional analysis offers sensitivity to genuine one-step resonance production, i.e. the production of a state followed by its decay, as well as to more complex dynamical effects in nonresonant $3\pi$ production. In this paper, we present detailed studies on selected $3\pi$ partial waves with $J^{PC} = 0^{-+}$, $1^{++}$, $2^{-+}$, $2^{++}$, and $4^{++}$. In these waves, we observe the well-known ground-state mesons as well as a new narrow axial-vector meson $a_1(1420)$ decaying into $f_0(980) \pi$. In addition, we present the results of a novel method to extract the amplitude of the $\pi^-\pi^+$ subsystem with $I^{G}J^{PC} = 0^+ 0^{++}$ in various partial waves from the $\pi^-\pi^-\pi^+$ data. Evidence is found for correlation of the $f_0(980)$ and $f_0(1500)$ appearing as intermediate $\pi^- \pi^+$ isobars in the decay of the known $\pi(1800)$ and $\pi_2(1880)$.Comment: 96 page