39 research outputs found

    Semiclassical approaches to nuclear dynamics

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    The extended Gutzwiller trajectory approach is presented for the semiclassical description of nuclear collective dynamics, in line with the main topics of the fruitful activity of V.G. Solovjov. Within the Fermi-liquid droplet model, the leptodermous effective surface approximation was applied to calculations of energies, sum rules and transition densities for the neutron-proton asymmetry of the isovector giant-dipole resonance and found to be in good agreement with the experimental data. By using the Strutinsky shell correction method, the semiclassical collective transport coefficients such as nuclear inertia, friction, stiffness, and moments of inertia can be derived beyond the quantum perturbation approximation of the response function theory and the cranking model.The averaged particle-number dependence of the low-lying collective vibrational states are described in good agreement with basic experimental data, mainly due to an enhancement of the collective inertia as compared to its irrotational flow value. Shell components of the moment of inertia are derived in terms of the periodic-orbit free-energy shell corrections. A good agreement between the semiclassical extended Thomas-Fermi moments of inertia with shell corrections and the quantum results is obtained for different nuclear deformations and particle numbers. Shell effects are shown to be exponentially dampted out with increasing temperature in all the transport coefficients.Comment: 83 pages, 39 figures, 4 tables, corrected typos and improved Englis

    СРАВНИТЕЛЬНОЕ ИССЛЕДОВАНИЕ IN VITRO ЭКВИВАЛЕНТНОСТИ ДВУХКОМПОНЕНТНЫХ ДОЗИРОВАННЫХ АЭРОЗОЛЬНЫХ ИНГАЛЯТОРОВ С ПОМОЩЬЮ ИМПАКТОРА НОВОГО ПОКОЛЕНИЯ

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    Aim. To compare in vitro the aerodynamic particle size distributions of original and generic inhalers, which contain both fluticasone (FP) and salmeterol (SM).Material and methods. The Next Generation Impactor (NGI; Copley Ltd., UK) was used to assess the particle size distribution and aerosol quality of two products to determine the equivalence in the aerosol released from the device. The first formulation was Seretide (SM/FP) 25/250 μg, an original SM/FP fixed combination developed by GlaxoSmithKline. The second formulation tested was Tevacomb 25/250 μg (SM/FP), the generic SM/FP fixed combination produced by Cipla. The mass of FP and SM recovered from each stage of impactor was quantified via high performance liquid chromatography (HPLC). The impactor results were statistically evaluated by log transformation of the single data NGI. Results. Statistically significant differences were seen between the deposition profile of Seretide and Tevacomb obtained using the NGI. Evaluating the single stages results in estimation of nonequivalence for all stages except stage 5 (FP) since their confidence intervals (CI) were out of the range of the tight conventional bioequivalence limits of Ѓ} 15 % (0,85–1,18). Also differences were observed by number of parameters, including the fine particle dose (FPD), emitted dose (ED), mass median aerodynamic diameter (MMAD), and geometric standard deviation (GSD) of SM and FP. Conclusion. These in vitro findings suggest that the particle size distributions of the generic formulation Tevacomb is not equivalent to that of the original product Seretide. Тест на аэродинамическое распределение частиц моделирует in vitro процессы, происходящие при вдыхании пациентом дозы аэрозольного препарата. Цель. Сравнить in vitro эквивалентность воспроизведенного (Тевакомб) и оригинального (Серетид) дозированных аэрозольных ингаляторов, содержащих флутиказона пропионат и салметерола ксинафоат по показателю «аэродинамическое распределение частиц». Материалы и методы. Исследуемые дозированные аэрозольные ингаляторы: Серетид, 25/250 (салметерола ксинафоат/флутиказона пропионат) мкг/доза, производство ГлаксоСмитКляйн Фармасьютикалсз, Польша, и Тевакомб, 25/250 (салметерола ксинафоат/флутиказона пропионат) мкг/доза, производство Ципла Лтд, Индия. В исследовании изучали по 6 образцов каждого из наименований ингалятора. Для моделирования in vitro вдоха пациента использовали 7-ступенчатый каскадный импактор нового поколения. Скорость потока воздуха через импактор составляла 30 Ѓ} 1 л/мин. Время ввода дозы аэрозоля — 8 с. К фракции мелкодисперсных частиц относили частицы с диаметром < 5 мкм. Количественный анализ частиц флутиказона пропионата и салметерола ксинафоата, собранных на ступенях импактора, проводили в соответствии с методами, описанными в Европейской фармакопее 6-го изд. Результаты. Результаты изучения аэродинамического распределения частиц на единичных ступенях показали статистически достоверное отличие между оригинальным и воспроизведенным дозированными аэрозольными ингаляторами. На всех ступенях, за исключением 5-й (для флутиказона пропионата), 90% доверительные интервалы не укладывались в нормируемый диапазон Ѓ} 15% (0,85–1,18). Различия подтвердились при определении таких статистически значимых параметров, как массмедианный аэродинамический диаметр частиц и геометрическое стандартное отклонение от массмедианного аэродинамического диаметра, а также значений фракции мелкодисперсных частиц (ФМЧ) и величины выпущенной дозы. Для салметерола ксинафоата величины ФМЧ составляли 42,06% (оригинальный ингалятор) и 35,53% (воспроизведенный ингалятор), для флутиказона пропионата — 42,94 и 35,44%, соответственно. Заключение. Результаты теста на аэродинамическое распределение частиц показали неэквивалентность обоих дозированных аэрозольных ингаляторов, что может обусловливать различия в фармакологических эффектах данных препаратов

    Radiations and male fertility

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    During recent years, an increasing percentage of male infertility has to be attributed to an array of environmental, health and lifestyle factors. Male infertility is likely to be affected by the intense exposure to heat and extreme exposure to pesticides, radiations, radioactivity and other hazardous substances. We are surrounded by several types of ionizing and non-ionizing radiations and both have recognized causative effects on spermatogenesis. Since it is impossible to cover all types of radiation sources and their biological effects under a single title, this review is focusing on radiation deriving from cell phones, laptops, Wi-Fi and microwave ovens, as these are the most common sources of non-ionizing radiations, which may contribute to the cause of infertility by exploring the effect of exposure to radiofrequency radiations on the male fertility pattern. From currently available studies it is clear that radiofrequency electromagnetic fields (RF-EMF) have deleterious effects on sperm parameters (like sperm count, morphology, motility), affects the role of kinases in cellular metabolism and the endocrine system, and produces genotoxicity, genomic instability and oxidative stress. This is followed with protective measures for these radiations and future recommendations. The study concludes that the RF-EMF may induce oxidative stress with an increased level of reactive oxygen species, which may lead to infertility. This has been concluded based on available evidences from in vitro and in vivo studies suggesting that RF-EMF exposure negatively affects sperm quality

    Semiclassical and quantum shell-structure calculations of the moment of inertia

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    International audienceShell corrections to the moment of inertia (MI) are calculated for a Woods–Saxon potential of spheroidal shape and at different deformations. This model potential is chosen to have a large depth and a small surface diffuseness which makes it resemble the analytically solved spheroidal cavity in the semiclassical approximation. For the consistent statistical-equilibrium collective rotations under consideration here, the MI is obtained within the cranking model in an approach which goes beyond the quantum perturbation approximation based on the nonperturbative energy spectrum, and is therefore applicable to much higher angular momenta. For the calculation of the MI shell corrections δΘ, the Strutinsky smoothing procedure is used to obtain the average occupation numbers of the particle density generated by the resolution of the Woods–Saxon eigenvalue problem. One finds that the major-shell structure of δΘ, as determined in the adiabatic approximation, is rooted, for large as well as for small surface deformations, in the same inhomogenuity of the distribution of single-particle states near the Fermi surface as the energy shell corrections δE. This fundamental property is in agreement with the semiclassical results δΘ ∝ δE obtained analytically within the non perturbative periodic orbit theory for any potential well, in particular for the spheroidal cavity, and for any deformation, even for large deformations where bifurcations of the equatorial orbits play a substantial role. Since the adiabatic approximation, ω ≪ Ω, with ℏΩ the distance between major nuclear shells, is easily obeyed even for large angular momenta typical for high-spin physics at large particle numbers, our model approach seems to represent a tool that could, indeed, be very useful for the description of such nuclear systems
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